Fathom Digital Manufacturing Corporation - Ordinary Shares (FATH) 10-K 8 Apr 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 28, 2022
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
Entity Registrant Name	FATHOM DIGITAL MANUFACTURING CORPORATION
Entity Central Index Key	0001836176
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Current Reporting Status	Yes
Entity Public Float		$ 67,287,574
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity File Number	001-39994
Entity Tax Identification Number	98-1571400
Entity Address, Address Line One	1050 Walnut Ridge Drive
Entity Address, City or Town	Hartland
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	53029
City Area Code	262
Local Phone Number	367-8254
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Document Annual Report	true
Document Transition Report	false
Auditor Name	GRANT THORNTON LLP
Auditor Firm ID	248
Auditor Location	Milwaukee, WI
Documents Incorporated by Reference [Text Block]	DOCUMENTS INCORPORATED BY REFERENCE None.
Class A Common Stock [Member]
Document Information [Line Items]
Trading Symbol	FATH
Entity Common Stock, Shares Outstanding		50,785,656
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Security Exchange Name	NYSE
Warrants to Purchase Class A Common Stock [Member]
Document Information [Line Items]
Trading Symbol	FATH.WS
Title of 12(b) Security	Warrants to purchase Class A common stock
Security Exchange Name	NYSE
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		84,294,971

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2021		Dec. 31, 2020
Current assets
Cash	[1]	$ 20,357		$ 8,188
Accounts receivable, net	[1]	25,367		15,563
Inventory	[1]	13,165		6,325
Prepaid expenses and other current assets	[1]	1,836		2,598
Total current assets	[1]	60,725		32,674
Property and equipment, net	[1]	44,527		26,386
Intangible & Other	[1]	269,622		83,466
Goodwill	[1]	1,189,464		63,215
Other non-current assets	[1]	2,036		1,038
Total assets	[1]	1,566,374		206,779
Current liabilities
Accounts payable	[1],[2]	9,409		4,404
Accrued expenses	[1]	5,957		4,181
Other current liabilities	[1]	2,058		2,778
Contingent consideration	[1]	2,748		4,066
Current portion of debt	[1]	29,697		2,853
Total current liabilities	[1]	49,869		18,282
Long-term debt, net	[1]	120,491		90,486
Fathom earnout shares liability	[1]	64,300		0
Sponsor Earnout Shares Liability	[1]	9,380		0
Long-term contingent consideration	[1]	850		7,373
Deferred tax liability	[1]	17,570		0
Other non-current liabilities	[1]	4,655		514
Warrant Liability	[1]	33,900		0
Payable to related parties pursuant to the TRA	[1]	4,600		0
Total liabilities	[1]	305,615		116,655
Commitments and Contingencies
Class A contingently redeemable preferred units; $100 par value, authorized 1,167,418 units, issued and outstanding as of December 31, 2020.	[1]	0		54,105
Redeemable non-controlling interest in Fathom OpCo	[1]	841,982		0
Shareholders' and Members' Equity:
Preferred Stock, $.0001 par value; 10,000,000 shares authorized; 0 shares issued and outstanding as of December 31, 2021	[1]	0		0
Additional paid-in capital	[1]	466,345		0
Accumulated other comprehensive loss	[1]	0		(68)
Accumulated deficit	[1]	(47,581)		(14,232)
Members' equity	[1]	0		36,019
Shareholders' equity attributable to Fathom Digital Manufacturing Corporation		418,777	[1]	36,019	[3]
Total Members' Equity and Class A contingently redeemable preferred equity (Predecessor)	[1]	0		90,124
Total Liabilities, Shareholders' Equity, Members' Equity, Redeemable Non-Controlling Interest and Class A Contingently Redeemable Preferred Equity	[1]	1,566,374		206,779
Class A Common Stock [Member]
Shareholders' and Members' Equity:
Common stock	[1]	5		0
Class B Common Stock [Member]
Shareholders' and Members' Equity:
Common stock	[1]	8		0
Class C Common Stock [Member]
Shareholders' and Members' Equity:
Common stock	[1]	0		0
Class A Common Units [Member]
Shareholders' and Members' Equity:
Common units	[1]	0		35,869
Class B Common Units [Member]
Shareholders' and Members' Equity:
Common units	[1]	$ 0		$ 14,450
[1]	See accompanying notes to the consolidated financial statements.
[2]	Inclusive of accounts payable to related parties of $ 1,246 and $ 541 as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor), respectively.
[3]	See accompanying notes to the consolidated financial statements.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares authorized (in shares)	10,000,000
Preferred stock, shares issued (in shares)	0
Preferred stock, shares outstanding (in shares)	0
Common stock, shares authorized (in shares)	500,000,000
Accounts payable, Related parties, Current	$ 1,246	$ 541
Class A Contingently Redeemable Preferred Units [Member]
Redeemable preferred units, par value (in dollars per share)		$ 100
Redeemable preferred units, authorized (in shares)		1,167,418
Redeemable preferred units, issued (in shares)		1,167,418
Class A Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.0001
Common stock, shares authorized (in shares)	300,000,000
Common stock, shares issued (in shares)	50,785,656
Common stock, shares outstanding	50,785,656
Class B Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.0001
Common stock, shares authorized (in shares)	180,000,000
Common stock, shares issued (in shares)	84,294,971
Common stock, shares outstanding	84,294,971
Class C Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.0001
Common stock, shares authorized (in shares)	10,000,000
Common stock, shares issued (in shares)	0
Common stock, shares outstanding	0
Class A Common Units [Member]
Common stock, par value (in dollars per share)		$ 100
Common stock, shares authorized (in shares)		5,480,611
Common stock, shares issued (in shares)		5,480,611
Common stock, shares outstanding		5,480,611
Class B Common Units [Member]
Common stock, par value (in dollars per share)		$ 100
Common stock, shares authorized (in shares)		2,242,981
Common stock, shares issued (in shares)		2,242,981
Common stock, shares outstanding		2,242,981

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Income Statement [Abstract]
Revenue	[1]	$ 4,840		$ 147,356		$ 61,289
Cost of revenue	[1],[2],[3]	2,725		90,278		33,064
Gross profit	[1]	2,115		57,078		28,225
Operating expenses
Selling, general, and administrative	[1],[4]	3,133		37,507		24,642
Depreciation and amortization	[1]	416		10,357		4,672
Total operating expenses	[1]	3,549		47,864		29,314
Operating (loss) income	[1]	(1,434)		9,214		(1,089)
Interest expense and other expense (income)
Interest expense	[1]	251		13,063		3,635
Other expense	[1]	308		21,007		3,824
Other income	[1]	(35,460)		(5,174)		(585)
Total interest expense and other (income) expense, net.	[1]	(34,901)		28,896		6,874
Net income (loss) before income tax	[1]	33,467		(19,682)		(7,963)
Income tax benefit		(3)	[1]	(3,208)	[1]	0
Net income (loss)	[1]	33,470		(16,474)		(7,963)
Net loss attributable to Fathom OpCo non-controlling interest (Note 14)	[1]	(968)
Net income attributable to controlling interest		34,438	[1]	(16,474)	[5]	(7,963)	[5]
Comprehensive income (loss):
Gain (loss) from foreign currency translation	[1]			113		(68)
Comprehensive income (loss), net of tax	[1]	$ 34,438		$ (16,361)		$ (8,031)
Net income (loss) per unit attributable to Class A and Class B common unit holders
Basic and Diluted Earnings Per Unit	[1],[6]			$ (3.33)		$ (2.68)
Weighted average Class A and Class B units outstanding
Basic and Diluted	[1]			7,723,592		5,227,816
Net income per share attributable to shares of Class A common stock
Basic	[1]	$ 0.68
Diluted	[1]	$ 0.25
Weighted average shares outstanding
Basic	[1]	50,785,656
Diluted	[1]	135,839,973
[1]	See accompanying notes to the consolidated financial statements.
[2]	Inclusive of $ 94 , $ 5,751 , and $ 2,567 of depreciation and amortization for the periods ended December 23 - 31, 2021, January 1 - December 22, 2021, and January 1 - December 31, 2020, respectively.
[3]	Inclusive of $ 700 , $ 9,165 , and $ 4,434 of cost of revenue related to inventory purchases from a related party for the periods ended December 23 - 31, 2021, January 1 - December 22, 2021, and January 1 - December 31,2020, respectively. See Note 17.
[4]	Inclusive of $ 0 , $ 1,723 , and $ 722 of management fees incurred to a related party for the periods ended December 23 - 31, 2021, January 1 - December 22, 2021, and January 1 - December 31 2020, respectively. See Note 17.
[5]	See accompanying notes to the consolidated financial statements.
[6]	Basic and diluted net loss per unit amounts are the same for both Class A common units and Class B common units. See Note 13.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Cost, depreciation and amortization	$ 94	$ 5,751	$ 2,567
Management Services Agreement [Member]
Related party transaction, expenses	0	1,723	722
Related Party [Member]
Cost, inventory purchases from related party	$ 700	$ 9,165	$ 4,434

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity and Redeemable Non-Controlling Interest (Successor) and Class A Contingently Redeemable Preferred Units and Members' Equity (Predecessor) - USD ($) $ in Thousands		Total		Class A Common Stock	Class B Common Stock	Class A Contingently Redeemable Preferred Equity		Common StockClass A Common Stock		Common StockClass B Common Stock		Common StockLimited Liability Company Class A Common Units		Common StockLimited Liability Company Class B Common Units		Additional Paid-in Capital	Accumulated Deficit		Accumulated Other Comprehensive Income (Loss)		Redeemable Noncontrolling Interest
Opening Balance, Shares, Contingently Redeemable Preferred Units at Dec. 31, 2019	[1]					702,493
Opening Balance, Value, Contingently Redeemable Preferred Units at Dec. 31, 2019	[1]					$ 31,836
Shareholders' equity beginning balance at Dec. 31, 2019	[1]	$ 22,899										$ 18,701		$ 10,467			$ (6,269)
Shareholders' equity beginning balance (in shares) at Dec. 31, 2019	[1]											2,883,452		1,567,546
Members’ contributions	[1]	19,686		$ 17,168	$ 2,518
Members' contributions, Shares	[1]			2,597,159	380,906
Members' contributions, Value, Contingently Redeemable Preferred Units	[1]					$ 20,759
Members' contributions, Shares, Contingently Redeemable Preferred Units	[1]					423,083
Issuance of member interests	[1]	1,431			$ 1,431
Issuance of member interests, Shares	[1]				294,529
Issuance of member interests, Value, Contingently Redeemable Preferred Units	[1]					$ 1,510
Issuance of member interests, Shares, Contingently Redeemable Preferred Units	[1]					41,842
Share based compensation	[1]	34			$ 34
Net income (loss)		(7,963)	[1]		(2,583)												(7,963)	[1]
Gain (loss) from foreign currency translation		(68)	[2]																$ (68)	[1]
Closing Balance, Value, Redeemable Noncontrolling Interest at Dec. 31, 2020	[3]	0
Shareholders' equity ending balance at Dec. 31, 2020	[1]	36,019										$ 35,869		$ 14,450			(14,232)		(68)
Shareholders' equity ending balance (in shares) at Dec. 31, 2020	[1]											5,480,611		2,242,981
Ending Balance, Value, Contingently Redeemable Preferred Units at Dec. 31, 2020		54,105	[3]			$ 54,105	[1]
Ending Balance, Shares, Contingently Redeemable Preferred Units at Dec. 31, 2020	[1]					1,167,418
Share based compensation	[1]	2,649		$ 2,649
Net income (loss)		(16,474)	[1]		$ (4,784)												(16,474)	[1]
Gain (loss) from foreign currency translation		113	[2]																113	[1]
Closing Balance, Value, Redeemable Noncontrolling Interest at Dec. 22, 2021	[4]																				$ 842,950
Shareholders' equity ending balance at Dec. 22, 2021		22,307	[1]							$ 8	[4]	$ 38,518	[1]	$ 14,450	[1]		(30,706)	[1]	(45)	[1]
Shareholder's equity ending balance at Dec. 22, 2021	[4]	384,200						$ 5								$ 466,206	(82,019)
Shareholders' equity ending balance (in shares) at Dec. 22, 2021								50,785,656	[4]	84,284,971	[4]	5,480,611	[1]	2,242,981	[1]
Ending Balance, Value, Contingently Redeemable Preferred Units at Dec. 22, 2021	[1]					$ 54,105
Ending Balance, Shares, Contingently Redeemable Preferred Units at Dec. 22, 2021	[1]					1,167,418
Opening Balance, Shares, Contingently Redeemable Preferred Units at Dec. 31, 2020	[1]					1,167,418
Opening Balance, Value, Contingently Redeemable Preferred Units at Dec. 31, 2020		54,105	[3]			$ 54,105	[1]
Shareholders' equity beginning balance at Dec. 31, 2020	[1]	36,019										$ 35,869		$ 14,450			(14,232)		(68)
Shareholders' equity beginning balance (in shares) at Dec. 31, 2020	[1]											5,480,611		2,242,981
Opening Balance, Value, Redeemable Noncontrolling Interest at Dec. 31, 2020	[3]	0
Closing Balance, Value, Redeemable Noncontrolling Interest at Dec. 31, 2021		841,982	[3]																		841,982	[4]
Shareholders' equity ending balance at Dec. 31, 2021	[3]	418,777
Shareholder's equity ending balance at Dec. 31, 2021	[4]	418,777						$ 5		$ 8						466,345	(47,581)
Shareholders' equity ending balance (in shares) at Dec. 31, 2021	[4]							50,785,656		84,284,971
Ending Balance, Value, Contingently Redeemable Preferred Units at Dec. 31, 2021	[3]	0
Opening Balance, Shares, Contingently Redeemable Preferred Units at Dec. 22, 2021	[1]					1,167,418
Opening Balance, Value, Contingently Redeemable Preferred Units at Dec. 22, 2021	[1]					$ 54,105
Shareholder's equity beginning balance at Dec. 22, 2021	[4]	384,200						$ 5								466,206	(82,019)
Shareholders' equity beginning balance at Dec. 22, 2021		22,307	[1]							$ 8	[4]	$ 38,518	[1]	$ 14,450	[1]		(30,706)	[1]	$ (45)	[1]
Shareholders' equity beginning balance (in shares) at Dec. 22, 2021								50,785,656	[4]	84,284,971	[4]	5,480,611	[1]	2,242,981	[1]
Opening Balance, Value, Redeemable Noncontrolling Interest at Dec. 22, 2021	[4]																				842,950
Equity based compensation	[4]	139														139
Net income (loss)		34,438	[2]														34,438	[4]			(968)	[4]
Closing Balance, Value, Redeemable Noncontrolling Interest at Dec. 31, 2021		841,982	[3]																		$ 841,982	[4]
Shareholders' equity ending balance at Dec. 31, 2021	[3]	418,777
Shareholder's equity ending balance at Dec. 31, 2021	[4]	418,777						$ 5		$ 8						$ 466,345	$ (47,581)
Shareholders' equity ending balance (in shares) at Dec. 31, 2021	[4]							50,785,656		84,284,971
Ending Balance, Value, Contingently Redeemable Preferred Units at Dec. 31, 2021	[3]	$ 0
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.
[3]	See accompanying notes to the consolidated financial statements.
[4]	See accompanying notes to the consolidated financial statements.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Cash Flows from Operating Activities
Net Income (loss)	[1]	$ 33,470	$ (16,474)	$ (7,963)
Adjustments to reconcile net loss to net cash from operating activities:
Depreciation		60	700	445
Depreciation and amortization included in cost of revenue		72	4,873	2,567
Amortization of intangible assets		378	10,535	4,227
Loss on disposal of property, plant and equipment		0	307	214
Loss on extinguishment of debt		0	2,031	0
Gain on PPP Forgiveness		0	(1,624)	0
Foreign currency translation adjustment		0	113	(68)
Bad debt expense		0	373	223
Share-based compensation		139	2,649	34
Deferred Taxes		(3)	0	0
Non-Controlling Interest		(968)	0	0
Change in fair value of Fathom earnout shares liability		(23,860)	(3,550)	1,055
Change in fair value of Sponsor earnout shares liability		(3,400)	0	0
Change in fair value of tax receivable agreement		300	0	0
Change in fair value of Warrant liability		(8,200)	0	0
Amortization of debt financing costs		16	3,126	205
Changes in operating assets and liabilities that provided cash:
Accounts receivable		(356)	(5,404)	1,063
Inventory		(340)	(961)	(356)
Prepaid expenses and other assets		1,249	(2,937)	(653)
Accounts payable		(100)	9,541	595
Accrued liabilities and other		1,096	3,925	282
Net cash provided by operating activities		521	7,223	1,870
Cash Flows from Investing Activities
Purchase of property and equipment		0	(8,972)	(1,626)
Cash used for acquisitions, net of cash acquired		0	(67,428)	(94,412)
Net cash used in investing activities		0	(76,400)	(96,038)
Cash Flows from Financing Activities
Proceeds from debt		0	183,500	65,124
Payments on debt		0	(104,091)	(1,679)
Proceeds from term loan and revolver		0	0	0
Payment of debt issuance costs		0	(3,259)	(1,207)
Proceeds from issuance of members' units		0	0	40,445
Distributions to unitholders		0	0	0
Cash paid for contingent consideration		0	(5,584)	(1,353)
Net cash provided by financing activities		0	70,566	101,330
Net increase in cash		521	1,389	7,162
Cash, beginning of period		9,577	8,188	1,026
Cash, end of period		20,357	9,577	8,188
Supplemental Cash Flows Information:
Cash paid for interest		700	9,436	3,491
Cash paid for taxes		0	62	11
Cash paid to related parties (Note 17)		700	11,252	6,879
Significant non-cash transactions:
Issuance of member interests for acquisitions		0	0	2,941
Initial recognition of contingent consideration for acquisitions		$ 0	$ 1,295	$ 11,737
[1]	See accompanying notes to the consolidated financial statements.

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	Note 1 - Nature of Business Fathom Digital Manufacturing Corporation (“Fathom” or, the “Company”) was incorporated as a Delaware corporation on December 23, 2021. Fathom was previously named Altimar Acquisition Corp. II ("Altimar II") before deregistering as an exempted company in the Cayman Islands. Fathom, through its consolidated subsidiary, Fathom Holdco, LLC (“Fathom OpCo”), is a leading on-demand digital manufacturing platform in North America, providing comprehensive product development and manufacturing services to many of the largest and most innovative companies in the world. Fathom OpCo was formed on April 16, 2021 as a limited liability company in accordance with the provisions of the Delaware Limited Liability Company Act, for the purpose of holding a 100 percent equity interest in MCT Group Holdings, LLC and its subsidiaries (“MCT Holdings”) and holding a 100 percent equity interest in Incodema Holdings, LLC and its subsidiaries (“Incodema Holdings”).

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	Note 2 - Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements comprise the financial statements of Fathom and its controlled subsidiaries for the nine-day period from December 23, 2021 to December 31, 2021 (the "2021 Successor Period"), the financial statements of Fathom OpCo and its controlled subsidiaries for the period from January 1, 2021 to December 22, 2021 (the "2021 Predecessor Period"), and the financial statements of Fathom OpCo and its controlled subsidiaries for the period from January 1, 2020 to December 31, 2020 (the "2020 Predecessor Period" and, collectively with the 2021 Predecessor Period, the "Predecessor Periods"). The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the accounting and disclosure rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). The consolidated balance sheet as of December 31, 2020 (Predecessor) and the consolidated statement of comprehensive loss for the 2020 Predecessor Period comprise the consolidated financial statements of Fathom OpCo for the same periods which were previously filed within the Company's registration statements files with the SEC, with certain reclassifications on the consolidated balance sheet and consolidated statement of comprehensive loss that were made such that the financial captions between the Successor Period and the Predecessor Periods are comparable. Amounts in the prior years' consolidated financial statements are reclassified whenever necessary to conform to the current year's presentation. The reclassifications had no impact on our results of operations, financial position, or cash flows for the Predecessor Periods. All material intercompany balances have been eliminated in consolidation in each period presented. Correction of Immaterial Errors The consolidated financial statements as of and for the 2020 Predecessor Period include the correction of an immaterial error. The correction relates to the misclassification of selling, general, and administrative expense as other expense on the consolidated statement of comprehensive loss for the 2020 Predecessor Period. The correction resulted in an increase to selling, general, and administrative expense of $ 2,511 and a decrease to other expense of $ 2,511 for the 2020 Predecessor Period. The comprehensive loss for the 2020 Predecessor Period was not impacted as a result of the correction of this immaterial error. In addition, the consolidated financial statements as of and for the 2021 Predecessor period include the correction of an immaterial error. The correction relates to the understatement of stock compensation expense in periods prior to the 2021 Predecessor Period. A correcting entry of $ 512 was recorded in the 2021 Predecessor Period statement of comprehensive loss as a prospective correction of the prior period immaterial errors. Principles of Consolidation The consolidated financial statements include the accounts of the Company, its controlled subsidiaries, and certain variable interest entities (“VIEs”) where the Company is the primary beneficiary. The Company is deemed to be the primary beneficiary of a VIE when it has both (1) the power to direct the activities of the VIE that most significantly impact the entity’s economic performance, and (2) exposure to benefits and/or losses that could potentially be significant to the entity. Assets and liabilities of VIEs and their respective results of operations are consolidated from the date that the Company became the primary beneficiary through the date that the Company ceases to be the primary beneficiary. Fathom consolidates the accounts of Fathom OpCo since Fathom OpCo has been determined to be a VIE and Fathom is the primary beneficiary of Fathom OpCo. Business Combination The Company applies the acquisition method to all transactions and other events in which the entity obtains control over one or more other businesses, including the Business Combination, (as defined in Note 3), whereby Fathom was determined to be the primary beneficiary of Fathom OpCo, a VIE. Assets acquired and liabilities assumed are measured at fair value as of the acquisition date. Liabilities related to contingent consideration are recognized at the acquisition date and re-measured at fair value in each subsequent reporting period if the contingent consideration is liability classified. Goodwill is recognized as the excess of the consideration transferred over the fair value of the net identifiable assets acquired. Under Accounting Standards Codification ("ASC") Topic 805 - Business Combinations ("ASC 805"), there is an option to apply push-down accounting, which establishes a new basis for the assets and liabilities of the acquired company based on a “push-down” of the acquirer’s stepped-up basis. The push-down accounting election is made in the reporting period in which the change in control event occurs. Fathom has elected push-down accounting for the Business Combination, and recorded the push-down entries at Fathom OpCo. Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Making estimates requires the Company’s management to exercise significant judgment. It is at least reasonably possible that the estimate of the effect of a condition, situation or set of circumstances that existed at the date of the consolidated financial statements, which the Company’s management considered in formulating its estimate, could change in the near term due to one or more future confirming events. Accordingly, the actual results could differ significantly from those estimates. Income Taxes The Company accounts for income taxes under ASC Topic 740 - Income Taxes ("ASC 740"), which prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities. The Company is organized as a Delaware C corporation. Credit Risk, Major Customers, and Suppliers The Company extends trade credit to its customers on terms that are generally practiced in the industry. During the 2020 Predecessor Period, the 2021 Predecessor Period, and 2021 Successor Period the Company did not have any customers or suppliers that comprised a significant percentage of the Company’s operations. Trade Accounts Receivable, Unbilled Revenue and Allowance for Doubtful Accounts Accounts receivable are stated at net invoice amounts. Unbilled revenue represents receivables due from customers as either the performance obligation has been completed for revenue recognized over time or the product has shipped and the customer invoice has yet to be generated. The balance in unbilled revenue, included in accounts receivable, was $ 0 and $ 173 as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor), respectively. An allowance for doubtful accounts is established based on a specific assessment of all invoices that remain unpaid following normal customer payment periods. In addition, a general valuation allowance is established for the remaining accounts receivable that have not been specifically assessed based on historical loss experience as well as geographic and general economic conditions. All amounts deemed to be uncollectible are charged against the allowance for doubtful accounts in the period that determination is made. The allowance for doubtful accounts on accounts receivable balances was $ 1,150 as of December 31, 2021 (Successor) and $ 649 as of December 31, 2020 (Predecessor). Inventory Inventory is stated at the lower of cost or net realizable value (“NRV”), with NRV based on selling prices in the ordinary course of business, less costs of completion, disposal, and transportation. Costs are determined on the first-in, first-out (“FIFO”) method. Property and Equipment Property and equipment are recorded at cost less accumulated depreciation and amortization. The straight-line method is used for computing depreciation. Assets are depreciated over their estimated useful lives. The cost of leasehold improvements are amortized over the lesser of the length of the related leases or the estimated useful lives of the assets. Costs of maintenance and repairs are charged to expense when incurred. See Note 7 for further information. Goodwill The Company recognizes goodwill in accordance with ASC Topic 350, Goodwill and Other ("ASC 350"). Goodwill is the excess of costs of an acquired entity over the amounts assigned to assets acquired and liabilities assumed in a business combination. Goodwill is not amortized. During the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period the Company determined that no impairment charges for goodwill were required to be recognized. Intangible Assets Acquired intangible assets subject to amortization are stated at cost and are amortized using the straight-line method over the estimated useful lives of the assets. Intangible assets that are subject to amortization are reviewed for potential impairment whenever events or circumstances indicate that carrying amounts may not be recoverable. During the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, there were no impairments of intangible assets. New Fathom Units In conjunction with the Business Combination, Fathom OpCo restructured its classes of members units whereby, subsequent to the Business Combination, Fathom OpCo's equity consists solely of Class A common units (the "New Fathom Units"). Prior to the Business Combination, Fathom OpCo's members' equity consisted of Class A common units and Class B common units. See Note 14 for further information. Warrant Liability The Company accounts for both the Public Warrants (the "Public Warrants") and Private Placement Warrants (the "Private Placement Warrants") (collectively as the "Warrants") as liability-classified instruments based on an assessment of the Warrants’ specific terms and applicable authoritative guidance per ASC Topic 480, Distinguishing Liabilities from Equity ("ASC 480") and ASC Topic 815, Derivatives and Hedging ("ASC 815"). The assessment considers whether the Warrants are freestanding financial instruments pursuant to ASC 480, whether Warrants meet the definition of a liability pursuant to ASC Topic 480 and whether the Warrants meet all of the requirements for equity classification under ASC 815, including whether the Warrants are indexed to the Company's Class A common stock. This assessment, which requires the use of professional judgment, is conducted at the time of issuance of the Warrants and as of each subsequent quarterly period end date while the Warrants are outstanding. Since both the Public Warrants and Private Placement Warrants are liability-classified, the Warrants are required to be recorded at fair value on the date of issuance and each balance sheet date thereafter. Changes in the fair value of the Warrants are recognized as a non-cash gain or loss on the consolidated statement of comprehensive income (loss). The fair value of the Public Warrants was determined using the closing price of the Public Warrants as of December 31, 2021 (Successor), and the fair value of the Private Placement Warrants was estimated using a Monte Carlo simulation approach. See Note 11 and Note 19 for further information. Fathom Earnout Shares The Company issued 9,000,000 shares of Class A common stock and New Fathom Units that are subject to certain vesting and transfer restrictions (collectively, the "Fathom Earnout Shares") as part of the Business Combination. The Fathom Earnout Shares vest in three tranches of 3,000,000 shares. The first tranche of the Fathom Earnout Shares vest if the volume weighted average price (“VWAP”) of the Company's Class A common stock with respect to a trading day is greater than or equal to $ 12.50 for any 20 trading days within a consecutive 30 -trading-day period. The second tranche of Fathom Earnout Shares vest if the VWAP of the Company's Class A common stock with respect to a trading day is greater than or equal to $ 15.00 for any 20 trading days within a consecutive 30 -trading-day period. The third tranche of Fathom Earnout Shares vest if the VWAP of the Company's Class A common stock with respect to a trading day is greater than or equal to $ 20.00 for any 20 trading days within a consecutive 30 -trading-day period. The Fathom Earnout Shares were issued as part of the Business Combination and are accounted for as contingent consideration, and thus purchase consideration, and classified as a liability. This classification requires the Company to re-measure the Fathom Earnout Shares at fair value each reporting date. See Note 3 for further information. Sponsor Earnout Shares Prior to Altimar II's initial public offering, Altimar II Sponsor, LLC (the "Sponsor") received 8,625,000 Class B Ordinary Shares ("Founder Shares") of the Company in exchange for an investment of $ 25 . In conjunction with the Business Combination, the holders of the Founder Shares forfeited 2,587,500 Founder Shares and received 1,267,500 shares of Class A common stock, (the "Sponsor Earnout Shares" and, together with the Fathom Earnout Shares, the "Earnout Shares") which vest only if the stock price of the Company reaches $ 12.50 for any 20 days within a consecutive 30 -trading-day period. The remaining 4,770,000 Founder Shares were cancelled and replaced with 4,770,000 shares of Class A common stock of the Company which are recorded as equity in the Company's consolidated balance sheet as of December 31, 2021 (Successor) The Company classifies the Sponsor Earnout Shares as a liability measured at fair value upon the consummation of the Business Combination, the date of issuance, and each subsequent reporting date. The Sponsor Earnout Shares are not included as part of the consideration transferred in the Business Combination since the Sponsor Earnout Shares do not represent payments to any of the sellers in the Business Combination. Non-controlling Interest Non-controlling interest represents the Company’s non-controlling interest in consolidated subsidiaries which are not attributable, directly or indirectly, to the controlling Class A common stock ownership of the Company. The Company's comprehensive income in the 2021 Successor Period is reduced by the portion of Fathom OpCo's comprehensive loss that is attributable to noncontrolling interests. The Company's non-controlling interest is representative of the fact that the Company directly owns 37.6 % of Fathom OpCo's New Fathom Units while the holders of the non-controlling interest in Fathom OpCo hold 62.4 %. Since the non-controlling interest may be redeemed for cash and redemption is considered outside of the Company's control, the non-controlling interest is recorded in temporary or "mezzanine" equity on the Consolidated Balance sheet as of December 31, 2021 (Successor). See Note 3 and Note 14 for further information. Tax Receivable Agreement In connection with the Business Combination, Fathom entered into the Tax Receivable Agreement ("TRA"), which generally provides for the payment by it of 85 % of the net cash savings, if any, in U.S. federal, state and local, income and franchise tax (computed using certain assumptions to address the impact of state and local taxes) that it actually realizes (or in certain cases is deemed to realize) as a result of tax basis in certain assets and other tax attributes. The TRA is a direct obligation of the Company, and not of its subsidiaries. Since the payments under the TRA will be made to selling shareholders of Fathom OpCo, the fair value of the TRA as of the date of the Business Combination is considered part of the consideration transferred as part of the Business Combination with Fathom OpCo. See Note 3 for further information. Subsequent to the initial recognition of the TRA as part of the Business Combination on December 23, 2021, the TRA is recorded at fair value. Any changes in fair value of the TRA subsequent to the Business Combination are recorded as non-cash gains or losses in the Company consolidated statement of comprehensive loss in the 2021 Successor Period. See Note 19 for further information. Foreign Currency Exchange and Translation The expression of assets and liabilities in a foreign currency amount gives rise to exchange gains and losses when such obligations are paid in U.S. dollars. Foreign currency exchange rate adjustment (i.e., differences between amounts recorded and actual amounts owed or paid) are reported in the consolidated statements of comprehensive income (loss) as foreign currency fluctuations occur. Foreign currency exchange rate adjustments are reported in the consolidated statements of cash flows using the exchange rates in effect at the time of the cash flows. Assets and liabilities of the Company's operations in China are translated into U.S. dollars at the rate of exchange in effect at the close of the period. Income and expenses are translated at an average rate of exchange for the period. The aggregate effect of translating the financial statements is included in other comprehensive loss. Adjustments to the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period were immaterial. Fair Value Measurements The fair value of the Company’s assets and liabilities, which qualify as financial instruments under ASC Topic 820, Fair Value Measurement ("ASC 820"), approximates the carrying amounts represented in the accompanying consolidated balance sheets, primarily due to their short-term nature, except for the Earnout Shares liability and Warrant liabilities, see Note 19 for further information . The framework for determining fair value is based on a hierarchy that prioritizes the inputs and valuation techniques used to measure fair value. There are three levels of inputs that may be used to measure fair value: Fair values determined by Level 1 inputs use quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. Fair values determined by Level 2 inputs use other inputs that are observable, either directly or indirectly. These Level 2 inputs include quoted prices for similar assets and liabilities in active markets and other inputs such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs, including inputs that are available in situations where there is little, if any, market activity for the related asset. These Level 3 fair value measurements are based primarily on management’s own estimates using pricing models, discounted cash flow methodologies, or similar techniques considering the characteristics of the asset. In instances whereby, inputs used to measure fair value fall into different levels in the above fair value hierarchy, fair value measurements in their entirety are categorized based on the lowest level input that is significant to the valuation. The Company’s assessment of the significance of particular inputs to these fair value measurements requires judgment and considers factors specific to each asset or liability. Debt Issuance Costs Debt issuance costs were incurred by Fathom OpCo in connection with obtaining the debt to finance the acquisitions disclosed in Note 4. If such financing is settled or replaced prior to maturity with debt instruments that have substantially different terms, the settlement is treated as an extinguishment and the unamortized costs are charged to gain or loss on extinguishment of debt. If such financing is settled or replaced with debt instruments from the same lender that do not have substantially different terms, the new debt agreement is accounted for as a modification of the prior debt agreement and the unamortized costs remain capitalized, the new original issuance discount costs are capitalized, and any new third-party costs are charged to expense. These costs are recorded as a reduction in the recorded balance of the outstanding debt. The costs are amortized over the term of the related debt and reported as a component of interest expense by using the straight-line method which is not materially different than the effective interest method. Revenue Recognition The Company accounts for revenue under ASC Topic 606, Revenue from Contracts with Customer's ("ASC 606"). Most of the Company’s revenue has one performance obligation and is recognized on a point-in-time basis upon shipment. The majority of the Company’s injection molding contracts have multiple performance obligations including one obligation to produce the mold and sample part and a second obligation to produce production parts. For injection molding contracts with multiple performance obligations, the Company allocates revenue to each performance obligation based on its relative standalone selling price and recognizes revenue for each performance obligation on a point-in-time basis upon shipment. We generally determine stand-alone selling price based on the price charged to customers. The Company’s payments terms are consistent with industry standards and never exceed 12 months. Segment Reporting In accordance with the Financial Accounting Standards Board's ("FASB") authoritative guidance on segment reporting, the Company has one operating segment and one reportable segment. The Company has one line of business, which is product development and on-demand manufacturing services. Other Comprehensive Loss U.S. GAAP generally requires that recognized revenue, expenses, gains and losses be included in net income. Certain changes in assets and liabilities, however, such as foreign currency translation adjustments, are reported as a direct adjustment to the equity section of the consolidated balance sheets. Such items, along with net income, are considered components of comprehensive income or loss. Recent Accounting Pronouncements The FASB issued Accounting Standards Update (“ASU”) 2016-02 which is codified in ASC 842, Leases ("ASC 842") and will supersede the current lease requirements in ASC 840 ("ASC 840"). ASC 842 requires lessees to recognize a right-to-use asset and related lease liability for all leases, with a limited exception for short-term leases. Leases will be classified as either finance or operating, with the classification affecting the pattern of expense recognition in the statement of operations. Currently, leases are classified as either capital or operating, with only capital leases recognized on the balance sheet. The new lease guidance will be effective for the Company’s fiscal year ending December 31, 2022 and will be applied using a modified retrospective transition method to either the beginning of the earliest period presented or the beginning of the year of adoption. The new lease standard is expected to have a significant effect on the Company’s financial statements as a result of the Company’s operating leases, that will be reported on the balance sheet at adoption. Upon adoption, the Company will recognize a lease liability and corresponding right-to use asset based on the present value of the minimum lease payments. The effects on the results of operations are not expected to be significant as recognition and measurement of expenses and cash flows for leases will be substantially the same under the new standard. The FASB issued ASU 2016-13, Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments ("ASC 326"), which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments including trade receivables and available for sale debt securities. ASC 326 is effective for fiscal years beginning after December 15, 2022, with early adoption permitted. In August 2020, the FASB issued Accounting Standards Update No. 2020-06, Debt — Debt with Conversion and Other Options ("Subtopic 470-20") and Derivatives and Hedging — Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity” (“ASU 2020-06”), which simplifies accounting for convertible instruments by removing major separation models required under current GAAP. ASU 2020-06 removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception and it also simplifies the diluted earnings per share calculation in certain areas. ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years, with early adoption permitted. The Company adopted ASU 2020-06 effective as of January 1, 2021. The adoption of ASU 2020-06 did not have an impact on the Company’s financial statements as the Company did not hold convertible instruments prior to January 1, 2021. The Company’s management does not believe that any other recently issued, but not yet effective, accounting standards, if currently adopted, would have a material effect on the Company’s financial statements.

Business Combination with Fatho

Business Combination with Fathom OpCo	12 Months Ended
	Dec. 31, 2021
Business Acquisition [Line Items]
Business Combination with Fathom OpCo	Note 4 - Fathom OpCo Predecessor Period Acquisitions In the Predecessor Periods, Fathom OpCo completed a series of acquisitions that were each accounted for under the acquisition method in accordance with ASC 805. Acquisition of Incodema, LLC and Newchem, LLC Fathom OpCo completed acquisitions of Incodema, LLC (“Incodema”) and Newchem, LLC (“Newchem”) on July 27, 2020 in which it acquired 100 percent of the membership interests of Incodema and Newchem. Incodema is a prototype and short run sheet metal stamping provider, and Newchem is a photochemical milling company whose process involves coating material specified with a light sensitive polymer, imaging with a photo tool using UV light, developing and then chemically etching. The acquisition was consistent with Fathom OpCo's mission to expand its high-quality manufacturing and industrial technology capabilities in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Incodema Newchem Total Cash $ 30,948 $ 6,320 $ 37,268 Equity instruments 920 183 1,103 Contingent consideration 8,696 - 8,696 Fair value of total consideration transferred $ 40,564 $ 6,503 $ 47,067 The consideration excluded $ 1,489 of buyer transaction expenses that were included in other expenses within the 2020 Predecessor Period consolidated statements of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 400 to an affiliate of the majority member of Fathom OpCo in conjunction with the transaction. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Incodema and Newchem: Acquisition Date Fair Value Recognized amounts of identifiable assets acquired and liabilities assumed Incodema Newchem Cash $ 63 $ 69 Accounts receivable, net 2,370 741 Inventory 735 487 Other current assets 3 1 Prepaid expenses 77 8 Fixed assets, net 2,277 1,949 Intangible assets 19,300 2,800 Total assets acquired 24,825 6,055 Accounts payable 324 223 Accrued expenses 110 35 Other current liabilities 286 61 Total liabilities assumed 720 319 Total identifiable net assets 24,105 5,736 Goodwill $ 16,459 $ 767 Additional contingent consideration is due to the seller of Incodema based upon the gross profit of a specified product sold by Incodema for the periods en ding December 31, 2020 (Predecessor), December 31, 2021 (Successor), and December 31, 2022. The Company paid $ 1,984 in 2021 in contingent consideration for the period ended December 31, 2020 and expects that the remaining undiscounted payments under the under the contingent consideration arrangement will be $ 2,720 and $ 850 in the periods ended December 31, 2022, and December 31, 2023, respectively. Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value - Incodema Estimated Life (Years) Trade name $ 2,700 15 Customer relationships 11,500 9 Developed software 5,100 5 Total intangible assets $ 19,300 Acquisition Date Fair Value - Newchem Estimated Life (Years) Trade name $ 300 5 Customer relationships 2,500 16 Total intangible assets $ 2,800 The amounts of revenue and net (loss) of Incodema since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 6,900 Net (loss) $ ( 1,085 ) The amounts of revenue and net income of Newchem since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 2,369 Net income $ 184 Acquisition of Dahlquist Machine, LLC Fathom OpCo completed an acquisition of Dahlquist Machine, LLC (“Dahlquist”) on December 16, 2020 in which it acquired 100 percent of the membership interest of Dahlquist. In conjunction with the equity purchase, Fathom OpCo acquired the real estate in which Dahlquist Machine, LLC performs their operations. Dahlquist is a precision machining company with state-of-the-art computer numerical control ("CNC") mills and lathes, specializing in high-speed precision machining of light metals, aluminum, and plastics. The acquisition was consistent with Fathom OpCo's mission to acquire high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 16,098 Equity instruments 368 Contingent consideration 1,166 Fair value of total consideration transferred $ 17,632 The consideration excludes $ 804 of buyer transaction expenses that are included in other expenses within the 2020 Predecessor Period consolidated statements of comprehensive loss. In addition, Fathom Opco paid a transaction fee of $ 252 to an affiliate of the majority member of Fathom OpCo as part of the transaction. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Dahlquist: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 357 Accounts receivable, net 1,215 Inventory 1,597 Indemnification asset - PPP loan 518 Prepaid expenses 8 Fixed assets, net 3,753 Intangible assets 8,300 Total assets acquired 15,748 Accounts payable 68 Paycheck Protection Program (PPP) loan 518 Accrued expenses 475 Total liabilities assumed 1,061 Total identifiable net assets 14,687 Goodwill $ 2,945 The earnout is based upon the Dahlquist's reported earnings before interest, taxes, depreciation, and amortization for the trailing twelve-month period ending June 30, 2021. All contingent consideration balances related to the Dahlquist acquisition ($ 2,600 ) have been paid as of December 31, 2021 (Successor). Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 500 5 Customer relationships 7,800 14 Total intangible assets $ 8,300 The amounts of revenue and net (loss) of Dahlquist since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was a follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 310 Net (loss) $ ( 940 ) Acquisition of Majestic Metals, LLC Fathom OpCo completed an acquisition of Majestic Metals, LLC (“Majestic”) on December 17, 2020 in which it acquired 100 percent of the membership interest of Majestic. Majestic is a precision sheet metal fabricator and has evolved into one of the most progressive precision sheet metal products manufacturers in the nation. The acquisition is consistent with the Fathom OpCo's mission to expand its high-quality manufacturing and industrial technology capabilities in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 33,557 Equity instruments 1,471 Fair value of total consideration transferred $ 35,028 The consideration excludes $ 1,145 of buyer transaction expenses that are included in other expenses within the 2020 Predecessor Period consolidated statement of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 361 to an affiliate of the majority member of Fathom OpCo. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ ( 1 ) Accounts receivable, net 2,646 Inventory 1,184 Other current assets 30 Prepaid expenses 201 Fixed assets, net 4,229 Intangible assets 20,100 Total assets acquired 28,389 Accounts payable 244 Accrued expenses 231 Other current liabilities 644 Total liabilities assumed 1,119 Total identifiable net assets 27,270 Goodwill $ 7,758 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 1,500 5 Customer relationships 18,600 16 Total intangible assets $ 20,100 The amounts of revenue and net (loss) of Majestic since the acquisition date included in the 2020 Predecessor Period statement of comprehensive loss for the reporting periods are as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 911 Net (loss) $ ( 1,129 ) Acquisition of Summit Tooling, Inc., and Summit Plastics, LLC: Fathom OpCo completed an acquisition of Summit Tooling Inc. ("Summit Tooling") and Summit Plastics LLC (“Summit Plastics”, together with Summit Tooling, “Summit”) on February 1, 2021 in which it acquired 100 percent of the equity interests of Summit. In conjunction with the equity purchase, Fathom OpCo acquired the real estate in which Summit performs their operations. Summit Tooling designs and manufactures plastic injection molds and Summit Plastics provides molding of precision plastic components for a variety of industries. The primary reason for the acquisition was to expand Fathom OpCo's capabilities in manufacturing and expand its customer base of high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 10,875 Fair value of total consideration transferred $ 10,875 The consideration excluded $ 892 of buyer transaction expenses that are included in other expenses within the 2021 Predecessor Period consolidated statement of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 225 to an affiliate of the majority member of Fathom OpCo. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired business into Fathom OpCo's existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Summit: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 40 Accounts receivable, net 627 Inventory 339 Fixed assets, net 4,371 Intangible assets 5,000 Total assets acquired 10,377 Accounts payable 40 Deferred revenue 776 Other current liabilities 1,418 Total liabilities assumed 2,234 Total identifiable net assets 8,143 Goodwill $ 2,732 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 400 5 Customer relationships 4,600 11 Total intangible assets $ 5,000 The amounts of revenue and net loss of Summit since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Predecessor Period are as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 6,748 Net (loss) $ ( 370 ) Acquisition of Precision Process Corp.: Fathom OpCo completed an acquisition of Precision Process Corp. ("PPC") on April 30, 2021 in which it acquired 100 percent of the membership interest of PPC. In conjunction with the equity purchase, Fathom Opco acquired the real estate in which PPC performs their operations. PPC is a manufacturing company that offers integrated engineering-to-production services, specializing in making prototype, small-run and mass production of parts and components for medical, high-tech, automotive and metal stamping industries. The primary reason for the acquisition was to expand Fathom OpCo's capabilities into metal stamping with high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 25,721 Fair value of total consideration transferred $ 25,721 The consideration excludes $ 984 of buyer transaction expenses that are included in other expenses within the accompanying consolidated statements of comprehensive loss . Fathom OpCo paid a transaction fee of $ 264 to an affiliate of the majority member of Fathom OpCo. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired business into Fathom OpCo's existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of PPC: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 162 Accounts receivable, net 899 Inventory 480 Fixed assets, net 2,413 Intangible assets 14,200 Total assets acquired 18,154 Accounts payable 148 Accrued expenses 79 Total liabilities assumed 227 Total identifiable net assets 17,927 Goodwill $ 7,794 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 1,100 5 Customer relationships 13,100 17 Total intangible assets $ 14,200 The amounts of revenue and net loss of PPC since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Successor Period is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 6,993 Net (loss) $ ( 34 ) Acquisition of Centex Machine and Welding, Inc. and Laser Manufacturing, Inc.: Fathom OpCo completed acquisitions of Centex Machine and Welding, Inc. ("Centex") and Laser Manufacturing, Inc. ("Laser") on April 30, 2021 in which it acquired 100 percent of the equity interests of Centex and Laser. Centex is a top tier medical device manufacturing supplier and Laser provides high precision manufacturing services, combining state of the art technology with expert craftsmanship to deliver superior products. The acquisition was completed in order to expand Fathom OpCo's high-quality manufacturing and industrial technology capabilities in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Centex Laser Total Cash $ 11,774 $ 6,946 $ 18,720 Fair value of total consideration transferred $ 11,774 $ 6,946 $ 18,720 The consideration excluded $ 1,226 of buyer transaction expenses that are included in other expenses within the 2021 Predecessor period consolidated statements of comprehensive loss . Fathom OpCo also paid a transaction fee of $ 190 to an affiliate of the majority member of the Fathom OpCo in connection with the transaction. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired businesses into the Company’s existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Centex and Laser: Acquisition Date Fair Value Centex Laser Recognized amounts of identifiable assets acquired and liabilities assumed Cash $ - $ 68 Accounts receivable, net 1,775 900 Inventory 524 622 Prepaid expenses 108 1 Fixed assets, net 1,787 760 Intangible assets 6,243 3,557 Other assets 1 2 Total assets acquired 10,438 5,910 Accounts payable 252 568 Paycheck Protection Program (PPP) loan 649 - Accrued expenses 271 27 Other current liabilities 23 44 Other noncurrent liabilities 1,234 703 Total liabilities assumed 2,429 1,342 Total identifiable net assets 8,009 4,568 Goodwill $ 3,765 $ 2,378 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Estimated Life (Years) Trade name $ 510 5 Customer relationships 5,733 17 Total intangible assets $ 6,243 Acquisition Date Estimated Life (Years) Trade name $ 290 5 Customer relationships 3,267 17 Total intangible assets $ 3,557 The amounts of revenue and net loss of Centex and Laser since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Predecessor Period and is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 9,642 Net (loss) $ ( 98 ) Acquisition of Sureshot Precision, LLC: Fathom OpCo completed an acquisition of Sureshot Precision, LLC (d/b/a as "Micropulse West") on April 30, 2021 in which it acquired 100 percent of the membership interest of Micropulse West. Micropulse West is a full-service specialist offering a variety of services such as wire Electrical Discharge Machine (“EDM”), ram EDM, small hole EDM, CNC and manual machining/turning, surface grinding, and inspection. The acquisition was consistent with the Fathom OpCo’s mission to acquire high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 12,452 Contingent consideration 1,295 Fair value of total consideration transferred $ 13,747 The consideration excludes $ 869 of buyer transaction expenses that are included in other expenses within the 2021 Predecessor Period consolidated statement of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 130 to an affiliate of the majority member of Fathom OpCo. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired businesses into Fathom OpCo's existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Micropulse West: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 70 Accounts receivable, net 866 Inventory 333 Other current assets 10 Fixed assets, net 2,490 Intangible assets 7,000 Total assets acquired 10,769 Accounts payable 139 Accrued expenses 13 Other current liabilities 99 Total liabilities assumed 251 Total identifiable net assets 10,518 Goodwill $ 3,229 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 600 5 Customer relationships 6,400 17 Total intangible assets $ 7,000 The amounts of revenue and net loss of Micropulse West since the acquisition date included in the 2021 Predecessor Period consolidated statement of comprehensive loss is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 4,614 Net (loss) $ ( 115 ) Other acquisitions Fathom OpCo acquired substantially all assets and property, and agreed to assume certain liabilities of GPI Prototype & Manufacturing Services, LLC on August 18, 2020 for a total consideration transferred of $ 2,441 . The primary reason for the acquisition was to expand Fathom OpCo's capabilities in 3D printing as well as expand its customer based with high-quality manufacturing and industrial technology companies in North America. In addition, Fathom OpCo completed an acquisition of Mark Two Engineering, LLC (“Mark Two”) on December 18, 2020 in which it acquired 100 percent of the membership interest of Mark Two for a total consideration transferred of $ 6,639 . Mark Two is a contract manufacturing firm that specializes in rapid prototyping, complex high-precision component machining and manufacturing in the Medical Device and Aerospace industries. The acquisition is consistent with Fathom Opco's mission to expand its high-quality manufacturing and industrial technology capabilities in North America.
Fathom OpCo
Business Acquisition [Line Items]
Business Combination with Fathom OpCo	Note 3 - Business Combination with Fathom OpCo On December 23, 2021 , Altimar II and Fathom OpCo closed a series of transactions (collectively, the "Business Combination") pursuant to the Business Combination Agreement dated as of July 15, 2021, as amended (the "Agreement"), that resulted in the combined Company becoming a publicly-traded company on the New York Stock Exchange ("NYSE") with the Company controlling Fathom OpCo in an "UP-C" structure. At the closing on December 23, 2021, Altimar II domesticated into a Delaware corporation, and the Company, Fathom Digital Manufacturing Corporation, was formed. Following the closing, the public investors, the PIPE Investors and the Founders collectively held Class A common stock representing approximately 10.4 % economic interest in Fathom OpCo, and the CORE Investors and the other Legacy Fathom Owners collectively held 89.6 % of economic interest in Fathom OpCo in the form of Class A common stock. Additionally, the Company issued to the legacy Fathom owners shares of Class B common stock, which have no economic rights but entitle each holder to voting power ( one vote per share). Subsequently to the closing, the Company controls Fathom OpCo and is a holding company with no assets or operations other than its equity interest in Fathom OpCo. The Business Combination was accounted for using the acquisition method with the Company as the accounting acquirer. Under the acquisition method of accounting, the Company's assets and liabilities were recorded at carrying value, and the assets and liabilities associated with Fathom OpCo were recorded at estimated fair value as of the closing date. The excess of the purchase price over the estimated fair values of the net assets acquired was recognized as goodwill. For accounting purposes, the acquirer is the entity that has obtained control of another entity and, thus, consummated a business combination. The determination of whether control has been obtained begins with the evaluation of whether control should be evaluated based on the variable interest or the voting interest model. If the acquiree is a variable interest entity, the primary beneficiary would be the accounting acquirer. Fathom OpCo met the definition of a variable interest entity, and the Company was determined to the be the primary beneficiary and is therefore also the accounting acquirer in the Business Combination. See Note 2 and Note 22 for further information. As a result of the Business Combination, the Company's financial statement presentation distinguishes Fathom OpCo as the "Predecessor" through the closing date. The Company is the "Successor" for periods after the closing date of December 22, 2021. Revenue and earnings from the date of the Business Combination to year-end are shown as the "Successor" period on the consolidated statement of comprehensive income (loss). As a result of the application of the acquisition method of accounting in the Successor period, the consolidated financial statements for the Successor period are presented on a full step-up basis, and are therefore not comparable to the consolidated financial statements of the Predecessor period that are not presented on the same full step-up basis. In connection with the Business Combination, the Company incurred $ 19,010 of transaction expenses. These costs were recorded on the income statement of Altimar II prior to the Business Combination. Since the Predecessor period for purposes of these financial statements was deemed to be the historical results of Fathom OpCo, these transaction costs are not presented in either the Company's consolidated statement of comprehensive income (loss) for the 2021 Predecessor Period or the consolidated statement of comprehensive income (loss) for the 2020 Predecessor Period. However, these transaction costs are reflected in the accumulated deficit balance of the Company in the consolidated balance sheet as of December 31, 2021 (Successor). Also, in connection with the Business Combination, Fathom OpCo incurred $ 27,397 of transaction expenses. $ 14,882 of this amount represented contingent fees and success fees which would not have been incurred had the Business Combination not closed. The Company has therefore elected an accounting policy to present these transaction costs "on-the-line" whereby the transaction costs are not recorded in either the 2021 Predecessor Period or the 2020 Predecessor Period of Fathom OpCo or the 2021 Successor Period of the Company. The remaining $ 12,515 of transaction expenses were not contingent on the closing of the Business Combination and therefore have been reflected as period costs in the consolidated statement of comprehensive income (loss) for the 2021 Predecessor Period. The seller earnout contingent consideration below represents the estimated fair market value of the 9,000,000 Fathom Earnout Shares issued in conjunction with the Business Combination. The Fathom Earnout Shares will be settled with shares of Class A common stock or New Fathom Units and is accounted for as liability classified contingent consideration. The Fathom Earnout Shares vest in three equal tranches of 3,000,000 shares each at the volume-weighted average share price thresholds of $ 12.50 , $ 15.00 and $ 20.00 , respectively. The earnout period related to the Fathom Earnout Shares is five years from the date of the closing of the Business Combination. These estimated fair values are preliminary and subject to adjustment in subsequent periods. In conjunction with the Business Combination, the Company recognized a deferred tax liability $ 17,573 . The deferred tax liability was recorded on the standalone books of the Company with an offset to goodwill. The deferred tax liability is included in the other long-term liabilities caption in the table below. See Note 21 for further information. The Business Combination was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred was $ 1,364,220 . See below for a summary of the total consideration transferred. Total Consideration Transferred: Total cash consideration $ 53,332 Fathom earnout shares 88,160 Class A common stock transferred 375,478 TRA obligations to the sellers 4,300 Total consideration transferred to sellers 521,270 Non-controlling interest 842,950 Fair value of total consideration transferred $ 1,364,220 The following table sets forth the fair value of the assets acquired and liabilities assumed in connection with the acquisition: Total Assets acquired: Cash and cash equivalents $ 9,577 Accounts receivable, net 25,010 Inventory 12,825 Prepaid expenses 2,336 Other current assets 836 Property and equipment, net 44,397 Goodwill 1,189,464 Intangible assets 270,000 Other assets 2,200 Total assets acquired 1,556,645 Liabilities assumed: Accounts payable 9,808 Taxes payable 71 Accrued expenses 4,860 Current portion - long-term debt 152,000 Deferred revenue 651 Other current liabilities 4,504 Other long-term liabilities 20,531 Total liabilities assumed 192,425 Net identifiable assets acquired $ 1,364,220 The purchase price allocation is preliminary and subject to change during the measurement period, which is not to exceed one year from the acquisition date. At this time, the Company does not expect material changes to the assets acquired or liabilities assumed. Goodwill represents future economic benefits arising from acquiring Fathom OpCo's equity, primarily due to its strong market position and its assembled workforce that are not individually and separately recognized as intangible assets. A portion of the Goodwill is deductible for tax purposes. Goodwill is allocated to the Company's sole reportable segment and reporting unit. Identifiable Intangible Assets Provisional fair value Provisional useful life (in years) Trade name $ 70,000 15 Customer relationships 180,000 19 Developed software 4,300 5 Developed technology 15,700 5 $ 270,000 The weighted average amortization period for the amortizable intangibles assets is 16.9 years. The following table present unaudited pro forma as if the acquisition of Fathom OpCo had occurred on January 1, 2020 and for the years ended December 31, 2021 and December 31, 2020 respectively, after giving effects to certain adjustments. The unaudited pro forma financial information is not necessarily indicative of the results of operations that would have occurred had the acquisition been affected on January 1, 2020. In addition, these results are not intended to be a projection of future results and do not reflect events that may occur after the acquisition, including but not limited to revenue enhancements, cost savings or operating synergies that the combined entity may achieve as a result of the acquisition. The Company determined that the 2021 Successor Period was immaterial and therefore, not broken-out separately below. Pro Forma Information (Unaudited) Year Ended December 31, 2021 2020 Pro forma revenue $ 162,563 $ 149,405 Pro forma net (loss) ( 14,088 ) ( 17,939 ) Pro forma net (loss) attributable to controlling interest ( 5,297 ) ( 6,745 ) Pro forma net (loss) attributable to non-controlling interest $ ( 8,791 ) $ ( 11,194 ) The supplemental and unaudited pro forma net (loss) includes the following adjustments: • Adjustments to amortization of inventory step-up for the years ended December 31, 2021 and December 31, 2020 of $ 0 and $ 2,626 , respectively; • Adjustment to depreciation and amortization for the years ended December 31, 2021 and December 31, 2020 of $ 25,759 and $ 19,325 , respectively; • Adjustment to interest expense for the years ended December 31, 2021 and December 31, 2020 of ($ 6,766 ) and $ 1,379 , respectively; • Adjustment to stock-based compensation expense for the years ended December 31, 2021 and December 31, 2020 of ($ 1,595 ) and $ 1,595 , respectively; and • Adjustment to transaction-related costs for the years ended December 31, 2021 and December 31, 2020 of ($ 7,984 ) and $ 7,984 , respectively.

Fathom OpCo Predecessor Period

Fathom OpCo Predecessor Period Acquisitions	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Fathom OpCo Predecessor Period Acquisitions	Note 4 - Fathom OpCo Predecessor Period Acquisitions In the Predecessor Periods, Fathom OpCo completed a series of acquisitions that were each accounted for under the acquisition method in accordance with ASC 805. Acquisition of Incodema, LLC and Newchem, LLC Fathom OpCo completed acquisitions of Incodema, LLC (“Incodema”) and Newchem, LLC (“Newchem”) on July 27, 2020 in which it acquired 100 percent of the membership interests of Incodema and Newchem. Incodema is a prototype and short run sheet metal stamping provider, and Newchem is a photochemical milling company whose process involves coating material specified with a light sensitive polymer, imaging with a photo tool using UV light, developing and then chemically etching. The acquisition was consistent with Fathom OpCo's mission to expand its high-quality manufacturing and industrial technology capabilities in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Incodema Newchem Total Cash $ 30,948 $ 6,320 $ 37,268 Equity instruments 920 183 1,103 Contingent consideration 8,696 - 8,696 Fair value of total consideration transferred $ 40,564 $ 6,503 $ 47,067 The consideration excluded $ 1,489 of buyer transaction expenses that were included in other expenses within the 2020 Predecessor Period consolidated statements of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 400 to an affiliate of the majority member of Fathom OpCo in conjunction with the transaction. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Incodema and Newchem: Acquisition Date Fair Value Recognized amounts of identifiable assets acquired and liabilities assumed Incodema Newchem Cash $ 63 $ 69 Accounts receivable, net 2,370 741 Inventory 735 487 Other current assets 3 1 Prepaid expenses 77 8 Fixed assets, net 2,277 1,949 Intangible assets 19,300 2,800 Total assets acquired 24,825 6,055 Accounts payable 324 223 Accrued expenses 110 35 Other current liabilities 286 61 Total liabilities assumed 720 319 Total identifiable net assets 24,105 5,736 Goodwill $ 16,459 $ 767 Additional contingent consideration is due to the seller of Incodema based upon the gross profit of a specified product sold by Incodema for the periods en ding December 31, 2020 (Predecessor), December 31, 2021 (Successor), and December 31, 2022. The Company paid $ 1,984 in 2021 in contingent consideration for the period ended December 31, 2020 and expects that the remaining undiscounted payments under the under the contingent consideration arrangement will be $ 2,720 and $ 850 in the periods ended December 31, 2022, and December 31, 2023, respectively. Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value - Incodema Estimated Life (Years) Trade name $ 2,700 15 Customer relationships 11,500 9 Developed software 5,100 5 Total intangible assets $ 19,300 Acquisition Date Fair Value - Newchem Estimated Life (Years) Trade name $ 300 5 Customer relationships 2,500 16 Total intangible assets $ 2,800 The amounts of revenue and net (loss) of Incodema since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 6,900 Net (loss) $ ( 1,085 ) The amounts of revenue and net income of Newchem since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 2,369 Net income $ 184 Acquisition of Dahlquist Machine, LLC Fathom OpCo completed an acquisition of Dahlquist Machine, LLC (“Dahlquist”) on December 16, 2020 in which it acquired 100 percent of the membership interest of Dahlquist. In conjunction with the equity purchase, Fathom OpCo acquired the real estate in which Dahlquist Machine, LLC performs their operations. Dahlquist is a precision machining company with state-of-the-art computer numerical control ("CNC") mills and lathes, specializing in high-speed precision machining of light metals, aluminum, and plastics. The acquisition was consistent with Fathom OpCo's mission to acquire high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 16,098 Equity instruments 368 Contingent consideration 1,166 Fair value of total consideration transferred $ 17,632 The consideration excludes $ 804 of buyer transaction expenses that are included in other expenses within the 2020 Predecessor Period consolidated statements of comprehensive loss. In addition, Fathom Opco paid a transaction fee of $ 252 to an affiliate of the majority member of Fathom OpCo as part of the transaction. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Dahlquist: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 357 Accounts receivable, net 1,215 Inventory 1,597 Indemnification asset - PPP loan 518 Prepaid expenses 8 Fixed assets, net 3,753 Intangible assets 8,300 Total assets acquired 15,748 Accounts payable 68 Paycheck Protection Program (PPP) loan 518 Accrued expenses 475 Total liabilities assumed 1,061 Total identifiable net assets 14,687 Goodwill $ 2,945 The earnout is based upon the Dahlquist's reported earnings before interest, taxes, depreciation, and amortization for the trailing twelve-month period ending June 30, 2021. All contingent consideration balances related to the Dahlquist acquisition ($ 2,600 ) have been paid as of December 31, 2021 (Successor). Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 500 5 Customer relationships 7,800 14 Total intangible assets $ 8,300 The amounts of revenue and net (loss) of Dahlquist since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was a follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 310 Net (loss) $ ( 940 ) Acquisition of Majestic Metals, LLC Fathom OpCo completed an acquisition of Majestic Metals, LLC (“Majestic”) on December 17, 2020 in which it acquired 100 percent of the membership interest of Majestic. Majestic is a precision sheet metal fabricator and has evolved into one of the most progressive precision sheet metal products manufacturers in the nation. The acquisition is consistent with the Fathom OpCo's mission to expand its high-quality manufacturing and industrial technology capabilities in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 33,557 Equity instruments 1,471 Fair value of total consideration transferred $ 35,028 The consideration excludes $ 1,145 of buyer transaction expenses that are included in other expenses within the 2020 Predecessor Period consolidated statement of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 361 to an affiliate of the majority member of Fathom OpCo. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ ( 1 ) Accounts receivable, net 2,646 Inventory 1,184 Other current assets 30 Prepaid expenses 201 Fixed assets, net 4,229 Intangible assets 20,100 Total assets acquired 28,389 Accounts payable 244 Accrued expenses 231 Other current liabilities 644 Total liabilities assumed 1,119 Total identifiable net assets 27,270 Goodwill $ 7,758 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 1,500 5 Customer relationships 18,600 16 Total intangible assets $ 20,100 The amounts of revenue and net (loss) of Majestic since the acquisition date included in the 2020 Predecessor Period statement of comprehensive loss for the reporting periods are as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 911 Net (loss) $ ( 1,129 ) Acquisition of Summit Tooling, Inc., and Summit Plastics, LLC: Fathom OpCo completed an acquisition of Summit Tooling Inc. ("Summit Tooling") and Summit Plastics LLC (“Summit Plastics”, together with Summit Tooling, “Summit”) on February 1, 2021 in which it acquired 100 percent of the equity interests of Summit. In conjunction with the equity purchase, Fathom OpCo acquired the real estate in which Summit performs their operations. Summit Tooling designs and manufactures plastic injection molds and Summit Plastics provides molding of precision plastic components for a variety of industries. The primary reason for the acquisition was to expand Fathom OpCo's capabilities in manufacturing and expand its customer base of high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 10,875 Fair value of total consideration transferred $ 10,875 The consideration excluded $ 892 of buyer transaction expenses that are included in other expenses within the 2021 Predecessor Period consolidated statement of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 225 to an affiliate of the majority member of Fathom OpCo. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired business into Fathom OpCo's existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Summit: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 40 Accounts receivable, net 627 Inventory 339 Fixed assets, net 4,371 Intangible assets 5,000 Total assets acquired 10,377 Accounts payable 40 Deferred revenue 776 Other current liabilities 1,418 Total liabilities assumed 2,234 Total identifiable net assets 8,143 Goodwill $ 2,732 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 400 5 Customer relationships 4,600 11 Total intangible assets $ 5,000 The amounts of revenue and net loss of Summit since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Predecessor Period are as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 6,748 Net (loss) $ ( 370 ) Acquisition of Precision Process Corp.: Fathom OpCo completed an acquisition of Precision Process Corp. ("PPC") on April 30, 2021 in which it acquired 100 percent of the membership interest of PPC. In conjunction with the equity purchase, Fathom Opco acquired the real estate in which PPC performs their operations. PPC is a manufacturing company that offers integrated engineering-to-production services, specializing in making prototype, small-run and mass production of parts and components for medical, high-tech, automotive and metal stamping industries. The primary reason for the acquisition was to expand Fathom OpCo's capabilities into metal stamping with high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 25,721 Fair value of total consideration transferred $ 25,721 The consideration excludes $ 984 of buyer transaction expenses that are included in other expenses within the accompanying consolidated statements of comprehensive loss . Fathom OpCo paid a transaction fee of $ 264 to an affiliate of the majority member of Fathom OpCo. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired business into Fathom OpCo's existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of PPC: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 162 Accounts receivable, net 899 Inventory 480 Fixed assets, net 2,413 Intangible assets 14,200 Total assets acquired 18,154 Accounts payable 148 Accrued expenses 79 Total liabilities assumed 227 Total identifiable net assets 17,927 Goodwill $ 7,794 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 1,100 5 Customer relationships 13,100 17 Total intangible assets $ 14,200 The amounts of revenue and net loss of PPC since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Successor Period is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 6,993 Net (loss) $ ( 34 ) Acquisition of Centex Machine and Welding, Inc. and Laser Manufacturing, Inc.: Fathom OpCo completed acquisitions of Centex Machine and Welding, Inc. ("Centex") and Laser Manufacturing, Inc. ("Laser") on April 30, 2021 in which it acquired 100 percent of the equity interests of Centex and Laser. Centex is a top tier medical device manufacturing supplier and Laser provides high precision manufacturing services, combining state of the art technology with expert craftsmanship to deliver superior products. The acquisition was completed in order to expand Fathom OpCo's high-quality manufacturing and industrial technology capabilities in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Centex Laser Total Cash $ 11,774 $ 6,946 $ 18,720 Fair value of total consideration transferred $ 11,774 $ 6,946 $ 18,720 The consideration excluded $ 1,226 of buyer transaction expenses that are included in other expenses within the 2021 Predecessor period consolidated statements of comprehensive loss . Fathom OpCo also paid a transaction fee of $ 190 to an affiliate of the majority member of the Fathom OpCo in connection with the transaction. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired businesses into the Company’s existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Centex and Laser: Acquisition Date Fair Value Centex Laser Recognized amounts of identifiable assets acquired and liabilities assumed Cash $ - $ 68 Accounts receivable, net 1,775 900 Inventory 524 622 Prepaid expenses 108 1 Fixed assets, net 1,787 760 Intangible assets 6,243 3,557 Other assets 1 2 Total assets acquired 10,438 5,910 Accounts payable 252 568 Paycheck Protection Program (PPP) loan 649 - Accrued expenses 271 27 Other current liabilities 23 44 Other noncurrent liabilities 1,234 703 Total liabilities assumed 2,429 1,342 Total identifiable net assets 8,009 4,568 Goodwill $ 3,765 $ 2,378 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Estimated Life (Years) Trade name $ 510 5 Customer relationships 5,733 17 Total intangible assets $ 6,243 Acquisition Date Estimated Life (Years) Trade name $ 290 5 Customer relationships 3,267 17 Total intangible assets $ 3,557 The amounts of revenue and net loss of Centex and Laser since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Predecessor Period and is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 9,642 Net (loss) $ ( 98 ) Acquisition of Sureshot Precision, LLC: Fathom OpCo completed an acquisition of Sureshot Precision, LLC (d/b/a as "Micropulse West") on April 30, 2021 in which it acquired 100 percent of the membership interest of Micropulse West. Micropulse West is a full-service specialist offering a variety of services such as wire Electrical Discharge Machine (“EDM”), ram EDM, small hole EDM, CNC and manual machining/turning, surface grinding, and inspection. The acquisition was consistent with the Fathom OpCo’s mission to acquire high-quality manufacturing and industrial technology companies in North America. The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 12,452 Contingent consideration 1,295 Fair value of total consideration transferred $ 13,747 The consideration excludes $ 869 of buyer transaction expenses that are included in other expenses within the 2021 Predecessor Period consolidated statement of comprehensive loss. In addition, Fathom OpCo paid a transaction fee of $ 130 to an affiliate of the majority member of Fathom OpCo. The goodwill recognized as part of the acquisition primarily reflects the value of the assembled workforce acquired and the value of future growth prospects and expected business synergies realized as a result of combining and integrating the acquired businesses into Fathom OpCo's existing platform. The goodwill recognized is partially deductible for tax purposes. The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Micropulse West: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 70 Accounts receivable, net 866 Inventory 333 Other current assets 10 Fixed assets, net 2,490 Intangible assets 7,000 Total assets acquired 10,769 Accounts payable 139 Accrued expenses 13 Other current liabilities 99 Total liabilities assumed 251 Total identifiable net assets 10,518 Goodwill $ 3,229 Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 600 5 Customer relationships 6,400 17 Total intangible assets $ 7,000 The amounts of revenue and net loss of Micropulse West since the acquisition date included in the 2021 Predecessor Period consolidated statement of comprehensive loss is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 4,614 Net (loss) $ ( 115 ) Other acquisitions Fathom OpCo acquired substantially all assets and property, and agreed to assume certain liabilities of GPI Prototype & Manufacturing Services, LLC on August 18, 2020 for a total consideration transferred of $ 2,441 . The primary reason for the acquisition was to expand Fathom OpCo's capabilities in 3D printing as well as expand its customer based with high-quality manufacturing and industrial technology companies in North America. In addition, Fathom OpCo completed an acquisition of Mark Two Engineering, LLC (“Mark Two”) on December 18, 2020 in which it acquired 100 percent of the membership interest of Mark Two for a total consideration transferred of $ 6,639 . Mark Two is a contract manufacturing firm that specializes in rapid prototyping, complex high-precision component machining and manufacturing in the Medical Device and Aerospace industries. The acquisition is consistent with Fathom Opco's mission to expand its high-quality manufacturing and industrial technology capabilities in North America.

Revenue

Revenue	12 Months Ended
	Dec. 31, 2021
Revenue From Contract With Customer [Abstract]
Revenue	Note 5 – Revenue The Company accounts for revenue in accordance with ASC 606 . Revenue is recognized in five steps. The Company identifies the contract with the customer, identifies the performance obligations in the contract, determines the transaction price, allocates the transaction price to the performance obligations, and recognizes revenue when (or as) each performance obligation is satisfied. Collectability is a required component of a valid contract. The Company assesses collectability based on a number of factors, including the customer’s past payment history and current creditworthiness. If collectability is not considered probable at inception, the Company will not have a valid contract. The Company provides high quality, advanced rapid prototyping, precision manufacturing and finishing services in low-to-mid volume production scenarios. The Company’s suite of on-demand digital manufacturing services includes additive manufacturing, machining, and molding technologies as well as sheet metal cutting, etching, and forming solutions for customers in the aerospace and defense, electronics, medical, automotive, consumer, and industrial industries, among others. As a result, the majority of revenue recognized in a reporting period is based on completed, invoiced contracts. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in ASC 606. The majority of the Company’s Additive Manufacturing, CNC Machining, Urethane Casting, Precision Sheet Metal, and Chemical Etching contracts have a single performance obligation. The majority of the Company’s injection molding contracts have multiple performance obligations including one obligation to produce the mold and sample part and a second obligation to produce production parts. For injection molding contracts with multiple performance obligations, revenue is allocated to each performance obligation based on its relative standalone selling price. Standalone selling price is determined based on quotes to the customer that the customer accepts. Below is a listing of the Company’s major sales product lines and their recognition patterns: Additive Manufacturing Our Additive Manufacturing product line utilizes plastic and metal 3D printing technology to provide a wide-variety of high-quality, precision rapid prototyping solutions and low volume production. Performance obligations are dictated by the contractual shipping terms agreed upon by the Company and its customers. Revenue is recognized at a point in time based on shipping terms. Injection Molding Our Injection Molding product line uses our 3D CAD machining technology for the automated design and manufacture custom tooling and small to medium part production runs. Tooling and sampling production and part production runs are recognized at a point in time based on shipping terms. The majority of the Company’s injection molding contracts have multiple performance obligations including one obligation to produce the mold and sample part and a second obligation to produce production parts. For injection molding contracts with multiple performance obligations, we allocate revenue to each performance obligation based on its relative standalone selling price. CNC Machining Our CNC Machining product line delivers high-quality precision parts by way of modern machining methods to drive more outstanding results. Performance obligations are dictated by the contractual shipping terms agreed upon by the Company and its customers. Revenue is recognized at a point in time based on shipping terms. Precision Sheet Metal Our Precision Sheet Metal product line includes efficient quick-turn custom sheet metal parts from prototype to mid-volume production runs. Performance obligations are dictated by the contractual shipping terms agreed upon by the Company and its customers. Revenue is recognized at a point in time based on shipping terms. Ancillary Product Lines Urethane Casting Our Urethane Casting product line is most commonly used during prototyping, including finished looking parts for final tests and presentations, and low volume production. Performance obligations are dictated by the contractual shipping terms agreed upon by the Company and its customers. Revenue is recognized at a point in time based on shipping terms. Chemical Etching Our Chemical Etching product line provides customers the ability to quickly make complex precision parts and decorative items – beyond hard tool capability and without the cost – fabricated in dead soft or full hard material without burrs or metal distortion. Performance obligations are dictated by the contractual shipping terms agreed upon by the Company and its customers. Revenue is recognized at a point in time based on shipping terms. The remaining other product lines include, but are not limited to, in-house assistance, and industrial design, engineering services, finishing and assembly services, and customer crating and packaging. Revenue is recognized over time for professional services based on hours incurred as periodically invoiced and at a point in time based on shipping terms for the other manufacturing-related services. Revenue by product line for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period was as follows: Period From December 23 - December 31, 2021 January 1 - December 22, 2021 (Predecessor) January 1 - December 31, 2020 (Predecessor) Revenue: Additive Manufacturing $ 567 $ 17,270 $ 19,032 Injection Molding 919 27,968 17,093 CNC Machining 1,372 41,775 9,173 Precision Sheet Metal 1,700 51,751 9,811 Ancillary Product Lines 282 8,592 6,180 Total revenue $ 4,840 $ 147,356 $ 61,289 The Company generally expenses sales commissions when incurred because the amortization period would have been one year or less. These costs are recorded within selling, general, and administrative expenses. The Company’s deferred revenue balance as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor) was $ 1,147 and $ 1,210 , respectively. Deferred revenue is the result of billings in excess of revenue being recognized and is recorded in other current liabilities on the Company’s balance sheet. The Deferred revenue balances as of December 31, 2020 was recognized fully in the 2021 Predecessor Period due to the short-term nature of the customer contracts.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2021
Inventory Disclosure [Abstract]
Inventory	Note 6 - Inventory Inventory consists primarily of finished goods, raw materials and work in process, which are recorded at the lower of cost or net realizable value, which approximates first-in, first-out (“FIFO”) cost. The Company periodically reviews its inventory for slow-moving, damaged and discontinued items and provides allowances to reduce such items identified to their net recoverable amounts. The Company’s inventory consisted of the following at December 31, 2021 (Successor) and December 31, 2020 (Predecessor): December 31, December 31, Finished goods $ 3,506 $ 1,819 Raw materials 4,967 2,277 Work in process 5,368 2,359 Tooling 605 338 14,446 6,793 Allowance for obsolescence ( 1,281 ) ( 468 ) Total $ 13,165 $ 6,325

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Property and Equipment	Note 7 - Property and Equipment Property and equipment consisted of the following as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor): Period Ended December 31, 2021 December 31, 2020 Estimated Useful Life Machinery and equipment $ 33,182 $ 25,214 5 Furniture and fixtures 180 812 2 Computer hardware 499 - 2 Computer software 305 - 2 Property and leasehold improvements 7,180 2,838 3 - 23 Construction in progress 2,859 576 n/a Auto / transportation equipment 454 - 3 Total 44,659 29,440 Accumulated depreciation and amortization ( 132 ) ( 3,054 ) Total $ 44,527 $ 26,386 Depreciation expense included in operating expenses for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period was $ 60 , $ 700 , and $ 445 , re spectively. Depreciation and amortization expense included in cost of revenues for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period was $ 72 , $ 4,873 , and $ 2,567 , respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Note 8 – Goodwill and Intangible Assets The changes in the carrying amount of goodwill for the periods ended December 31, 2021 (Successor) and December 31, 2020 (Predecessor) were as follows: Jan. 1, 2020 (Predecessor) Goodwill acquired during 2020 (Predecessor) Dec. 31, 2020 (Predecessor) Goodwill acquired during 2021 (Predecessor) Dec. 22, 2021 (Predecessor) Goodwill acquired during 2021 (Successor) Dec. 31, 2021 (Successor) Goodwill $ 33,007 $ 30,208 $ 63,215 $ 19,898 $ 83,113 $ 1,189,464 $ 1,189,464 Intangible assets other than goodwill for the periods ended December 31, 2021 (Successor) and December 31, 2020 (Predecessor) were as follows: Period Ended December 31, 2021 (Successor) Gross Accumulated Amortization Net Useful Life (in years) Trade name $ 70,000 $ 98 $ 69,902 15 Customer relationships 180,000 252 179,748 19 Developed software 4,300 6 4,294 5 Developed technology 15,700 22 15,678 5 Total intangible assets $ 270,000 $ 378 $ 269,622 Period Ended December 31, 2020 (Predecessor) Gross Accumulated Amortization Net Useful Life (in years) Trade name $ 12,200 $ 919 $ 11,281 5 - 15 Customer relationships 67,600 4,448 63,152 5 - 17 Developed software 6,400 720 5,680 5 Developed technology 4,500 1,147 3,353 5 Total intangible assets $ 90,700 $ 7,234 $ 83,466 Aggregate amortization expense related to intangible assets, excluding goodwill which is not amortized, was $ 378 , $ 10,535 , and $ 4,227 for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, respectively. There are no intangible assets, other than goodwill, with indefinite useful lives. Estimated amortization expense for each of the next five years: Year ended Total 2022 $ 17,280 2023 17,280 2024 17,280 2025 17,280 2026 17,280 Thereafter 183,222 Total $ 269,622

Warrant Liability

Warrant Liability	12 Months Ended
	Dec. 31, 2021
Warrants And Rights Note Disclosure [Abstract]
Warrant Liability	Note 9 – Warrant Liability The Company's total Warrant liability as of the 2021 Successor Period is equal to the fair value of the Public Warrants plus the fair value of the Private Placement Warrants. As of the 2021 Successor Period, there were 8,625,000 Public Warrants outstanding. The Public Warrants became exercisable after February 4, 2022, or one year after the IPO of the Company (i.e., Altimar II's IPO). The Public Warrants are redeemable when the price per share of Class A common stock equals or exceeds $ 18.00 . Once the Warrants become exercisable, the Company may redeem the outstanding Warrants (except as described with respect to the Private Placement Warrants): • in whole and not in part; • at a price $ 0.01 per Warrant; • upon a minimum of 30 days ’ prior written notice of redemption to each holder of the Warrant; and • if, and only if, the closing price of the Class A ordinary shares equals or exceeds $ 18.00 per share (as adjusted) for any 20 trading days within a 30 -trading day period ending three trading days before the Company sends the notice of redemption to the holders of the Warrants. If the Company calls the Public Warrants for redemption, as described above, the Company’s management will have the option to require any holder that wishes to exercise the Public Warrants to do so on a “cashless basis,” as described in the Warrant agreement. The exercise price and number of shares of Class A common stocks issuable upon exercise of the Public Warrants may be adjusted in certain circumstances including in the event of a share dividend, extraordinary dividend or recapitalization, reorganization, merger or consolidation. However, except as described below, the Public Warrants will not be adjusted for issuances of the Class A common stock at a price below its exercise price. Additionally, in no event will the Company be required to net cash settle the Public Warrants. As of the 2021 Successor Period, there were also 9,900,000 Private Placement Warrants outstanding. The Private Placement Warrants are identical to the Public Warrants underlying the units sold in the initial public offering, except that the Private Placement Warrants and the shares of Class A common stock issuable upon the exercise of the Private Placement Warrants were not be transferable, assignable or salable until 30 days after the completion of the Business Combination, or January 22, 2022. Additionally, the Private Placement Warrants are exercisable on a cashless basis and non-redeemable, except as described so long as they are held by the initial purchasers or their permitted transferees. If the Private Placement Warrants are held by someone other than the initial purchasers or their permitted transferees, the Private placement Warrants will be redeemable by the Company and exercisable by such holders on the same basis as the Public Warrants. The below table summarizes the number of outstanding Warrants and the fair value as of the 2021 Successor Period. See Note 19 for further information. Fair Value # of Warrants December 31, 2021 (Successor) Public Warrants $ 7,600 8,625,000 Private Placement Warrants $ 26,300 9,900,000

Debt

Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt	Note 10 – Debt 2018 and 2019 Credit Facilities During 2018, Fathom OpCo entered a revolving credit agreement, a term loan and a delayed draw term loan (“DDTL”) credit agreement, which collectively make up the “2018 Credit Facilities”, to support its operations, cash requirements and acquisition growth strategy. During 2019, Fathom OpCo entered into the second and third amendments to the 2018 Credit Facilities. Under the credit agreement, Fathom OpCo was subject to various financial covenants, including quarterly fixed-charge coverage ratio, total leverage ratio, and minimum earnings before interest, taxes, depreciation, and amortization (“EBITDA”). The credit facility also included a capital expenditure limit of $ 3,100 for the period ended December 31, 2020 (Predecessor). As of December 31, 2020 (Predecessor), Fathom OpCo was in compliance with all covenant requirements. The 2018 DDTL had unused capacity of $ 510 as of December 31, 2020 (Predecessor) and was fully repaid as of December 31, 2021 (Successor). 2020 Credit Facilities On July 27, 2020, Fathom OpCo entered into a $ 34,500 secured, unsubordinated credit facility with a financial institution, consisting of a $ 19,500 term loan and a $ 15,000 delayed draw term loan, with a maturity of July 27, 2026 . At closing, $ 19,500 was funded and along with cash on Fathom OpCo’s balance sheet, used to finance the acquisition of Incodema and Newchem. The term loan credit facility resulted in issuance costs of $ 520 , which were capitalized. The loan was secured by pledged equity interests and the assets of Fathom OpCo, including, but not limited to, cash and deposits, inventory, property, plant, and equipment, and intangible assets. Under the agreements, Fathom OpCo was subject to various financial covenants, including a fixed charge coverage ratio and total net leverage ratio, and required to make quarterly principal installments commencing on September 30, 2020 and March 31, 2021 through the end of the term in the amounts of $ 50 and $ 100 for the term loan and delayed draw term loan, respectively. Borrowing under the term loan facility is in U.S. dollars and bears interest at a variable interest rate based on LIBOR plus a net leverage-based margin, which was 7.738 % per annum as of December 31, 2020 (Predecessor) . On December 16, 2020, Fathom OpCo entered into the first amendment to the 2020 Credit Facility. Pursuant to the amendment, the availability on the delayed draw term loan was increased to $ 40,500 . Fathom OpCo was charged a commitment fee of 0.5 % for the initial six-month period and 1.0 % following the six-month period on the unused portion of the delayed draw term loan. The amendment resulted in issuance costs of $ 692 of which $ 660 were capitalized and $ 32 were expensed. Borrowings on the delayed draw term loan amount were not drawn until acquisitions of Dahlquist, Mark Two, and Majestic beginning mid-December, 2020. The 2020 Delayed Draw Term Loan ("DDTL") was fully drawn as of December 31, 2020 (Predecessor) and was repaid as of December 31, 2021 (Successor). Paycheck Protection Program Loan During the period ended December 31, 2020 (Predecessor) , the Company received a Paycheck Protection Program (“PPP”) loan in the amount of $ 1,624 through the Small Business Administration (“SBA”) under the Coronavirus Aid, Relief, and Economic Security (“CARES”) Act. In April 2021, the Company’s PPP loan was forgiven in full by the SBA and the Company recorded a gain of $ 1,624 which was recorded to other income on the Company’s Consolidated Statement of Comprehensive Loss for the 2021 Predecessor Period . 2021 Term Loan On April 30, 2021, Fathom OpCo completed a financing transaction whereby it issued a $ 172,000 term loan due April 2022 (the “2021 Term Loan”) in order to finance the acquisitions of Centex, Laser, Micropulse West, and PPC, as well as to refinance the Company’s existing debt. In conjunction with the Business Combination, the Company repaid $ 20,000 of the 2021 Term Loan and the 2021 Term Loan was subsequently refinanced shortly after the closing of the Business Combination. The deferred financing costs are not recorded on the consolidated balance sheet for the 2021 Successor Period since these costs were determined to have a fair value of zero on the opening balance sheet of the Successor Company on December 23, 2021. New Credit Agreement On December 23, 2021, Fathom OpCo entered into a financing transaction, which included a $ 50,000 revolving credit facility and $ 125,000 term loan (collectively, the "New Credit Agreement"). The Company's borrowings under the revolving credit agreement were $ 27,000 at December 31, 2021. The loans made under the New Credit Agreement will mature in December 2026 . The total $ 152,000 proceeds from the New Credit Agreement were used to repay the 2021 Term Loan. The Company recorded deferred financing costs of $ 1,828 in conjunction with the New Credit Agreement and the balance is presented net within Long-term debt, net on the Company's consolidated balance sheet. The Company amortizes the deferred financing costs using the effective interest method. The revolving credit facility under the New Credit Agreement is available for working capital and other general corporate purposes and includes a letter of credit sub-facility of up to $ 5,000 . The New Credit Agreement also includes an uncommitted incremental facility, which, subject to certain conditions, provides for additional term loan facilities, an increase in commitments under the New Credit Agreement and/or an increase in commitments under the revolving credit facility, in an aggregate amount of up to $ 100,000 . T he Company is subject to various financial covenants, including quarterly net leverage and interest coverage covenants. The Company is in compliance with all debt covenants related to the New Credit Agreement as of December 31, 2021. The Company’s debt as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor) is as follows: As of December 31, 2021 As of December 31, 2020 Debt Description Interest Rate Amount Interest Rate Amount 2018 Term Loan, as amended $ - 7.75 % $ 29,700 2018 DDTL - 7.75 % 2,990 2020 Term Loan - 3-month LIBOR + 7.50 % 19,401 2020 DDTL - 3-month LIBOR + 7.50 % 40,500 New Credit Agreement Revolver 3.60 % 27,000 - New Credit Agreement Term Loan 3.72 % 125,000 - Total principal long-term debt 92,591 Debt issuance costs ( 1,812 ) ( 1,867 ) PPP and other loans - 2,615 Total debt 150,188 93,339 Less: current portion of long-term debt 29,697 2,853 Long-term debt, net of current portion $ 120,491 $ 90,486 The balance of the Term Loan matures as follows: Year ended Total 2022 $ 3,096 2023 5,982 2024 8,453 2025 7,836 2026 99,633 Thereafter - Total $ 125,000 Interest on all debt is payable quarterly, with the unpaid amount due upon maturity. Interest expense associated with long-term debt for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period was $ 251 , $ 13,063 , and $ 3,635 , respectively. Included in interest expense, net on the accompanying consolidated statements of comprehensive loss is amortization of debt issuance costs o f $ 16 , $ 3,126 , and $ 205 for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period , respectively. In December 2021, Fathom OpCo entered into a financing agreement through its insurance broker to spread the payment of its annual director’s and officer’s insurance premium over a ten-month period. Total financed payments of $ 3,001 , including a $ 35 financing fee at 2.57 % annual rate, will be made between January 2022 and October 2022.

Other Income and Expense, Net

Other Income and Expense, Net	12 Months Ended
	Dec. 31, 2021
Other Income And Expenses [Abstract]
Other Income and Expense, Net	Note 11 – Other income and expense, net Other Income and expense, net is comprised of the following for the periods ended December 31, 2021 (Successor), December 22, 2021 (Predecessor), and December 31, 2020 (Predecessor): Period From December 23 - December 31, January 1 - December 22, January 1 - December 31, Acquisition expenses $ - $ 4,045 $ 1,254 Transaction expense - 12,515 - Loss on debt extinguishment - 2,031 - Loan prepayment fees - 1,463 - Change in fair value of contingent consideration - - 1,055 Change in fair value of TRA 300 - - Loss on sale of assets - 307 - Other 8 646 1,515 Other expense 308 21,007 3,824 Gain on sale of assets - - ( 214 ) Gain on PPP forgiveness - ( 1,624 ) - Change in fair value of Sponsor Earnout Shares ( 3,400 ) - - Change in fair value of contingent consideration ( 23,860 ) ( 3,550 ) - Change in fair value of Warrants ( 8,200 ) - - Other - - ( 371 ) Other income ( 35,460 ) ( 5,174 ) ( 585 ) Other (income) and expense, net $ ( 35,152 ) $ 15,833 $ 3,239

Share Based Compensation

Share Based Compensation	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Share Based Compensation	Note 12 - Share Based Compensation Successor On December 23, 2021, the Company executed the Fathom Digital Manufacturing 2021 Omnibus Incentive Plan (the "2021 Omnibus Plan") to encourage the profitability and growth of the Company through short-term and long-term incentives that are consistent with the Company's objectives. The 2021 Omnibus Plan provides that the Company may grant options, stock appreciation rights, restricted shares, restricted stock units, performance-based awards (including performance-based restricted shares and restricted stock units), other share-based awards, other cash-based awards, and any combination of the foregoing. In connection with the closing of the Business Combination on December 23, 2021, all vested time-based phantom unit awards issued under the Combined Phantom Plan outstanding immediately prior to the closing of the Business Combination were cancelled and replaced with grants of restricted Shares of Class A common stock, issued under the 2021 Omnibus Plan. These newly issued restricted shares will vest upon the Company filing an effective registration statement on Form S-8 with the SEC, subject to the continued service of the applicable recipient through such date. Also, in connection with the closing of the Business Combination, all unvested time-based phantom unit awards issued under the Combined Phantom Plan outstanding immediately prior to the closing of the Business Combination were cancelled and replaced with grants of time-based restricted stock units issued under the 2021 Omnibus Plan. These new issued time-based restricted stock units vest based on what the remaining vest period was under the original award issued under the Combined Phantom plan immediately prior to the Business Combination. Also, in connection with the closing of the Business Combination, all performance-based phantom unit awards issued under the Combined Phantom Plan outstanding immediately prior to the closing of the Business Combination were cancelled and replaced with grants of performance-based restricted stock units, issued under the 2021 Omnibus Plan. These new issued performance-based restricted stock units vest when and if the CORE-affiliated limited partnerships (the "CORE Investors") meet certain "sell-down" thresholds related to the Class A Common stock held by both CORE Investors and affiliates of the CORE Investors as a result of the Business Combination and prior to any sell-downs. The sell-down thresholds are referred to as a "Investor Cumulative Sale Percentage Threshold". The performance-based awards vest in 25 %, 25 %, and 50 % increments only when an Investor Cumulative Sale Percentage Threshold of 60 %, 80 %, and 95 % respectively, are met. No such Investor Cumulative Sale Percentage Thresholds were reached in the 2021 Successor Period. In accordance with ASC 718 "Stock Compensation", both the time-based awards and the performance-based awards that were cancelled and concurrently replaced with awards issued under the 2021 Omnibus Plan are subject to modification accounting. In accordance with ASC 718, the awards are treated as if they are new awards issued as of December 23, 2021. The following table summarizes the activity related to awards issued by the Company in the 2021 Successor Period under the 2021 Omnibus Plan. Successor Shares Weighted Average Grant Date Fair Value Non-vested at December 23, 2021 - - Granted 6,472,617 $ 8.21 Vested - - Forfeited - - Non-vested at December 31, 2021 6,472,617 $ 8.21 The fair value of the time-based and performance-based awards issued under the 2021 Omnibus Plan were valued using the closing stock price for the Company's Class A common stock on December 23, 2021 (i.e., the grant date), less a discount for lack of marketability ("DLOM") due to certain transfer restrictions applicable to the awards. The closing stock price at the end of business of December 23, 2021 was $ 10.53 and the DLOM was determined to be $ 2.84 per share, therefore, the fair value per award granted was determined to be $ 7.69 per share. The DLOM was calculated using an average of two valuation techniques; an Asian put model and a Finnerty model. The assumptions included in these models include a risk free rate ranging from 0.07 % to 0.97 %, volatility ranging from 75.4 % to 107.8 %, and a dividend yield of 0 %. The weighted average term utilized for the DLOM is 2.4 years. Due to the application of modification accounting under ASC 718, the time-based awards were determined to have a grant date fair value of $ 10.00 per award, which is the fair value of the time-based awards immediately prior to being modified. Since the fair value of the time-based awards immediately after being modified was determined to be $ 7.69 per award as discussed above, the higher fair value per award is utilized as the grant date fair value for the time-based awards granted on December 23, 2021. The performance-based awards were determined to have a grant date fair value of $ 7.69 per award in accordance with modification accounting under ASC 718 since, immediately prior to being modified, the performance condition underlying the performance-based awards was not yet considered probable. The weighted average grant date fair value of all awards granted on December 23, 2021 is $ 8.21 per award. The share based compensation recognized in the 2021 Successor Period is $ 139 . As of the December 31, 2021 (Successor), there was $ 5,800 of total unrecognized compensation cost related to the awards issued under the 2021 Omnibus Plan. The cost was expected to be recognized over a weighted average period of 2.8 years. No awards issued under the 2021 Omnibus Plan vested in the 2021 Successor Period. There were no cash payments related to the 2021 Omnibus Plan awards made during the 2021 Successor Period. The Company’s accounting policy is to record forfeitures as they occur, however there were no forfeitures of any awards in the 2021 Successor Period. Predecessor Prior to July 15, 2021, Fathom OpCo's operating subsidiaries, MCT Holdings and Incodema Holdings, maintained the MCT Group Holdings, LLC 2019 Phantom Equity Bonus Plan (the “MCT Phantom Plan”) and the Incodema Holdings LLC 2020 Phantom Equity Bonus Plan, respectively, (the “Incodema Phantom Plan”, together with the MCT Phantom Plan, the “Prior Phantom Plans”). The awards under both the Prior Phantom Plans had two vesting components: (1) time vesting and; (2) performance vesting. A quarter ( 25 %) of the awards vested ratably, in equal installments, on each of first four vesting commencement date anniversaries. The remaining three-quarters ( 75 %) of the awards vest if the MCT Holdings and Incodema Holdings investors realized a Multiple on Invested Capital (“MOIC”) of at least 2x upon the consummation of such sale of each company. The awards are representative of a portion of a phantom bonus pool that is created upon a change in control of Fathom OpCo, allowing for a phantom bonus pool of up to 10 % of the proceeds attributable to the Class A and Class B common units of Fathom OpCo upon a change of control, so long as the CORE investors realize a MOIC of at least 2x for each respective company. The awards issued under the Prior Phantom Plans were within the scope of ASC 718 and were equity-classified. In the 2020 Predecessor Period, the total share-based compensation expense related to the time-based awards issued under the Prior Phantom Plans was $ 34 . No compensation cost related to the performance-based awards issued under the Prior Phantom Plans was recognized in the 2020 Predecessor Period since the performance-based awards' performance condition was never met and thus no performance-based awards issued under the Prior Phantom Plans ever vested. On July 15, 2021, the Prior Phantom Plans and all awards outstanding thereunder were terminated and replaced by a single phantom equity plan (the “Combined Phantom Plan”) sponsored by Fathom OpCo. The new awards issued under the Combined Phantom Plan retained identical vesting provisions for both the time-based and performance-based awards as those that existed under the Prior Phantom Plans; however, the awards issued under the Combined Phantom Plan also included additional separate vesting conditions if Fathom OpCo completed a business combination with a special purpose acquisition company. Due to the change in vesting conditions, the cancellation of the Prior Phantom Plan awards and their concurrent replacement with Combined Phantom Plan awards was accounted for as a modification of share-based awards under ASC 718. Since the performance-based awards were subject to modification accounting under ASC 718, the performance-based awards were considered an improbable-to-improbable modification and thus the grant date fair value of the performance based-awards was reset as of the modification date which was July 15, 2021. The time-based awards were also considered subject to modification accounting, however the time-based awards were considered a probable-to-probable modification whereby the original grant date fair value of the award is retained for accounting purposes. For both the modified time-based and performance based awards, the fair value of the original award and the fair value of the modified award were deemed to have the same fair value as there were no changes to the inputs in the calculation of fair value of the awards. As such, there was no incremental fair value that needed to be recognized for either the time-based or performance-based awards as a result of modification accounting for such awards. For the 2021 Predecessor Period, the share-based compensation related to awards under both the Prior Phantom Plans and the Combined Phantom Plans totaled $ 2,649 . All compensation recorded in Predecessor Periods relates to time-based awards, as no performance-based awards ever vested under either the Prior Phantom Plans or the Combined Phantom Plan. The fair value of awards granted under the Prior Phantom Plans was determined based on an equity valuation of MCT Holdings and Incodema Holdings as of the date that the award was granted. As discussed previously, the Prior Phantom Plan time-based awards that were cancelled and replaced with Combined Phantom Plan awards on July 15, 2021 were considered probable-to-probable modifications and therefore the original grant date fair value was retained for purposes of determining the stock compensation expense to be recognized in the 2021 Predecessor Period. As of December 31, 2020 (Predecessor), there was $ 554 of total unrecognized compensation cost related to the Prior Phantom Plan Units. The cost was expected to be recognized over a weighted average period of 2.8 years. The total fair value of shares vested during the 2020 Predecessor Period was $34. No cash payments related to the Phantom Units were made during the 2020 Predecessor Period. Fathom OpCo's accounting policy was to record forfeitures as they occur, however there were no forfeitures of any awards in the Predecessor Periods. A summary of the activity in the plan for the 2020 Predecessor Period is as follows: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2020 4,000 $ 515.09 Granted 5,356 358.15 Vested ( 313 ) 570.20 Forfeited - - Non-vested at December 31, 2020 9,043 $ 420.02 A summary of the activity in the plans for the 2021 Predecessor Period is as follows: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2021 9,043 $ 420.02 Granted 14,346 1,529.06 Vested ( 1,115 ) 1,930.42 Forfeited ( 10,706 ) 888.81 Non-vested at December 22, 2021 11,568 $ 1,217.42

Earnings Per Share and Earnings

Earnings Per Share and Earnings Per Unit	12 Months Ended
	Dec. 31, 2021
Earnings Per Unit [Abstract]
Earnings Per Share and Earnings Per Unit	Note 13 –Earnings Per Share and Earnings per Unit Successor Basic net loss per share is computed based on the weighted average number of common shares outstanding. Diluted net loss per share is computed based on the weighted average number of common shares outstanding, increased by the number of any additional shares that would have been outstanding had any potentially dilutive common shares been issued and reduced by the number of units the Company could have repurchased from the proceeds from issuance of the potentially dilutive shares. Only the Company's Class A common stock participates in the Company’s undistributed earnings. As such, the Company’s undistributed earnings are allocated entirely to shares of Class A common stock based on the weighted Class A common stock outstanding during the 2021 Successor Period. The Company's basic earnings per share calculation is as follows: Period From December 23 - December 31, Class A Basic Earnings Per Share: Numerator Net income $ 33,470 Less: Net loss attributable to non-controlling interests ( 968 ) Net income attributable to Class A common stock $ 34,438 Denominator Weighted average shares of Class A common stock outstanding-basic 50,785,656 Basic Earnings Per Share $ 0.68 The Company's diluted earnings per share calculation is as follows: Period From December 23 - December 31, Class A Diluted Earnings Per Share: Numerator Net income attributable to holders of Class A common stock $ 33,470 Denominator Weighted average shares of Class A common stock outstanding-basic 50,785,656 Effect of Dilutive Securities Assumed exchange for shares of Class A common stock 85,054,317 Weighted average shares of Class A common stock outstanding-diluted 135,839,973 Diluted Earnings Per Share $ 0.25 Predecessor Basic net loss per unit is computed based on the weighted average number of common units outstanding. Diluted net loss per unit is computed based on the weighted average number of common units outstanding, increased by the number of any additional units that would have been outstanding had any potentially dilutive common units been issued and reduced by the number of units Fathom OpCo could have repurchased from the proceeds from issuance of the potentially dilutive units. Fathom OpCo had no dilutive instruments outstanding as of December 22, 2021 (Predecessor) and December 31, 2020 (Predecessor). As a result, basic and diluted earnings per units are the same as of December 22, 2021 (Predecessor) and December 31, 2020 (Predecessor). Fathom OpCo's Class A common units and Class B common units participate equally in Fathom OpCo's undistributed earnings. As such, Fathom OpCo’s undistributed earnings are allocated pro-rata to the Class A common units and Class B common units based on the weighted Class A common units and Class B common units outstanding as of December 22, 2021 (Predecessor) and December 31, 2020 (Predecessor) such that earnings per unit for Class A common units and Class B common units are the same in each period. Period From January 1 - December 23, January 1 - December 23, Class A Class B Basic and Diluted Earnings Per Unit: Numerator Net (loss) $ ( 11,690 ) $ ( 4,784 ) Less: annual dividends on redeemable preferred units ( 6,582 ) ( 2,694 ) Net (loss) attributable to common unitholders $ ( 18,272 ) $ ( 7,478 ) Denominator Weighted-average units used to compute basic earnings per unit 5,480,611 2,242,981 Basic and Diluted Earnings Per Unit $ ( 3.33 ) $ ( 3.33 ) Period From January 1 - December 31, January 1 - December 31, Class A Class B Basic and Diluted Earnings Per Unit: Numerator Net (loss) $ ( 5,380 ) $ ( 2,583 ) Less: annual dividends on redeemable preferred units ( 4,083 ) ( 1,961 ) Net (loss) attributable to common unitholders $ ( 9,463 ) $ ( 4,544 ) Denominator Weighted-average units used to compute basic earnings per unit 3,531,681 1,696,135 Basic and Diluted Earnings Per Unit $ ( 2.68 ) $ ( 2.68 )

Shareholders' Equity, Noncontro

Shareholders' Equity, Noncontrolling Interest, and Members' Equity	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Shareholders' Equity, Noncontrolling Interest, and Members' Equity	Note 14 – Shareholders’ Equity, Noncontrolling interest, and Members' Equity Successor The Company’s equity consists of a total of 500,000,000 authorized shares across all classes of capital stock, which the Company has the authority to issue. The 500,000,000 authorized shares consist of 10,000,000 authorized shares of preferred stock with a par value of $ 0.0001 per share, 300,000,000 authorized shares of Class A common stock with a par value of $ 0.0001 per share, 180,000,000 shares of Class B common stock with a par value of $ 0.0001 par value per share, and 10,000,000 shares of Class C common stock with a par value of $ 0.0001 per share. As of December 31, 2021, the Company had no outstanding shares of Preferred Stock, 50,785,656 outstanding shares of Class A common stock, 84,294,971 outstanding shares of Class B common stock, and no outstanding shares of Class C common stock. Shares of Class A common stock are entitled to economic rights and one vote per share . Shares of Class B common stock have no economic rights and one vote per share . The number of shares of Class B common stock is equal to the number of New Fathom Units held by the continuing Fathom Owners (as defined below). The New Fathom Units owned by the legacy pre-Business Combination owners (the "Continuing Fathom Unitholders") of Fathom OpCo are exchangeable on a one-for-one basis for shares of Class A common stock (with corresponding surrender of an equal number of shares of Class B common stock for cancellation by the Company). The Company and Fathom OpCo also have the option to redeem the class A units for cash in lieu of shares of Class A common stock. Due to the potential that the Class A units of Fathom OpCo may be redeemed for cash and the redemption is considered outside of the control of the Company, the Company has accounted for the non-controlling interest in Fathom OpCo within temporary or "mezzanine" equity on the Consolidated Balance Sheet as of December 31, 2021 (Successor). The Company's shares of Class C common stock have identical rights to shares of the Company's Class A common stock. However, there are no outstanding shares of Class C common stock as of December 31, 2021 (Successor). Further, the Company's certificate of incorporation prohibits any future issuance of shares of Class C common stock. The Company expects to amend its certificate of incorporation in 2023 to eliminate Class C common stock from its capital structure entirely. The Company's shares of preferred stock are authorized but unissued as of December 31, 2021 (Successor). The Company, acting without shareholder approval, may approve the issuance of one of more series of such preferred shares. In connection with such approval, the Company will approve a "Certificate of Designation" that will set forth the terms of the series of preferred stock, including terms such as dividends and redemption rights. Due to the New Fathom Units held by parties other than the Company, upon the closing of the Business Combination, the Company recorded a non-controlling interest at fair value, which was $ 842,850 . The non-controlling interest is reflective of the fact that the Company owns a 37.6 % economic interest in Fathom OpCo whereas the Continuing Fathom Unitholders hold the remaining 62.4 % economic interest in Fathom OpCo. The table below demonstrates the calculation of the comprehensive loss attributable to the non-controlling interest holders for the 2021 Successor Period. Period From December 23 - December 31, Fathom OpCo comprehensive loss $ ( 1,551.00 ) Noncontrolling interest percentage 62.4 % Comprehensive loss attributable to noncontrolling interest $ ( 968.00 ) Predecessor Fathom OpCo's equity in the 2020 Predecessor Period and 2021 Predecessor Period consists of Class A common units and Class B common units. See Note 4 for member units issued as part of business combination transactions in the periods ended 2021 Predecessor Period and 2020 Predecessor Period . Unit holders of Class A common units and Class B common units share equally in the undistributed income of the Company after consideration of the cumulative unpaid dividends related to the Class A Preferred Units. Allocations and distributions to incentive units are subject to certain participation thresholds set by the managers of Company. Unit holders of Class A common units are entitled to one vote per Class A common unit held and unit holders of Class B common units are not entitled to vote . The following table represents a summary of the Company’s Members' Equity as of December 31, 2020 (Predecessor): December 31 Class A common units 5,480,611 Class B common units 2,242,981

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2021
Leases, Operating [Abstract]
Operating Leases	Note 15 - Operating Leases The Company accounts for leases in accordance with ASC 840. The Company enters into leases in the normal course of business primarily for office space, manufacturing facilities and certain company vehicles and equipment and finance leases for certain company equipment. T he Company is obligated under non-cancellable lease agreements for certain facilities, which frequently include renewal options and escalation clauses. For leases that contain predetermined fixed escalations, we recognize the related rent expense on a straight-line basis and record the difference between the recognized rent expense and amounts payable under the lease as deferred rent. The Company includes lease extension and termination options in the lease term if, after considering relevant economic factors, it is reasonably certain the Company will exercise the option. The Company’s leases have remaining lease terms ranging from 2 to 7 years . The Company determines if an arrangement is a lease at inception. Operating leases are off balance sheet arrangements with rent expense included in Cost of revenue and Selling, general and administrative in the consolidated statements of comprehensive income (loss). Future noncancelable operating lease commitments are as follows: Year ended Total 2022 $ 3,212 2023 3,027 2024 1,959 2025 1,253 2026 443 Thereafter 328 Total future lease payments $ 10,222 Rental expense was approximately $ 53 , $ 2,226 , and $ 1,536 for the 202 1 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period , respectively.

Fathom OpCo Class A Contingentl

Fathom OpCo Class A Contingently Redeemable Preferred Units	12 Months Ended
	Dec. 31, 2021
Temporary Equity Disclosure [Abstract]
Fathom OpCo Class A Contingently Redeemable Preferred Units	Note 16 — Fathom OpCo Class A Contingently Redeemable Preferred Units Fathom OpCo had the following contingently redeemable preferred units issued and outstanding at December 31, 2020 (Predecessor): Shares Authorized Shares Issued and Outstanding Original Issue Price Carrying Value Accumulated Unpaid Dividends Amount Contingently Redeemable Class A Preferred Units 1,167,418 1,167,418 $ 46.35 $ 54,105 $ 9,253 $ 63,358 The rights and preferences of holders of the redeemable convertible preferred stock are as follows: Dividends Fathom OpCo's Class A Contingently Redeemable Preferred Units (“Class A Preferred Units”) were issued at $ 100 par per unit and accumulate a preferred return at 8.0 percent, compounded on the first business day of each calendar quarter in respect of the prior calendar quarter. Fathom OpCo does not record any changes in carrying value of the Class A Preferred Units due to cumulative unpaid dividends. Dividends are accrued at the time they are declared by the Company’s Board of Managers. No dividends were declared or paid on the Class A Preferred Units in the 2020 Predecessor Period and 2021 Predecessor Period. Voting Rights Class A Contingently Redeemable Preferred unitholders are not entitled to voting rights. Redemption The Company shall make a distribution to each of the Class A preferred unitholders in an amount equal to the aggregate Class A preferred unpaid yield and Class A preferred unreturned capital, effective upon the occurrence of any of the following events (referred to as a “redemption event”): the sale, lease, license, transfer, conveyance or other disposition of a majority of the assets of the subsidiaries of the Company; the merger, consolidation, recapitalization, reorganization or sale of securities; any merger, consolidation, joint venture or other business combination pursuant to which the Company is combined with that of a special purpose acquisition company or other blank-check company which has a class of equity securities publicly listed on a national securities exchange; or a public offering with respect to Incodema Holdings or any of its subsidiaries, the reorganization of Incodema Holdings or any of its subsidiaries from a limited liability company to a corporation (whether or not in connection with a public offering) or an election by Incodema Holdings to be treated as a corporation for U.S. federal income tax purposes. As a result, the Class A Preferred Units were recorded separately from members’ equity because they are redeemable upon the occurrence of redemption events that are considered not solely within the Company’s control. The Company expensed issuance costs related to the Class A Preferred Stock as incurred for the 2020 Predecessor Period. The amounts expensed were immaterial to the Company’s financial statements.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Note 17 - Related Party Transactions Affiliate Purchases For the 2021 Successor Period, 2021 Predecessor Period and 2020 Predecessor Period, certain employees of the Company had a non-controlling ownership interest in an affiliated entity, Fathom Precision International Ltd., which supplies services to the Company. Purchases from such affiliate totale d $ 700 , $ 9,165 , and $ 6,438 for the 2021 Successor Period, the 2021 Predecessor Period, and the 2020 Predecessor Period, respectively. Management Fees MCT Holdings and Incodema Holdings entered into a management services agreement with an entity related through common ownership to the majority member in August 2018 and July 2020, respectively. For the periods ended 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, the Company incurred expenses related to such management fees of approximately $ 0 , $ 1,723 , and $ 722 , respectively. This agreement terminated in connection with the closing of the Business Connection.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Segment Reporting	Note 18 — Segment Reporting Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing operating performance. In consideration of ASC 280, we are not organized around specific services or geographic regions. Our chief operating decision maker uses consolidated financial information to evaluate our performance, which is the same basis upon which the results and performance of the Company are communicated to the Company's Board. The chief operating decision maker bases all significant decisions regarding the allocation of our resources on a consolidated basis. Based on the information described above and in accordance with the applicable literature, management has concluded that we are organized and operate as one operating and reportable segment.

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurement	Note 19 – Fair Value Measurement The fair value of the Company’s financial assets and liabilities reflects the Company’s management’s estimate of amounts that the Company would have received in connection with the sale of the assets or paid in connection with the transfer of the liabilities in an orderly transaction between market participants at the measurement date. In connection with measuring the fair value of its assets and liabilities, the Company seeks to maximize the use of observable inputs (market data obtained from independent sources) and to minimize the use of unobservable inputs (internal assumptions about how market participants would price assets and liabilities). The following fair value hierarchy is used to classify assets and liabilities based on the observable inputs and unobservable inputs used in order to value the assets and liabilities: • Level 1 — Quoted prices in active markets for identical assets or liabilities. An active market for an asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. • Level 2 — Observable inputs other than Level 1 inputs. Examples of Level 2 inputs include quoted prices in active markets for similar assets or liabilities and quoted prices for identical assets or liabilities in markets that are not active. • Level 3 — Unobservable inputs based on our assessment of the assumptions that market participants would use in pricing the asset or liability. The following table presents information about the Company’s liabilities that are measured at fair value on a recurring basis as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor) and indicates the fair value hierarchy of the valuation inputs the Company utilized to determine such fair value: Period Ended Description Level December 31, 2021 December 31, 2020 Liabilities: Tax receivable agreement 3 $ 4,600 $ - Legacy Fathom OpCo acquisitions contingent consideration 3 3,598 11,439 Sponsor earnout shares liability 3 9,380 - Fathom earnout shares liability 3 64,300 - Warrant liability – Public Warrants 1 7,600 - Warrant liability – Private Placement Warrants 3 26,300 - $ 115,778 $ 11,439 Tax Receivable Agreement The fair value of the TRA is based on multiple inputs and assumptions input into a Monte Carlo simulation model. The significant inputs into this model are the following: a corporate tax rate of 26.9 %, an annual TRA payment date of February 16, existing non-controlling interest percentage of 37.6 %, initial amortization deductions of $ 52,400 , $ 126,000 of taxable income forecast by 2030, a sell-down schedule which reflects the expected sale of New Fathom Units by legacy Fathom OpCo shareholders, a Class A common stock price as of December 31, 2021 (Successor) of $ 7.92 , volatility of 84.6 %, correlation between taxable income and the Class A common stock price of 25 %, and a cost of debt range from 2.4 % to 8.5 % Legacy Fathom OpCo Acquisitions Contingent Consideration The fair values for contingent consideration payable are determined by using a discounted cash flow approach with unobservable inputs and is classified as a Level 3 liability in the fair value hierarchy. The Company’s assessment of the significance of particular inputs to these fair value measurements requires judgment and considers factors specific to each entity to which the contingent consideration relates to, for example EBITDA targets for a given period. Earnout Shares liability The Earnout Shares are accounted for as liabilities in the Company's consolidated balance sheet. The fair values for the Earnout Shares are estimated using a Monte Carlo simulation assuming Geometric Brownian Motion in a risk-neutral framework. The Monte Carlo simulation considers daily simulated stock prices as a proxy for the Company's daily volume-weighted average price ("VWAP"). The key inputs into the valuation of the Earnout Shares are an expected term of five years , a risk-free rate of 1.25 %, operating asset volatility of 87.6 %, and equity volatility of 91.7 %. The operating asset volatility and the equity volatility assumptions are based on a blended average of operating and equity volatility, respectively, of publicly traded companies within the Company's peer group. Warrants The Public and Private Placement Warrants are accounted for as liabilities in accordance with ASC 815-40 and are presented within Warrant liability in the accompanying consolidated balance sheet as of December 31, 2021 (Predecessor). The Warrant liabilities are measured at fair value at inception and on a recurring basis, with changes in fair value presented within change in fair value of Warrant liabilities in the statement of operations. The Public Warrants are valued using a Monte Carlo simulation model; however, the inputs are calibrated such that the fair value of an individual Public Warrant is equal to the quoted and publicly traded prices for the Public Warrants. Since the fair value is based off quoted prices in an active market for identical instruments, the Public Warrants are considered to be a Level 1 fair value measurement. Since the Public Warrants are publicly traded, the price of the underlying Class A common stock, the remaining time until expiration, and the price of the Public Warrants are observable. The Monte Carlo simulation model is calibrated by adjusting the selected volatility until the value of the Public Warrants implied by the model is equal to the publicly traded Class A warrant price (Ticker: FATH.WS). The key inputs to the valuation of the Public Warrants include an expected term of 5.0 years, a strike price of $ 11.50 , an assumption that the warrants can be early redeemed when the price of the Company's Class A common stock exceeds $ 18.00 for any 20 trading days within a 30 -day trading period, and the warrants are assumed to remain outstanding until maturity unless they are redeemed early. The Private Placement warrants are valued using a Monte Carlo simulation model, which is considered to be a Level 3 fair value measurement. The volatility for the Private Placement warrants, a key input into the valuation, was estimated to be 25 % based on a calibration to the publicly traded per share price of the Company's Class A common stock as of December 31, 2021 (Successor). Other key inputs into the valuation include a term of 5.0 years, a strike price of $ 11.50 per share, and an assumption that the Private Placement warrants will remain outstanding until maturity since, unlike the Public Warrants, the Private Placement warrants are not redeemable. In instances whereby inputs used to measure fair value fall into different levels in the above fair value hierarchy, fair value measurements in their entirety are categorized based on the lowest level input that is significant to the valuation. The Company’s assessment of the significance of particular inputs to these fair value measurements requires judgment and considers factors specific to each asset or liability. Period Ended December 31, 2021 (Successor) December 31, 2020 (Predecessor) Balance of recurring Level 3 liabilities at beginning of period $ 141,438 $ - Total gains or losses for the period: Included in earnings (income) loss ( 33,260 ) 1,055 Issuances - 11,737 Payments - ( 1,353 ) Transfers into level 3 - - Transfers out of level 3 - - Balance of recurring level 3 liabilities at end of period $ 108,178 $ 11,439

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 20 – Commitments and Contingencies Corporate Lawsuits: The Company is subject to various claims and lawsuits that arise in the ordinary course of business. It is the opinion of management that the disposition or ultimate resolution of such claims and lawsuits will not have a material effect on the consolidated balance sheet of the Company. In July 2021, the Company entered into a settlement agreement in a hybrid collective/class action complaint filed by one of its former employees for alleged violations of the Fair Labor Standards Act and Wisconsin wage and hour law. The settlement amount did not have a material effect on the consolidated balance sheet of the Company.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 21 – Income Taxes Following the Business Combination, the Company is a U.S. C-corporation which wholly owns two entities taxed as corporations. Each of the Company and its corporate subsidiaries have an ownership interest in Fathom OpCo and are subject to U.S. federal and state income taxes with respect to their allocable share of taxable income of Fathom OpCo as well as any standalone taxable income or loss generated at the corporation level. All business operations are held within Fathom OpCo and its subsidiaries. Fathom OpCo and its subsidiaries are treated as flow-through entities for federal and substantially all state income tax purposes and therefore are not subject to entity level taxes in most jurisdictions. During the 2021 Predecessor Period, certain subsidiaries of Fathom OpCo which were previously held as corporations for U.S. federal tax purposes, were reorganized into flow-through entities in non-taxable transactions. As a result, deferred tax liabilities pertaining to the corporate subsidiaries were reversed as income tax benefits during the 2021 Predecessor Period and for the 2021 Successor Period, Fathom OpCo and its subsidiaries are flow-through entities for U.S. federal income tax purposes. As of December 31, 2021, tax years 2018 through 2021 remain open and subject to examination by the Internal Revenue Service and the majority of the states where Fathom OpCo has activities. Upon audit, tax authorities may challenge tax positions of the Company or Fathom OpCo. A tax position successfully challenged by a taxing authority could result in an adjustment to the Company’s provision for income taxes in the period in which a final determination is made. As of 2021 Successor Period, 2021 Predecessor Period and the 2020 Predecessor Period, the Company did no t recognize income tax expense or benefits associated with uncertain tax positions. Significant components of the Company’s tax expense (benefit) for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, are as follows: Period From December 23 - December 31, 2021 (Successor) January 1 - December 22, 2021 (Predecessor) January 1 - December 31, 2020 (Predecessor) Current expense State $ - $ 52 $ - Federal - - - Subtotal - 52 - Deferred tax benefit State ( 1 ) ( 297 ) - Federal ( 2 ) ( 2,963 ) - Subtotal ( 3 ) ( 3,260 ) - Total $ ( 3 ) $ ( 3,208 ) $ - A reconciliation of the expected statutory federal tax and the total income tax expense (benefit) for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, are as follows: Period From December 23 - December 31, 2021 (Successor) January 1 - December 22, 2021 (Predecessor) January 1 - December 31, 2020 (Predecessor) Federal statutory rate ( 21 %) $ 7,028 $ ( 4,133 ) $ ( 1,672 ) State income taxes, net of federal benefit ( 38 ) ( 245 ) - Pre-closing income held in flow-through entities - 4,133 1,672 Change in tax status of corporate subsidiaries - ( 2,963 ) - Non-controlling interest in Fathom Holdco, LLC 222 - - Remeasurement of Fathom and Sponsor earnout shares ( 5,724 ) Remeasurement of TRA and warrant liability ( 1,662 ) - - Valuation allowance 171 - - Total $ ( 3 ) $ ( 3,208 ) $ - The tax effect of temporary differences that give rise to deferred tax assets and liabilities for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period are as follows: Period Ended December 31, 2021 (Successor) December 31, 2020 (Predecessor) Deferred tax assets Net operating losses $ 1,494 $ - Transaction costs 861 Interest expense carryforwards 762 Valuation allowance ( 3,117 ) - Total deferred tax assets - - Deferred tax liabilities Investment in Fathom Holdco, LLC ( 17,570 ) - Total deferred tax liabilities ( 17,570 ) - Total net deferred tax liabilities $ ( 17,570 ) $ - Net Operating Losses As of December 31, 2021, the Company has federal and state net operating loss ("NOLs") carryforwards of $ 5.6 million. The U.S. federal NOLs are not subject to expiration. Utilization of the federal and state net operating losses may be subject to annual limitations due to the “change in ownership” provisions of the Internal Revenue Code and equivalent state tax provisions. The annual limitations are not expected to restrict the use of any portion of the net operating losses prior to expiration. Nonetheless, the Company believes that it is more likely than not that the benefit from federal and state NOL carryforwards will not be realized. Valuation Allowance The Company recorded a valuation allowance against the use of its deferred tax assets as the date of the Business Combination and as of December 31, 2021. The change in the valuation allowance during the 2021 Successor Period was the result of an increase in deferred tax assets which the Company has fully valued against as of the end of the 2021 Successor Period. The Company determined that there is uncertainty as to its ability to generate taxable income required to use the Company’s NOLs based on its history of taxable losses. TRA, Warrants, Fathom Earnout Shares, and Sponsor Earnout Shares The Company entered into a TRA with members of Fathom OpCo which calls for certain payments to be made to members of Fathom OpCo on account of (i) tax savings generated at the Company related to tax attributes of the Company and Fathom OpCo acquired by the Company in the Business Combination and (ii) future exchanges of Fathom OpCo units for cash or Class A common stock of the Company (See note 2 for further information). Payments required under the TRA for units acquired in the Business Combination are not anticipated to give rise to substantial amounts of future deductible tax differences. As a result, changes in the fair value of the TRA liability established in connection with the transactions contemplated by the Business Combination give rise to permanent differences between financial and taxable income. The Company's Fathom Earnout Shares liability and Sponsor Earnout Shares liability to be paid in the form of equity does not give rise to future deductible tax basis for U.S. federal income tax purposes, and accordingly, changes in the fair value of the Fathom Earnout Shares liability and the Sponsor Earnout Shares liability give rise to permanent differences between financial and taxable income. The Company’s Warrants are treated as equity instruments for U.S. federal income tax purposes, and accordingly, changes in the fair value of the Warrant liability give rise to permanent differences between financial and taxable income.

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2021
Variable Interest Entities [Abstract]
Variable Interest Entities	Note 22 – Variable Interest Entities B ased upon the criteria set forth in ASC 810, the Company consolidates variable interest entities (“VIEs”) in which it has a controlling financial interest and is therefore deemed the primary beneficiary. A controlling financial interest will have both of the following characteristics: (a) the power to direct the VIE activities that most significantly impact economic performance; and (b) the obligation to absorb the VIE losses and the right to receive benefits that are significant to the VIE. The Company has determined that Fathom OpCo meets the definition of a VIE and that the Company is the primary beneficiary of Fathom OpCo beginning on the date of the Business Combination, and therefore the Company must consolidate Fathom OpCo from the date of the Business Combination. The following table presents a summary of the total assets, liabilities, and equity of the Company’s consolidated VIE, which is comprised solely of Fathom OpCo. Period Ended December 31, 2021 (Successor) Fathom OpCo Standalone Total assets $ 1,566,106 Total liabilities 193,437 Total equity 1,372,669

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 23 – Subsequent Events The Company evaluated subsequent events and transactions that occurred after the balance sheet date up to the date that the financial statements were issued. Based upon this review, the Company did not identify any subsequent events that would have required adjustment or disclosure in the consolidated financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements comprise the financial statements of Fathom and its controlled subsidiaries for the nine-day period from December 23, 2021 to December 31, 2021 (the "2021 Successor Period"), the financial statements of Fathom OpCo and its controlled subsidiaries for the period from January 1, 2021 to December 22, 2021 (the "2021 Predecessor Period"), and the financial statements of Fathom OpCo and its controlled subsidiaries for the period from January 1, 2020 to December 31, 2020 (the "2020 Predecessor Period" and, collectively with the 2021 Predecessor Period, the "Predecessor Periods"). The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the accounting and disclosure rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). The consolidated balance sheet as of December 31, 2020 (Predecessor) and the consolidated statement of comprehensive loss for the 2020 Predecessor Period comprise the consolidated financial statements of Fathom OpCo for the same periods which were previously filed within the Company's registration statements files with the SEC, with certain reclassifications on the consolidated balance sheet and consolidated statement of comprehensive loss that were made such that the financial captions between the Successor Period and the Predecessor Periods are comparable. Amounts in the prior years' consolidated financial statements are reclassified whenever necessary to conform to the current year's presentation. The reclassifications had no impact on our results of operations, financial position, or cash flows for the Predecessor Periods. All material intercompany balances have been eliminated in consolidation in each period presented.
Correction of Immaterial Errors	Correction of Immaterial Errors The consolidated financial statements as of and for the 2020 Predecessor Period include the correction of an immaterial error. The correction relates to the misclassification of selling, general, and administrative expense as other expense on the consolidated statement of comprehensive loss for the 2020 Predecessor Period. The correction resulted in an increase to selling, general, and administrative expense of $ 2,511 and a decrease to other expense of $ 2,511 for the 2020 Predecessor Period. The comprehensive loss for the 2020 Predecessor Period was not impacted as a result of the correction of this immaterial error. In addition, the consolidated financial statements as of and for the 2021 Predecessor period include the correction of an immaterial error. The correction relates to the understatement of stock compensation expense in periods prior to the 2021 Predecessor Period. A correcting entry of $ 512 was recorded in the 2021 Predecessor Period statement of comprehensive loss as a prospective correction of the prior period immaterial errors.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company, its controlled subsidiaries, and certain variable interest entities (“VIEs”) where the Company is the primary beneficiary. The Company is deemed to be the primary beneficiary of a VIE when it has both (1) the power to direct the activities of the VIE that most significantly impact the entity’s economic performance, and (2) exposure to benefits and/or losses that could potentially be significant to the entity. Assets and liabilities of VIEs and their respective results of operations are consolidated from the date that the Company became the primary beneficiary through the date that the Company ceases to be the primary beneficiary. Fathom consolidates the accounts of Fathom OpCo since Fathom OpCo has been determined to be a VIE and Fathom is the primary beneficiary of Fathom OpCo.
Business Combination	Business Combination The Company applies the acquisition method to all transactions and other events in which the entity obtains control over one or more other businesses, including the Business Combination, (as defined in Note 3), whereby Fathom was determined to be the primary beneficiary of Fathom OpCo, a VIE. Assets acquired and liabilities assumed are measured at fair value as of the acquisition date. Liabilities related to contingent consideration are recognized at the acquisition date and re-measured at fair value in each subsequent reporting period if the contingent consideration is liability classified. Goodwill is recognized as the excess of the consideration transferred over the fair value of the net identifiable assets acquired. Under Accounting Standards Codification ("ASC") Topic 805 - Business Combinations ("ASC 805"), there is an option to apply push-down accounting, which establishes a new basis for the assets and liabilities of the acquired company based on a “push-down” of the acquirer’s stepped-up basis. The push-down accounting election is made in the reporting period in which the change in control event occurs. Fathom has elected push-down accounting for the Business Combination, and recorded the push-down entries at Fathom OpCo.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Making estimates requires the Company’s management to exercise significant judgment. It is at least reasonably possible that the estimate of the effect of a condition, situation or set of circumstances that existed at the date of the consolidated financial statements, which the Company’s management considered in formulating its estimate, could change in the near term due to one or more future confirming events. Accordingly, the actual results could differ significantly from those estimates.
Income Taxes	Income Taxes The Company accounts for income taxes under ASC Topic 740 - Income Taxes ("ASC 740"), which prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities. The Company is organized as a Delaware C corporation.
Credit Risk, Major Customers, and Suppliers	Credit Risk, Major Customers, and Suppliers The Company extends trade credit to its customers on terms that are generally practiced in the industry. During the 2020 Predecessor Period, the 2021 Predecessor Period, and 2021 Successor Period the Company did not have any customers or suppliers that comprised a significant percentage of the Company’s operations.
Trade Accounts Receivable, Unbilled Revenue and Allowance for Doubtful Accounts	Trade Accounts Receivable, Unbilled Revenue and Allowance for Doubtful Accounts Accounts receivable are stated at net invoice amounts. Unbilled revenue represents receivables due from customers as either the performance obligation has been completed for revenue recognized over time or the product has shipped and the customer invoice has yet to be generated. The balance in unbilled revenue, included in accounts receivable, was $ 0 and $ 173 as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor), respectively. An allowance for doubtful accounts is established based on a specific assessment of all invoices that remain unpaid following normal customer payment periods. In addition, a general valuation allowance is established for the remaining accounts receivable that have not been specifically assessed based on historical loss experience as well as geographic and general economic conditions. All amounts deemed to be uncollectible are charged against the allowance for doubtful accounts in the period that determination is made. The allowance for doubtful accounts on accounts receivable balances was $ 1,150 as of December 31, 2021 (Successor) and $ 649 as of December 31, 2020 (Predecessor).
Inventory	Inventory Inventory is stated at the lower of cost or net realizable value (“NRV”), with NRV based on selling prices in the ordinary course of business, less costs of completion, disposal, and transportation. Costs are determined on the first-in, first-out (“FIFO”) method.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost less accumulated depreciation and amortization. The straight-line method is used for computing depreciation. Assets are depreciated over their estimated useful lives. The cost of leasehold improvements are amortized over the lesser of the length of the related leases or the estimated useful lives of the assets. Costs of maintenance and repairs are charged to expense when incurred. See Note 7 for further information.
Goodwill	Goodwill The Company recognizes goodwill in accordance with ASC Topic 350, Goodwill and Other ("ASC 350"). Goodwill is the excess of costs of an acquired entity over the amounts assigned to assets acquired and liabilities assumed in a business combination. Goodwill is not amortized. During the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period the Company determined that no impairment charges for goodwill were required to be recognized.
Intangible Assets	Intangible Assets Acquired intangible assets subject to amortization are stated at cost and are amortized using the straight-line method over the estimated useful lives of the assets. Intangible assets that are subject to amortization are reviewed for potential impairment whenever events or circumstances indicate that carrying amounts may not be recoverable. During the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, there were no impairments of intangible assets.
New Fathom Units	New Fathom Units In conjunction with the Business Combination, Fathom OpCo restructured its classes of members units whereby, subsequent to the Business Combination, Fathom OpCo's equity consists solely of Class A common units (the "New Fathom Units"). Prior to the Business Combination, Fathom OpCo's members' equity consisted of Class A common units and Class B common units. See Note 14 for further information.
Warrant Liability	Warrant Liability The Company accounts for both the Public Warrants (the "Public Warrants") and Private Placement Warrants (the "Private Placement Warrants") (collectively as the "Warrants") as liability-classified instruments based on an assessment of the Warrants’ specific terms and applicable authoritative guidance per ASC Topic 480, Distinguishing Liabilities from Equity ("ASC 480") and ASC Topic 815, Derivatives and Hedging ("ASC 815"). The assessment considers whether the Warrants are freestanding financial instruments pursuant to ASC 480, whether Warrants meet the definition of a liability pursuant to ASC Topic 480 and whether the Warrants meet all of the requirements for equity classification under ASC 815, including whether the Warrants are indexed to the Company's Class A common stock. This assessment, which requires the use of professional judgment, is conducted at the time of issuance of the Warrants and as of each subsequent quarterly period end date while the Warrants are outstanding. Since both the Public Warrants and Private Placement Warrants are liability-classified, the Warrants are required to be recorded at fair value on the date of issuance and each balance sheet date thereafter. Changes in the fair value of the Warrants are recognized as a non-cash gain or loss on the consolidated statement of comprehensive income (loss). The fair value of the Public Warrants was determined using the closing price of the Public Warrants as of December 31, 2021 (Successor), and the fair value of the Private Placement Warrants was estimated using a Monte Carlo simulation approach. See Note 11 and Note 19 for further information.
Fathom Earnout Shares	Fathom Earnout Shares The Company issued 9,000,000 shares of Class A common stock and New Fathom Units that are subject to certain vesting and transfer restrictions (collectively, the "Fathom Earnout Shares") as part of the Business Combination. The Fathom Earnout Shares vest in three tranches of 3,000,000 shares. The first tranche of the Fathom Earnout Shares vest if the volume weighted average price (“VWAP”) of the Company's Class A common stock with respect to a trading day is greater than or equal to $ 12.50 for any 20 trading days within a consecutive 30 -trading-day period. The second tranche of Fathom Earnout Shares vest if the VWAP of the Company's Class A common stock with respect to a trading day is greater than or equal to $ 15.00 for any 20 trading days within a consecutive 30 -trading-day period. The third tranche of Fathom Earnout Shares vest if the VWAP of the Company's Class A common stock with respect to a trading day is greater than or equal to $ 20.00 for any 20 trading days within a consecutive 30 -trading-day period. The Fathom Earnout Shares were issued as part of the Business Combination and are accounted for as contingent consideration, and thus purchase consideration, and classified as a liability. This classification requires the Company to re-measure the Fathom Earnout Shares at fair value each reporting date. See Note 3 for further information.
Sponsor Earnout Shares	Sponsor Earnout Shares Prior to Altimar II's initial public offering, Altimar II Sponsor, LLC (the "Sponsor") received 8,625,000 Class B Ordinary Shares ("Founder Shares") of the Company in exchange for an investment of $ 25 . In conjunction with the Business Combination, the holders of the Founder Shares forfeited 2,587,500 Founder Shares and received 1,267,500 shares of Class A common stock, (the "Sponsor Earnout Shares" and, together with the Fathom Earnout Shares, the "Earnout Shares") which vest only if the stock price of the Company reaches $ 12.50 for any 20 days within a consecutive 30 -trading-day period. The remaining 4,770,000 Founder Shares were cancelled and replaced with 4,770,000 shares of Class A common stock of the Company which are recorded as equity in the Company's consolidated balance sheet as of December 31, 2021 (Successor) The Company classifies the Sponsor Earnout Shares as a liability measured at fair value upon the consummation of the Business Combination, the date of issuance, and each subsequent reporting date. The Sponsor Earnout Shares are not included as part of the consideration transferred in the Business Combination since the Sponsor Earnout Shares do not represent payments to any of the sellers in the Business Combination.
Noncontrolling Interest	Non-controlling Interest Non-controlling interest represents the Company’s non-controlling interest in consolidated subsidiaries which are not attributable, directly or indirectly, to the controlling Class A common stock ownership of the Company. The Company's comprehensive income in the 2021 Successor Period is reduced by the portion of Fathom OpCo's comprehensive loss that is attributable to noncontrolling interests. The Company's non-controlling interest is representative of the fact that the Company directly owns 37.6 % of Fathom OpCo's New Fathom Units while the holders of the non-controlling interest in Fathom OpCo hold 62.4 %. Since the non-controlling interest may be redeemed for cash and redemption is considered outside of the Company's control, the non-controlling interest is recorded in temporary or "mezzanine" equity on the Consolidated Balance sheet as of December 31, 2021 (Successor). See Note 3 and Note 14 for further information.
Tax Receivable Agreement	Tax Receivable Agreement In connection with the Business Combination, Fathom entered into the Tax Receivable Agreement ("TRA"), which generally provides for the payment by it of 85 % of the net cash savings, if any, in U.S. federal, state and local, income and franchise tax (computed using certain assumptions to address the impact of state and local taxes) that it actually realizes (or in certain cases is deemed to realize) as a result of tax basis in certain assets and other tax attributes. The TRA is a direct obligation of the Company, and not of its subsidiaries. Since the payments under the TRA will be made to selling shareholders of Fathom OpCo, the fair value of the TRA as of the date of the Business Combination is considered part of the consideration transferred as part of the Business Combination with Fathom OpCo. See Note 3 for further information. Subsequent to the initial recognition of the TRA as part of the Business Combination on December 23, 2021, the TRA is recorded at fair value. Any changes in fair value of the TRA subsequent to the Business Combination are recorded as non-cash gains or losses in the Company consolidated statement of comprehensive loss in the 2021 Successor Period. See Note 19 for further information.
Foreign Currency Exchange and Translation	Foreign Currency Exchange and Translation The expression of assets and liabilities in a foreign currency amount gives rise to exchange gains and losses when such obligations are paid in U.S. dollars. Foreign currency exchange rate adjustment (i.e., differences between amounts recorded and actual amounts owed or paid) are reported in the consolidated statements of comprehensive income (loss) as foreign currency fluctuations occur. Foreign currency exchange rate adjustments are reported in the consolidated statements of cash flows using the exchange rates in effect at the time of the cash flows. Assets and liabilities of the Company's operations in China are translated into U.S. dollars at the rate of exchange in effect at the close of the period. Income and expenses are translated at an average rate of exchange for the period. The aggregate effect of translating the financial statements is included in other comprehensive loss. Adjustments to the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period were immaterial.
Fair Value Measurements	Fair Value Measurements The fair value of the Company’s assets and liabilities, which qualify as financial instruments under ASC Topic 820, Fair Value Measurement ("ASC 820"), approximates the carrying amounts represented in the accompanying consolidated balance sheets, primarily due to their short-term nature, except for the Earnout Shares liability and Warrant liabilities, see Note 19 for further information . The framework for determining fair value is based on a hierarchy that prioritizes the inputs and valuation techniques used to measure fair value. There are three levels of inputs that may be used to measure fair value: Fair values determined by Level 1 inputs use quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. Fair values determined by Level 2 inputs use other inputs that are observable, either directly or indirectly. These Level 2 inputs include quoted prices for similar assets and liabilities in active markets and other inputs such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs, including inputs that are available in situations where there is little, if any, market activity for the related asset. These Level 3 fair value measurements are based primarily on management’s own estimates using pricing models, discounted cash flow methodologies, or similar techniques considering the characteristics of the asset. In instances whereby, inputs used to measure fair value fall into different levels in the above fair value hierarchy, fair value measurements in their entirety are categorized based on the lowest level input that is significant to the valuation. The Company’s assessment of the significance of particular inputs to these fair value measurements requires judgment and considers factors specific to each asset or liability.
Debt Issuance Costs	Debt Issuance Costs Debt issuance costs were incurred by Fathom OpCo in connection with obtaining the debt to finance the acquisitions disclosed in Note 4. If such financing is settled or replaced prior to maturity with debt instruments that have substantially different terms, the settlement is treated as an extinguishment and the unamortized costs are charged to gain or loss on extinguishment of debt. If such financing is settled or replaced with debt instruments from the same lender that do not have substantially different terms, the new debt agreement is accounted for as a modification of the prior debt agreement and the unamortized costs remain capitalized, the new original issuance discount costs are capitalized, and any new third-party costs are charged to expense. These costs are recorded as a reduction in the recorded balance of the outstanding debt. The costs are amortized over the term of the related debt and reported as a component of interest expense by using the straight-line method which is not materially different than the effective interest method.
Revenue Recognition	Revenue Recognition The Company accounts for revenue under ASC Topic 606, Revenue from Contracts with Customer's ("ASC 606"). Most of the Company’s revenue has one performance obligation and is recognized on a point-in-time basis upon shipment. The majority of the Company’s injection molding contracts have multiple performance obligations including one obligation to produce the mold and sample part and a second obligation to produce production parts. For injection molding contracts with multiple performance obligations, the Company allocates revenue to each performance obligation based on its relative standalone selling price and recognizes revenue for each performance obligation on a point-in-time basis upon shipment. We generally determine stand-alone selling price based on the price charged to customers. The Company’s payments terms are consistent with industry standards and never exceed 12 months.
Segment Reporting	Segment Reporting In accordance with the Financial Accounting Standards Board's ("FASB") authoritative guidance on segment reporting, the Company has one operating segment and one reportable segment. The Company has one line of business, which is product development and on-demand manufacturing services.
Other Comprehensive Loss	Other Comprehensive Loss U.S. GAAP generally requires that recognized revenue, expenses, gains and losses be included in net income. Certain changes in assets and liabilities, however, such as foreign currency translation adjustments, are reported as a direct adjustment to the equity section of the consolidated balance sheets. Such items, along with net income, are considered components of comprehensive income or loss.
Recent Accounting Pronouncements	Recent Accounting Pronouncements The FASB issued Accounting Standards Update (“ASU”) 2016-02 which is codified in ASC 842, Leases ("ASC 842") and will supersede the current lease requirements in ASC 840 ("ASC 840"). ASC 842 requires lessees to recognize a right-to-use asset and related lease liability for all leases, with a limited exception for short-term leases. Leases will be classified as either finance or operating, with the classification affecting the pattern of expense recognition in the statement of operations. Currently, leases are classified as either capital or operating, with only capital leases recognized on the balance sheet. The new lease guidance will be effective for the Company’s fiscal year ending December 31, 2022 and will be applied using a modified retrospective transition method to either the beginning of the earliest period presented or the beginning of the year of adoption. The new lease standard is expected to have a significant effect on the Company’s financial statements as a result of the Company’s operating leases, that will be reported on the balance sheet at adoption. Upon adoption, the Company will recognize a lease liability and corresponding right-to use asset based on the present value of the minimum lease payments. The effects on the results of operations are not expected to be significant as recognition and measurement of expenses and cash flows for leases will be substantially the same under the new standard. The FASB issued ASU 2016-13, Financial Instruments—Credit Losses: Measurement of Credit Losses on Financial Instruments ("ASC 326"), which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments including trade receivables and available for sale debt securities. ASC 326 is effective for fiscal years beginning after December 15, 2022, with early adoption permitted. In August 2020, the FASB issued Accounting Standards Update No. 2020-06, Debt — Debt with Conversion and Other Options ("Subtopic 470-20") and Derivatives and Hedging — Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity” (“ASU 2020-06”), which simplifies accounting for convertible instruments by removing major separation models required under current GAAP. ASU 2020-06 removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception and it also simplifies the diluted earnings per share calculation in certain areas. ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years, with early adoption permitted. The Company adopted ASU 2020-06 effective as of January 1, 2021. The adoption of ASU 2020-06 did not have an impact on the Company’s financial statements as the Company did not hold convertible instruments prior to January 1, 2021. The Company’s management does not believe that any other recently issued, but not yet effective, accounting standards, if currently adopted, would have a material effect on the Company’s financial statements.

Business Combination with Fat_2

Business Combination with Fathom OpCo (Tables) - Fathom OpCo [Member]	12 Months Ended
	Dec. 31, 2021
Business Acquisition [Line Items]
Schedule of fair value of the total purchase consideration transferred	The Business Combination was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred was $ 1,364,220 . See below for a summary of the total consideration transferred. Total Consideration Transferred: Total cash consideration $ 53,332 Fathom earnout shares 88,160 Class A common stock transferred 375,478 TRA obligations to the sellers 4,300 Total consideration transferred to sellers 521,270 Non-controlling interest 842,950 Fair value of total consideration transferred $ 1,364,220
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair value of the assets acquired and liabilities assumed in connection with the acquisition: Total Assets acquired: Cash and cash equivalents $ 9,577 Accounts receivable, net 25,010 Inventory 12,825 Prepaid expenses 2,336 Other current assets 836 Property and equipment, net 44,397 Goodwill 1,189,464 Intangible assets 270,000 Other assets 2,200 Total assets acquired 1,556,645 Liabilities assumed: Accounts payable 9,808 Taxes payable 71 Accrued expenses 4,860 Current portion - long-term debt 152,000 Deferred revenue 651 Other current liabilities 4,504 Other long-term liabilities 20,531 Total liabilities assumed 192,425 Net identifiable assets acquired $ 1,364,220
Summary of the intangible assets acquired in the acquisition	Identifiable Intangible Assets Provisional fair value Provisional useful life (in years) Trade name $ 70,000 15 Customer relationships 180,000 19 Developed software 4,300 5 Developed technology 15,700 5 $ 270,000
Summary of pro forma information unaudited	Pro Forma Information (Unaudited) Year Ended December 31, 2021 2020 Pro forma revenue $ 162,563 $ 149,405 Pro forma net (loss) ( 14,088 ) ( 17,939 ) Pro forma net (loss) attributable to controlling interest ( 5,297 ) ( 6,745 ) Pro forma net (loss) attributable to non-controlling interest $ ( 8,791 ) $ ( 11,194 )

Fathom OpCo Predecessor Perio_2

Fathom OpCo Predecessor Period Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2021
Incodema And Newchem LLC | Incodema LLC [Member]
Business Acquisition [Line Items]
Summary of Total Purchase Consideration Transferred	The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Incodema Newchem Total Cash $ 30,948 $ 6,320 $ 37,268 Equity instruments 920 183 1,103 Contingent consideration 8,696 - 8,696 Fair value of total consideration transferred $ 40,564 $ 6,503 $ 47,067
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Incodema and Newchem: Acquisition Date Fair Value Recognized amounts of identifiable assets acquired and liabilities assumed Incodema Newchem Cash $ 63 $ 69 Accounts receivable, net 2,370 741 Inventory 735 487 Other current assets 3 1 Prepaid expenses 77 8 Fixed assets, net 2,277 1,949 Intangible assets 19,300 2,800 Total assets acquired 24,825 6,055 Accounts payable 324 223 Accrued expenses 110 35 Other current liabilities 286 61 Total liabilities assumed 720 319 Total identifiable net assets 24,105 5,736 Goodwill $ 16,459 $ 767
Summary of Intangible Assets Acquired in Acquisition	Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value - Incodema Estimated Life (Years) Trade name $ 2,700 15 Customer relationships 11,500 9 Developed software 5,100 5 Total intangible assets $ 19,300 Acquisition Date Fair Value - Newchem Estimated Life (Years) Trade name $ 300 5 Customer relationships 2,500 16 Total intangible assets $ 2,800
Summary of Revenue and Net (Loss) Since Acquisition	The amounts of revenue and net (loss) of Incodema since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 6,900 Net (loss) $ ( 1,085 ) The amounts of revenue and net income of Newchem since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 2,369 Net income $ 184
Daholquist Machine
Business Acquisition [Line Items]
Summary of Total Purchase Consideration Transferred	The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 16,098 Equity instruments 368 Contingent consideration 1,166 Fair value of total consideration transferred $ 17,632
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Dahlquist: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 357 Accounts receivable, net 1,215 Inventory 1,597 Indemnification asset - PPP loan 518 Prepaid expenses 8 Fixed assets, net 3,753 Intangible assets 8,300 Total assets acquired 15,748 Accounts payable 68 Paycheck Protection Program (PPP) loan 518 Accrued expenses 475 Total liabilities assumed 1,061 Total identifiable net assets 14,687 Goodwill $ 2,945
Summary of Intangible Assets Acquired in Acquisition	Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 500 5 Customer relationships 7,800 14 Total intangible assets $ 8,300
Summary of Revenue and Net (Loss) Since Acquisition	The amounts of revenue and net (loss) of Dahlquist since the acquisition date included in the 2020 Predecessor Period consolidated statement of comprehensive loss was a follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 310 Net (loss) $ ( 940 )
Majestic Metals, LLC [Member]
Business Acquisition [Line Items]
Summary of Total Purchase Consideration Transferred	The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 33,557 Equity instruments 1,471 Fair value of total consideration transferred $ 35,028
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ ( 1 ) Accounts receivable, net 2,646 Inventory 1,184 Other current assets 30 Prepaid expenses 201 Fixed assets, net 4,229 Intangible assets 20,100 Total assets acquired 28,389 Accounts payable 244 Accrued expenses 231 Other current liabilities 644 Total liabilities assumed 1,119 Total identifiable net assets 27,270 Goodwill $ 7,758
Summary of Intangible Assets Acquired in Acquisition	Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 1,500 5 Customer relationships 18,600 16 Total intangible assets $ 20,100
Summary of Revenue and Net (Loss) Since Acquisition	The amounts of revenue and net (loss) of Majestic since the acquisition date included in the 2020 Predecessor Period statement of comprehensive loss for the reporting periods are as follows: Period From January 1 - December 31, 2020 (Predecessor) Revenue $ 911 Net (loss) $ ( 1,129 )
Summit [Member]
Business Acquisition [Line Items]
Summary of Total Purchase Consideration Transferred	The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 10,875 Fair value of total consideration transferred $ 10,875
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Summit: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 40 Accounts receivable, net 627 Inventory 339 Fixed assets, net 4,371 Intangible assets 5,000 Total assets acquired 10,377 Accounts payable 40 Deferred revenue 776 Other current liabilities 1,418 Total liabilities assumed 2,234 Total identifiable net assets 8,143 Goodwill $ 2,732
Summary of Intangible Assets Acquired in Acquisition	Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 400 5 Customer relationships 4,600 11 Total intangible assets $ 5,000
Summary of Revenue and Net (Loss) Since Acquisition	The amounts of revenue and net loss of Summit since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Predecessor Period are as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 6,748 Net (loss) $ ( 370 )
P P C [Member]
Business Acquisition [Line Items]
Summary of Total Purchase Consideration Transferred	The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 25,721 Fair value of total consideration transferred $ 25,721
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of PPC: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 162 Accounts receivable, net 899 Inventory 480 Fixed assets, net 2,413 Intangible assets 14,200 Total assets acquired 18,154 Accounts payable 148 Accrued expenses 79 Total liabilities assumed 227 Total identifiable net assets 17,927 Goodwill $ 7,794
Summary of Intangible Assets Acquired in Acquisition	Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 1,100 5 Customer relationships 13,100 17 Total intangible assets $ 14,200
Summary of Revenue and Net (Loss) Since Acquisition	The amounts of revenue and net loss of PPC since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Successor Period is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 6,993 Net (loss) $ ( 34 )
Centex and Laser [Member] | Incodema Holdings LLC
Business Acquisition [Line Items]
Summary of Total Purchase Consideration Transferred	The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Centex Laser Total Cash $ 11,774 $ 6,946 $ 18,720 Fair value of total consideration transferred $ 11,774 $ 6,946 $ 18,720
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Centex and Laser: Acquisition Date Fair Value Centex Laser Recognized amounts of identifiable assets acquired and liabilities assumed Cash $ - $ 68 Accounts receivable, net 1,775 900 Inventory 524 622 Prepaid expenses 108 1 Fixed assets, net 1,787 760 Intangible assets 6,243 3,557 Other assets 1 2 Total assets acquired 10,438 5,910 Accounts payable 252 568 Paycheck Protection Program (PPP) loan 649 - Accrued expenses 271 27 Other current liabilities 23 44 Other noncurrent liabilities 1,234 703 Total liabilities assumed 2,429 1,342 Total identifiable net assets 8,009 4,568 Goodwill $ 3,765 $ 2,378
Summary of Intangible Assets Acquired in Acquisition	Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Estimated Life (Years) Trade name $ 510 5 Customer relationships 5,733 17 Total intangible assets $ 6,243 Acquisition Date Estimated Life (Years) Trade name $ 290 5 Customer relationships 3,267 17 Total intangible assets $ 3,557
Summary of Revenue and Net (Loss) Since Acquisition	The amounts of revenue and net loss of Centex and Laser since the acquisition date included in the consolidated statements of comprehensive loss for the 2021 Predecessor Period and is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 9,642 Net (loss) $ ( 98 )
Micropulse West [Member] | Incodema Holdings LLC
Business Acquisition [Line Items]
Summary of Total Purchase Consideration Transferred	The transaction was accounted for using the acquisition method of accounting and the fair value of the total purchase consideration transferred consisted of the following: Consideration Total Cash $ 12,452 Contingent consideration 1,295 Fair value of total consideration transferred $ 13,747
Schedule of fair values of the assets acquired and liabilities	The following table sets forth the fair values of the assets acquired and liabilities assumed in connection with the acquisition of Micropulse West: Recognized amounts of identifiable assets acquired and liabilities assumed Total Cash $ 70 Accounts receivable, net 866 Inventory 333 Other current assets 10 Fixed assets, net 2,490 Intangible assets 7,000 Total assets acquired 10,769 Accounts payable 139 Accrued expenses 13 Other current liabilities 99 Total liabilities assumed 251 Total identifiable net assets 10,518 Goodwill $ 3,229
Summary of Intangible Assets Acquired in Acquisition	Below is a summary of the intangible assets acquired in the acquisition: Acquisition Date Fair Value Estimated Life (Years) Trade name $ 600 5 Customer relationships 6,400 17 Total intangible assets $ 7,000
Summary of Revenue and Net (Loss) Since Acquisition	The amounts of revenue and net loss of Micropulse West since the acquisition date included in the 2021 Predecessor Period consolidated statement of comprehensive loss is as follows: Period From January 1 - December 22, 2021 (Predecessor) Revenue $ 4,614 Net (loss) $ ( 115 )

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2021
Revenue From Contract With Customer [Abstract]
Schedule of Revenue by Product Line	Revenue by product line for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period was as follows: Period From December 23 - December 31, 2021 January 1 - December 22, 2021 (Predecessor) January 1 - December 31, 2020 (Predecessor) Revenue: Additive Manufacturing $ 567 $ 17,270 $ 19,032 Injection Molding 919 27,968 17,093 CNC Machining 1,372 41,775 9,173 Precision Sheet Metal 1,700 51,751 9,811 Ancillary Product Lines 282 8,592 6,180 Total revenue $ 4,840 $ 147,356 $ 61,289

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2021
Inventory Disclosure [Abstract]
Summary of Inventory	The Company’s inventory consisted of the following at December 31, 2021 (Successor) and December 31, 2020 (Predecessor): December 31, December 31, Finished goods $ 3,506 $ 1,819 Raw materials 4,967 2,277 Work in process 5,368 2,359 Tooling 605 338 14,446 6,793 Allowance for obsolescence ( 1,281 ) ( 468 ) Total $ 13,165 $ 6,325

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Summary of Property and Equipment	Property and equipment consisted of the following as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor): Period Ended December 31, 2021 December 31, 2020 Estimated Useful Life Machinery and equipment $ 33,182 $ 25,214 5 Furniture and fixtures 180 812 2 Computer hardware 499 - 2 Computer software 305 - 2 Property and leasehold improvements 7,180 2,838 3 - 23 Construction in progress 2,859 576 n/a Auto / transportation equipment 454 - 3 Total 44,659 29,440 Accumulated depreciation and amortization ( 132 ) ( 3,054 ) Total $ 44,527 $ 26,386

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Changes in the Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the periods ended December 31, 2021 (Successor) and December 31, 2020 (Predecessor) were as follows: Jan. 1, 2020 (Predecessor) Goodwill acquired during 2020 (Predecessor) Dec. 31, 2020 (Predecessor) Goodwill acquired during 2021 (Predecessor) Dec. 22, 2021 (Predecessor) Goodwill acquired during 2021 (Successor) Dec. 31, 2021 (Successor) Goodwill $ 33,007 $ 30,208 $ 63,215 $ 19,898 $ 83,113 $ 1,189,464 $ 1,189,464
Schedule of Intangible Assets Other Than Goodwill	Intangible assets other than goodwill for the periods ended December 31, 2021 (Successor) and December 31, 2020 (Predecessor) were as follows: Period Ended December 31, 2021 (Successor) Gross Accumulated Amortization Net Useful Life (in years) Trade name $ 70,000 $ 98 $ 69,902 15 Customer relationships 180,000 252 179,748 19 Developed software 4,300 6 4,294 5 Developed technology 15,700 22 15,678 5 Total intangible assets $ 270,000 $ 378 $ 269,622 Period Ended December 31, 2020 (Predecessor) Gross Accumulated Amortization Net Useful Life (in years) Trade name $ 12,200 $ 919 $ 11,281 5 - 15 Customer relationships 67,600 4,448 63,152 5 - 17 Developed software 6,400 720 5,680 5 Developed technology 4,500 1,147 3,353 5 Total intangible assets $ 90,700 $ 7,234 $ 83,466
Schedule of Estimated Amortization Expense	Estimated amortization expense for each of the next five years: Year ended Total 2022 $ 17,280 2023 17,280 2024 17,280 2025 17,280 2026 17,280 Thereafter 183,222 Total $ 269,622

Warrant Liability (Tables)

Warrant Liability (Tables)	12 Months Ended
	Dec. 31, 2021
Warrants And Rights Note Disclosure [Abstract]
Summary of Number of Outstanding Warrants and Fair Value	The below table summarizes the number of outstanding Warrants and the fair value as of the 2021 Successor Period. See Note 19 for further information. Fair Value # of Warrants December 31, 2021 (Successor) Public Warrants $ 7,600 8,625,000 Private Placement Warrants $ 26,300 9,900,000

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The Company’s debt as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor) is as follows: As of December 31, 2021 As of December 31, 2020 Debt Description Interest Rate Amount Interest Rate Amount 2018 Term Loan, as amended $ - 7.75 % $ 29,700 2018 DDTL - 7.75 % 2,990 2020 Term Loan - 3-month LIBOR + 7.50 % 19,401 2020 DDTL - 3-month LIBOR + 7.50 % 40,500 New Credit Agreement Revolver 3.60 % 27,000 - New Credit Agreement Term Loan 3.72 % 125,000 - Total principal long-term debt 92,591 Debt issuance costs ( 1,812 ) ( 1,867 ) PPP and other loans - 2,615 Total debt 150,188 93,339 Less: current portion of long-term debt 29,697 2,853 Long-term debt, net of current portion $ 120,491 $ 90,486
Schedule of Balances of Term Loan	The balance of the Term Loan matures as follows: Year ended Total 2022 $ 3,096 2023 5,982 2024 8,453 2025 7,836 2026 99,633 Thereafter - Total $ 125,000

Other Income and Expense, Net (

Other Income and Expense, Net (Tables)	12 Months Ended
	Dec. 31, 2021
Other Income And Expenses [Abstract]
Schedule Of Other Income and Expense Net	Other Income and expense, net is comprised of the following for the periods ended December 31, 2021 (Successor), December 22, 2021 (Predecessor), and December 31, 2020 (Predecessor): Period From December 23 - December 31, January 1 - December 22, January 1 - December 31, Acquisition expenses $ - $ 4,045 $ 1,254 Transaction expense - 12,515 - Loss on debt extinguishment - 2,031 - Loan prepayment fees - 1,463 - Change in fair value of contingent consideration - - 1,055 Change in fair value of TRA 300 - - Loss on sale of assets - 307 - Other 8 646 1,515 Other expense 308 21,007 3,824 Gain on sale of assets - - ( 214 ) Gain on PPP forgiveness - ( 1,624 ) - Change in fair value of Sponsor Earnout Shares ( 3,400 ) - - Change in fair value of contingent consideration ( 23,860 ) ( 3,550 ) - Change in fair value of Warrants ( 8,200 ) - - Other - - ( 371 ) Other income ( 35,460 ) ( 5,174 ) ( 585 ) Other (income) and expense, net $ ( 35,152 ) $ 15,833 $ 3,239

Share Based Compensation (Table

Share Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
2021 Omnibus Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of the activity in the plan	The following table summarizes the activity related to awards issued by the Company in the 2021 Successor Period under the 2021 Omnibus Plan. Successor Shares Weighted Average Grant Date Fair Value Non-vested at December 23, 2021 - - Granted 6,472,617 $ 8.21 Vested - - Forfeited - - Non-vested at December 31, 2021 6,472,617 $ 8.21
Twenty Twenty Activity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of the activity in the plan	A summary of the activity in the plan for the 2020 Predecessor Period is as follows: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2020 4,000 $ 515.09 Granted 5,356 358.15 Vested ( 313 ) 570.20 Forfeited - - Non-vested at December 31, 2020 9,043 $ 420.02
Twenty Twenty One Activity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of the activity in the plan	A summary of the activity in the plans for the 2021 Predecessor Period is as follows: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2021 9,043 $ 420.02 Granted 14,346 1,529.06 Vested ( 1,115 ) 1,930.42 Forfeited ( 10,706 ) 888.81 Non-vested at December 22, 2021 11,568 $ 1,217.42

Earnings Per Share and Earnin_2

Earnings Per Share and Earnings Per Unit (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Unit [Abstract]
Schedule of Basic Earnings Per Share	The Company's basic earnings per share calculation is as follows: Period From December 23 - December 31, Class A Basic Earnings Per Share: Numerator Net income $ 33,470 Less: Net loss attributable to non-controlling interests ( 968 ) Net income attributable to Class A common stock $ 34,438 Denominator Weighted average shares of Class A common stock outstanding-basic 50,785,656 Basic Earnings Per Share $ 0.68
Schedule of Diluted Earnings Per Share	The Company's diluted earnings per share calculation is as follows: Period From December 23 - December 31, Class A Diluted Earnings Per Share: Numerator Net income attributable to holders of Class A common stock $ 33,470 Denominator Weighted average shares of Class A common stock outstanding-basic 50,785,656 Effect of Dilutive Securities Assumed exchange for shares of Class A common stock 85,054,317 Weighted average shares of Class A common stock outstanding-diluted 135,839,973 Diluted Earnings Per Share $ 0.25
Schedule Of Earnings Per Share, Basic and Diluted	Period From January 1 - December 23, January 1 - December 23, Class A Class B Basic and Diluted Earnings Per Unit: Numerator Net (loss) $ ( 11,690 ) $ ( 4,784 ) Less: annual dividends on redeemable preferred units ( 6,582 ) ( 2,694 ) Net (loss) attributable to common unitholders $ ( 18,272 ) $ ( 7,478 ) Denominator Weighted-average units used to compute basic earnings per unit 5,480,611 2,242,981 Basic and Diluted Earnings Per Unit $ ( 3.33 ) $ ( 3.33 ) Period From January 1 - December 31, January 1 - December 31, Class A Class B Basic and Diluted Earnings Per Unit: Numerator Net (loss) $ ( 5,380 ) $ ( 2,583 ) Less: annual dividends on redeemable preferred units ( 4,083 ) ( 1,961 ) Net (loss) attributable to common unitholders $ ( 9,463 ) $ ( 4,544 ) Denominator Weighted-average units used to compute basic earnings per unit 3,531,681 1,696,135 Basic and Diluted Earnings Per Unit $ ( 2.68 ) $ ( 2.68 )

Shareholders' Equity, Noncont_2

Shareholders' Equity, Noncontrolling Interest, and Members' Equity (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Schedule Of Calculation Of Comprehensive Loss Attributable To Non-controlling Interest Holders	The table below demonstrates the calculation of the comprehensive loss attributable to the non-controlling interest holders for the 2021 Successor Period. Period From December 23 - December 31, Fathom OpCo comprehensive loss $ ( 1,551.00 ) Noncontrolling interest percentage 62.4 % Comprehensive loss attributable to noncontrolling interest $ ( 968.00 )
Summary Of Members Equity	The following table represents a summary of the Company’s Members' Equity as of December 31, 2020 (Predecessor): December 31 Class A common units 5,480,611 Class B common units 2,242,981

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases, Operating [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The Company determines if an arrangement is a lease at inception. Operating leases are off balance sheet arrangements with rent expense included in Cost of revenue and Selling, general and administrative in the consolidated statements of comprehensive income (loss). Future noncancelable operating lease commitments are as follows: Year ended Total 2022 $ 3,212 2023 3,027 2024 1,959 2025 1,253 2026 443 Thereafter 328 Total future lease payments $ 10,222

Fathom OpCo Class A Contingen_2

Fathom OpCo Class A Contingently Redeemable Preferred Units (Tables)	12 Months Ended
	Dec. 31, 2021
Temporary Equity Disclosure [Abstract]
Schedule Of Class A Contingently Redeemable Preferred Units Issued and Outstanding	Fathom OpCo had the following contingently redeemable preferred units issued and outstanding at December 31, 2020 (Predecessor): Shares Authorized Shares Issued and Outstanding Original Issue Price Carrying Value Accumulated Unpaid Dividends Amount Contingently Redeemable Class A Preferred Units 1,167,418 1,167,418 $ 46.35 $ 54,105 $ 9,253 $ 63,358

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule Of Fair Value Measurement Of Assets And Liabilities Based On Hierarchy	The following table presents information about the Company’s liabilities that are measured at fair value on a recurring basis as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor) and indicates the fair value hierarchy of the valuation inputs the Company utilized to determine such fair value: Period Ended Description Level December 31, 2021 December 31, 2020 Liabilities: Tax receivable agreement 3 $ 4,600 $ - Legacy Fathom OpCo acquisitions contingent consideration 3 3,598 11,439 Sponsor earnout shares liability 3 9,380 - Fathom earnout shares liability 3 64,300 - Warrant liability – Public Warrants 1 7,600 - Warrant liability – Private Placement Warrants 3 26,300 - $ 115,778 $ 11,439
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	Period Ended December 31, 2021 (Successor) December 31, 2020 (Predecessor) Balance of recurring Level 3 liabilities at beginning of period $ 141,438 $ - Total gains or losses for the period: Included in earnings (income) loss ( 33,260 ) 1,055 Issuances - 11,737 Payments - ( 1,353 ) Transfers into level 3 - - Transfers out of level 3 - - Balance of recurring level 3 liabilities at end of period $ 108,178 $ 11,439

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Summary of Income Tax Expense (Benefit)	Significant components of the Company’s tax expense (benefit) for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, are as follows: Period From December 23 - December 31, 2021 (Successor) January 1 - December 22, 2021 (Predecessor) January 1 - December 31, 2020 (Predecessor) Current expense State $ - $ 52 $ - Federal - - - Subtotal - 52 - Deferred tax benefit State ( 1 ) ( 297 ) - Federal ( 2 ) ( 2,963 ) - Subtotal ( 3 ) ( 3,260 ) - Total $ ( 3 ) $ ( 3,208 ) $ -
Reconciliation of the Expected Statutory Federal Tax and the Total Income Tax Expense (Benefit)	A reconciliation of the expected statutory federal tax and the total income tax expense (benefit) for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period, are as follows: Period From December 23 - December 31, 2021 (Successor) January 1 - December 22, 2021 (Predecessor) January 1 - December 31, 2020 (Predecessor) Federal statutory rate ( 21 %) $ 7,028 $ ( 4,133 ) $ ( 1,672 ) State income taxes, net of federal benefit ( 38 ) ( 245 ) - Pre-closing income held in flow-through entities - 4,133 1,672 Change in tax status of corporate subsidiaries - ( 2,963 ) - Non-controlling interest in Fathom Holdco, LLC 222 - - Remeasurement of Fathom and Sponsor earnout shares ( 5,724 ) Remeasurement of TRA and warrant liability ( 1,662 ) - - Valuation allowance 171 - - Total $ ( 3 ) $ ( 3,208 ) $ -
Summary of Tax Effect of Temporary Differences to Deferred Tax Assets and Liabilities	The tax effect of temporary differences that give rise to deferred tax assets and liabilities for the 2021 Successor Period, 2021 Predecessor Period, and 2020 Predecessor Period are as follows: Period Ended December 31, 2021 (Successor) December 31, 2020 (Predecessor) Deferred tax assets Net operating losses $ 1,494 $ - Transaction costs 861 Interest expense carryforwards 762 Valuation allowance ( 3,117 ) - Total deferred tax assets - - Deferred tax liabilities Investment in Fathom Holdco, LLC ( 17,570 ) - Total deferred tax liabilities ( 17,570 ) - Total net deferred tax liabilities $ ( 17,570 ) $ -

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2021
Variable Interest Entities [Abstract]
Summary of Total Assets, Liabilities, and Equity of the Company's Consolidated VEI	The following table presents a summary of the total assets, liabilities, and equity of the Company’s consolidated VIE, which is comprised solely of Fathom OpCo. Period Ended December 31, 2021 (Successor) Fathom OpCo Standalone Total assets $ 1,566,106 Total liabilities 193,437 Total equity 1,372,669

Nature of Business - Additional

Nature of Business - Additional Information (Details) - Equity Interest [Member]	12 Months Ended
	Dec. 31, 2021
MCT Group Holdings LLC
Nature Of Business [Line Items]
Ownership Interest	100.00%
Incodema Holdings LLC
Nature Of Business [Line Items]
Ownership Interest	100.00%

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Details)		Dec. 31, 2021USD ($)shares	Dec. 31, 2021USD ($)Tranche$ / sharesshares	Dec. 22, 2021USD ($)	Dec. 31, 2020USD ($)shares
Accounting Policies [Line Items]
Contingent consideration	[1]	$ 2,748,000	$ 2,748,000		$ 4,066,000
Accounts receivable, net	[1]	25,367,000	25,367,000		15,563,000
Property and equipment, net	[1]	44,527,000	44,527,000		26,386,000
Other non-current assets	[1]	2,036,000	2,036,000		1,038,000
Accounts payable	[1],[2]	9,409,000	9,409,000		4,404,000
Other non-current liabilities	[1]	4,655,000	4,655,000		514,000
Long-term contingent consideration	[1]	850,000	850,000		7,373,000
Selling, general, and administrative expense	[3],[4]	3,133,000		$ 37,507,000	24,642,000
Depreciation and amortization	[4]	416,000		10,357,000	4,672,000
Other expense	[4]	308,000		21,007,000	3,824,000
Accounts receivable, allowance for credit loss		1,150,000	$ 1,150,000		649,000
Goodwill, Impairment Loss		0		0	0
Impairments of intangible assets		$ 0		0	$ 0
Number of tranches | Tranche			3
Earnout shares vested | shares			3,000,000
Percentage of net cash savings payment to tax receivable agreement			85.00%
Fathom OpCo
Accounting Policies [Line Items]
Noncontrolling interest, ownership percentage		62.40%	62.40%
Noncontrolling interest, ownership percentage by noncontrolling owners		37.60%	37.60%
Altimar II Sponsor, LLC [Member]
Accounting Policies [Line Items]
Shares granted, shares, share-based payment arrangement, forfeited | shares			2,587,500
Number of remaining founder shares cancelled | shares			4,770,000
Class A Common Stock [Member]
Accounting Policies [Line Items]
Common stock issued | shares		50,785,656	50,785,656
Class A Common Stock [Member] | Altimar II Sponsor, LLC [Member]
Accounting Policies [Line Items]
Volume weighted average price | $ / shares			$ 12.50
Earnout shares trading days			20 days
Earnout shares consecutive trading days			30 days
Issuance of share to Sponsor | shares			4,770,000
Shares granted, shares, share-based payment arrangement, issued | shares			1,267,500
Class A Common Stock [Member] | First Tranche [Member]
Accounting Policies [Line Items]
Volume weighted average price | $ / shares			$ 12.50
Earnout shares trading days			20 days
Earnout shares consecutive trading days			30 days
Class A Common Stock [Member] | Second Tranche [Member]
Accounting Policies [Line Items]
Volume weighted average price | $ / shares			$ 15
Earnout shares trading days			20 days
Earnout shares consecutive trading days			30 days
Class A Common Stock [Member] | Third Tranche [Member]
Accounting Policies [Line Items]
Volume weighted average price | $ / shares			$ 20
Earnout shares trading days			20 days
Earnout shares consecutive trading days			30 days
Class A Common Stock [Member] | Fathom Earnout Shares [Member]
Accounting Policies [Line Items]
Common stock issued | shares		9,000,000	9,000,000
Class B Common Stock [Member]
Accounting Policies [Line Items]
Common stock issued | shares		84,294,971	84,294,971
Shares granted, shares, share-based payment arrangement, issued | shares	[5]				294,529
Class B Common Stock [Member] | Altimar II Sponsor, LLC [Member]
Accounting Policies [Line Items]
Issuance of share to Sponsor | shares			8,625,000
Stock issued during period, value			$ 25,000,000
Unbilled Revenues [Member]
Accounting Policies [Line Items]
Unbilled Contracts Receivable		$ 0	$ 0		$ 173,000
Correction of Immaterial Errors [Member]
Accounting Policies [Line Items]
Selling, general, and administrative expense					2,511,000
Other expense					$ (2,511,000)
Comprehensive income (loss)				$ 512,000
[1]	See accompanying notes to the consolidated financial statements.
[2]	Inclusive of accounts payable to related parties of $ 1,246 and $ 541 as of December 31, 2021 (Successor) and December 31, 2020 (Predecessor), respectively.
[3]	Inclusive of $ 0 , $ 1,723 , and $ 722 of management fees incurred to a related party for the periods ended December 23 - 31, 2021, January 1 - December 22, 2021, and January 1 - December 31 2020, respectively. See Note 17.
[4]	See accompanying notes to the consolidated financial statements.
[5]	See accompanying notes to the consolidated financial statements.

Business Combination with Fat_3

Business Combination with Fathom OpCo - Additional Information (Details) $ / shares in Units, $ in Thousands	Dec. 23, 2021USD ($)VoteTranche$ / sharesshares	Jan. 01, 2020	Dec. 31, 2021USD ($)Trancheshares	Dec. 22, 2021USD ($)	Dec. 31, 2020USD ($)
Business Acquisition [Line Items]
Number of votes per share | Vote	1
Business combination acquisition costs expensed	$ 19,010
Weighted average amortization period		16 years 10 months 24 days
Number of tranches | Tranche			3
Earnout shares vested | shares			3,000,000
Deferred tax liability recognized			$ 17,570
Fathom OpCo [Member]
Business Acquisition [Line Items]
Business Combination agreement date			Dec. 23, 2021
Business combination acquisition costs expensed	27,397
Deferred tax liability recognized	$ 17,573
Fair value of total purchase consideration transferred			$ 1,364,220
Business combination provisional information initial accounting adjustment accounting incomplete adjustment inventory			0		2,626
Business combination provisional information initial accounting incomplete adjustment intangibles			25,759		19,325
Business combination provisional information initial accounting incomplete adjustment financial liabilities			(6,766)		1,379
Adjustment to stock-based compensation expense			(1,595)		1,595
Adjustments to transaction-related costs			(7,984)		$ 7,984
Fathom OpCo [Member] | Class A Common Stock [Member]
Business Acquisition [Line Items]
Seller earnout contingent consideration			$ 9,000,000
Number of tranches | Tranche	3
Earnout shares vested | shares	3,000,000
Earnout period	5 years
Fathom OpCo [Member] | Class A Common Stock [Member] | First Tranche [Member]
Business Acquisition [Line Items]
Volume weighted average share price thresholds | $ / shares	$ 12.50
Fathom OpCo [Member] | Class A Common Stock [Member] | Second Tranche [Member]
Business Acquisition [Line Items]
Volume weighted average share price thresholds | $ / shares	15
Fathom OpCo [Member] | Class A Common Stock [Member] | Third Tranche [Member]
Business Acquisition [Line Items]
Volume weighted average share price thresholds | $ / shares	$ 20
Fathom OpCo [Member] | Class A Common Stock [Member] | Public investors, PIPE Investors and Founders [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired	10.40%
Fathom OpCo [Member] | Class A Common Stock [Member] | CORE Investors and Other Legacy Fathom Owners [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired	89.60%
Fathom OpCo [Member] | Commitment and Success Fees [Member]
Business Acquisition [Line Items]
Business combination acquisition costs expensed				$ 14,882
Fathom OpCo [Member] | Non Contingent [Member]
Business Acquisition [Line Items]
Business combination acquisition costs expensed				$ 12,515

Business Combination with Fat_4

Business Combination with Fathom OpCo - Schedule of Fair Value of the Total Purchase Consideration Transferred (Details) - Fathom OpCo [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Business Acquisition [Line Items]
Total cash consideration	$ 53,332
Fathom earnout shares	88,160
Class A common stock transferred	375,478
TRA obligations to the sellers	4,300
Total consideration transferred to sellers	521,270
Non-controlling interest	842,950
Fair value of total consideration transferred	$ 1,364,220

Business Combination with Fat_5

Business Combination with Fathom OpCo - Schedule of Fair Values of the Assets Acquired and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021	Dec. 31, 2020	[1]	Jan. 01, 2020	Dec. 31, 2019
Assets acquired:
Goodwill	$ 1,189,464	[1]	$ 83,113	$ 63,215			$ 33,007
Intangible assets						$ 270,000
Fathom OpCo [Member]
Assets acquired:
Cash and cash equivalents	9,577
Accounts receivable, net	25,010
Inventory	12,825
Prepaid expenses	2,336
Other current assets	836
Property and equipment, net	44,397
Goodwill	1,189,464
Intangible assets	270,000
Other assets	2,200
Total assets acquired	1,556,645
Liabilities assumed:
Accounts payable	9,808
Taxes payable	71
Accrued expenses	4,860
Current portion - long-term debt	152,000
Deferred revenue	651
Other current liabilities	4,504
Other Long-term Liabilities	20,531
Total liabilities assumed	192,425
Total identifiable net assets	$ 1,364,220
[1]	See accompanying notes to the consolidated financial statements.

Business Combination with Fat_6

Business Combination with Fathom OpCo - Summary of Intangible Assets Acquired in the Acquisition (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Provisional fair value	$ 270,000
Trade Name [Member]
Business Acquisition [Line Items]
Provisional useful life		15 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Provisional useful life		19 years
Developed Technology [Member]
Business Acquisition [Line Items]
Provisional useful life		5 years	5 years
Fathom OpCo [Member]
Business Acquisition [Line Items]
Provisional fair value		$ 270,000
Fathom OpCo [Member] | Trade Name [Member]
Business Acquisition [Line Items]
Provisional fair value	$ 70,000
Provisional useful life	15 years
Fathom OpCo [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Provisional fair value	$ 180,000
Provisional useful life	19 years
Fathom OpCo [Member] | Developed Software [Member]
Business Acquisition [Line Items]
Provisional fair value	$ 4,300
Provisional useful life	5 years
Fathom OpCo [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Provisional fair value	$ 15,700
Provisional useful life	5 years

Business Combination with Fat_7

Business Combination with Fathom OpCo - Summary of Pro Forma Information (Unaudited) (Details) - Fathom OpCo [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Pro forma revenue	$ 162,563	$ 149,405
Pro forma net (loss)	(14,088)	(17,939)
Pro forma net (loss) attributable to controlling interest	(5,297)	(6,745)
Pro forma net (loss) attributable to noncontrolling interest	$ (8,791)	$ (11,194)

Fathom OpCo Predecessor Perio_3

Fathom OpCo Predecessor Period Acquisitions - Incodema and Newchem - Additional Information (Details) - USD ($) $ in Thousands		Dec. 23, 2021	Jul. 27, 2020	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2020
Business Acquisition [Line Items]
Business combination acquisition costs expensed		$ 19,010
Contingent consideration paid				$ 1,984
Remaining undiscounted payments under contingent consideration arrangement	[1]			2,748			$ 4,066
Remaining undiscounted payments under contingent consideration arrangement	[1]			$ 850			$ 7,373
Incodema, LLC and Newchem, LLC [Member] | Incodema LLC [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired			100.00%
Business combination acquisition costs expensed			$ 1,489
Payment of transaction fee to affiliate			$ 400
Incodema [Member]
Business Acquisition [Line Items]
Remaining undiscounted payments under contingent consideration arrangement					$ 850	$ 2,720
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Perio_4

Fathom OpCo Predecessor Period Acquisitions - Incodema and Newchem - Summary of Total Purchase Consideration Transferred (Details) $ in Thousands	Jul. 27, 2020USD ($)
Incodema LLC [Member]
Business Acquisition [Line Items]
Cash	$ 30,948
Equity instruments	920
Contingent consideration	8,696
Fair value of total consideration transferred	40,564
Newchem, LLC [Member]
Business Acquisition [Line Items]
Cash	6,320
Equity instruments	183
Fair value of total consideration transferred	6,503
Incodema, LLC and Newchem, LLC [Member]
Business Acquisition [Line Items]
Cash	37,268
Equity instruments	1,103
Contingent consideration	8,696
Fair value of total consideration transferred	$ 47,067

Fathom OpCo Predecessor Perio_5

Fathom OpCo Predecessor Period Acquisitions - Incodema and Newchem - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	[1]	Dec. 22, 2021	Dec. 31, 2020	[1]	Jul. 27, 2020	Jan. 01, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Intangible assets							$ 270,000
Goodwill	$ 1,189,464		$ 83,113	$ 63,215				$ 33,007
Incodema LLC [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash						$ 63
Accounts receivable, net						2,370
Inventory						735
Other current assets						3
Prepaid expenses						77
Fixed assets, net						2,277
Intangible assets						19,300
Total assets acquired						24,825
Accounts payable						324
Accrued expenses						110
Other current liabilities						286
Total liabilities assumed						720
Total identifiable net assets						24,105
Goodwill						16,459
Newchem, LLC [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash						69
Accounts receivable, net						741
Inventory						487
Other current assets						1
Prepaid expenses						8
Fixed assets, net						1,949
Intangible assets						2,800
Total assets acquired						6,055
Accounts payable						223
Accrued expenses						35
Other current liabilities						61
Total liabilities assumed						319
Total identifiable net assets						5,736
Goodwill						$ 767
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Perio_6

Fathom OpCo Predecessor Period Acquisitions - Incodema and Newchem - Summary of Intangible Assets Acquired in Acquisition (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Jul. 27, 2020
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 3,557
Incodema LLC [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 19,300
Incodema LLC [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 2,700
Estimated Life (Years)		15 years
Incodema LLC [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 11,500
Estimated Life (Years)		9 years
Incodema LLC [Member] | Developed Software
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 5,100
Estimated Life (Years)		5 years
Newchem, LLC [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 2,800
Newchem, LLC [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 300
Estimated Life (Years)		5 years
Newchem, LLC [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 2,500
Estimated Life (Years)		16 years

Fathom OpCo Predecessor Perio_7

Fathom OpCo Predecessor Period Acquisitions - Incodema and Newchem - Summary of Revenue and Net (Loss) Income Since Acquisition (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Incodema LLC [Member]
Business Acquisition [Line Items]
Revenue	$ 6,900
Net (loss) income	(1,085)
Newchem, LLC [Member]
Business Acquisition [Line Items]
Revenue	2,369
Net (loss) income	$ 184

Fathom OpCo Predecessor Perio_8

Fathom OpCo Predecessor Period Acquisitions - Dahlquist - Additional Information (Details) - USD ($) $ in Thousands		Dec. 23, 2021	Dec. 16, 2020	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Business combination acquisition costs expensed		$ 19,010
Contingent consideration paid				$ 1,984
Remaining undiscounted payments under contingent consideration arrangement	[1]			2,748	$ 4,066
Dahlquist Machine, LLC [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired			100.00%
Business combination acquisition costs expensed					$ 804
Payment of transaction fee to affiliate			$ 252
Contingent consideration paid				$ 2,600
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Perio_9

Fathom OpCo Predecessor Period Acquisitions - Dahlquist - Summary of Total Purchase Consideration Transferred (Details) - Dahlquist Machine, LLC [Member] $ in Thousands	Dec. 16, 2020USD ($)
Business Acquisition [Line Items]
Cash	$ 16,098
Equity instruments	368
Contingent consideration	1,166
Fair value of total consideration transferred	$ 17,632

Fathom OpCo Predecessor Peri_10

Fathom OpCo Predecessor Period Acquisitions - Dahlquist - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	[1]	Dec. 22, 2021	Dec. 31, 2020	[1]	Dec. 16, 2020	Jan. 01, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Intangible assets							$ 270,000
Goodwill	$ 1,189,464		$ 83,113	$ 63,215				$ 33,007
Dahlquist Machine, LLC [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash						$ 357
Accounts receivable, net						1,215
Inventory						1,597
Indemnification asset - PPP Loan						518
Prepaid expenses						8
Fixed assets, net						3,753
Intangible assets						8,300
Total assets acquired						15,748
Accounts payable						68
Paycheck Protection Program (PPP) loan						518
Accrued expenses						475
Total liabilities assumed						1,061
Total identifiable net assets						14,687
Goodwill						$ 2,945
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_11

Fathom OpCo Predecessor Period Acquisitions - Dahlquist - Summary of Intangible Assets Acquired in Acquisition (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Dec. 16, 2020	Dec. 31, 2021
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 3,557
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)			15 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)			19 years
Dahlquist Machine, LLC [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 8,300
Dahlquist Machine, LLC [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 500
Estimated Life (Years)		5 years
Dahlquist Machine, LLC [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 7,800
Estimated Life (Years)		14 years

Fathom OpCo Predecessor Peri_12

Fathom OpCo Predecessor Period Acquisitions - Dahlquist - Summary of Revenue and Net (Loss) Income Since Acquisition (Details) - Dahlquist Machine, LLC [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Business Acquisition [Line Items]
Revenue	$ 310
Net (loss)	$ (940)

Fathom OpCo Predecessor Peri_13

Fathom OpCo Predecessor Period Acquisitions - Majestic - Additional Information (Details) - USD ($) $ in Thousands	Dec. 23, 2021	Dec. 17, 2020
Business Acquisition [Line Items]
Business combination acquisition costs expensed	$ 19,010
Majestic Metals, LLC [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired		100.00%
Business acquisition, transaction fee		$ 361
Majestic Metals, LLC [Member] | Other Expense [Member]
Business Acquisition [Line Items]
Payment of transaction fee to affiliate		$ 1,145

Fathom OpCo Predecessor Peri_14

Fathom OpCo Predecessor Period Acquisitions - Majestic - Summary of Total Purchase Consideration Transferred (Details) - Majestic Metals, LLC [Member] $ in Thousands	Dec. 17, 2020USD ($)
Business Acquisition [Line Items]
Cash	$ 33,557
Equity instruments	1,471
Fair value of total consideration transferred	$ 35,028

Fathom OpCo Predecessor Peri_15

Fathom OpCo Predecessor Period Acquisitions - Majestic - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	[1]	Dec. 22, 2021	Dec. 31, 2020	[1]	Dec. 17, 2020	Jan. 01, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Intangible assets							$ 270,000
Goodwill	$ 1,189,464		$ 83,113	$ 63,215				$ 33,007
Majestic Metals, LLC [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash						$ 1
Accounts receivable, net						2,646
Inventory						1,184
Other current assets						30
Prepaid expenses						201
Fixed assets, net						4,229
Intangible assets						20,100
Total assets acquired						28,389
Accounts payable						244
Accrued expenses						231
Other current liabilities						644
Total liabilities assumed						1,119
Total identifiable net assets						27,270
Goodwill						$ 7,758
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_16

Fathom OpCo Predecessor Period Acquisitions - Majestic - Summary of Intangible Assets Acquired in Acquisition (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Dec. 17, 2020	Dec. 31, 2021	Jan. 01, 2020
Finite Lived Intangible Assets [Line Items]
Intangible assets				$ 270,000
Acquisition Date Fair Value	$ 3,557
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)			15 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)			19 years
Majestic Metals, LLC [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets		$ 20,100
Acquisition Date Fair Value		20,100
Majestic Metals, LLC [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 1,500
Estimated Life (Years)		5 years
Majestic Metals, LLC [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 18,600
Estimated Life (Years)		16 years

Fathom OpCo Predecessor Peri_17

Fathom OpCo Predecessor Period Acquisitions - Majestic - Summary of Revenue and Net (Loss) Income Since Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Business Acquisition [Line Items]
Revenue	$ 4,840		$ 147,356		$ 61,289
Net income (loss)	$ 34,438	[1]	$ (16,474)	[2]	(7,963)	[2]
Majestic Metals, LLC [Member]
Business Acquisition [Line Items]
Revenue					911
Net (loss)					$ (1,129)
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_18

Fathom OpCo Predecessor Period Acquisitions - Summit - Additional Information (Details) - USD ($) $ in Thousands	Dec. 23, 2021	Feb. 01, 2021
Business Acquisition [Line Items]
Business combination acquisition costs expensed	$ 19,010
Summit [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired		100.00%
Business combination acquisition costs expensed		$ 892
Payment of transaction fee to affiliate		$ 225

Fathom OpCo Predecessor Peri_19

Fathom OpCo Predecessor Period Acquisitions - Summit - Summary of Total Purchase Consideration Transferred (Details) - Summit [Member] $ in Thousands	Feb. 01, 2021USD ($)
Business Acquisition [Line Items]
Cash	$ 10,875
Fair value of total consideration transferred	$ 10,875

Fathom OpCo Predecessor Peri_20

Fathom OpCo Predecessor Period Acquisitions - Summit - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	[1]	Dec. 22, 2021	Feb. 01, 2021	Dec. 31, 2020	[1]	Jan. 01, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Intangible assets							$ 270,000
Goodwill	$ 1,189,464		$ 83,113		$ 63,215			$ 33,007
Summit [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash				$ 40
Accounts receivable, net				627
Inventory				339
Fixed assets, net				4,371
Intangible assets				5,000
Total assets acquired				10,377
Accounts payable				40
Deferred revenue				776
Other current liabilities				1,418
Total liabilities assumed				2,234
Total identifiable net assets				8,143
Goodwill				$ 2,732
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_21

Fathom OpCo Predecessor Period Acquisitions - Summit - Summary of Intangible Assets Acquired in Acquisition (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Feb. 01, 2021	Dec. 31, 2021	Jan. 01, 2020
Finite Lived Intangible Assets [Line Items]
Intangible assets				$ 270,000
Acquisition Date Fair Value	$ 3,557
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)			15 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)			19 years
Summit [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets		$ 5,000
Acquisition Date Fair Value		5,000
Summit [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 400
Estimated Life (Years)		5 years
Summit [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value		$ 4,600
Estimated Life (Years)		11 years

Fathom OpCo Predecessor Peri_22

Fathom OpCo Predecessor Period Acquisitions - Summit - Summary of Revenue and Net (Loss) Income Since Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Business Acquisition [Line Items]
Revenue	$ 4,840		$ 147,356		$ 61,289
Net Income Attributable to Fathom Digital Manufacturing	$ 34,438	[1]	(16,474)	[2]	$ (7,963)	[2]
Summit [Member]
Business Acquisition [Line Items]
Revenue			6,748
Net (loss)			$ (370)
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_23

Fathom OpCo Predecessor Period Acquisitions - PPC - Additional Information (Details) - USD ($) $ in Thousands	Dec. 23, 2021	Apr. 30, 2021
Business Acquisition [Line Items]
Business combination acquisition costs expensed	$ 19,010
P P C [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired		100.00%
Business combination acquisition costs expensed		$ 984
Payment of transaction fee to affiliate		$ 264

Fathom OpCo Predecessor Peri_24

Fathom OpCo Predecessor Period Acquisitions - PPC - Summary of Total Purchase Consideration Transferred (Details) - P P C [Member] $ in Thousands	Apr. 30, 2021USD ($)
Business Acquisition [Line Items]
Cash	$ 25,721
Fair value of total consideration transferred	$ 25,721

Fathom OpCo Predecessor Peri_25

Fathom OpCo Predecessor Period Acquisitions - PPC - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	[1]	Dec. 22, 2021	Apr. 30, 2021	Dec. 31, 2020	[1]	Jan. 01, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Intangible assets							$ 270,000
Goodwill	$ 1,189,464		$ 83,113		$ 63,215			$ 33,007
P P C [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash				$ 162
Accounts receivable, net				899
Inventory				480
Fixed assets, net				2,413
Intangible assets				14,200
Total assets acquired				18,154
Accounts payable				148
Accrued expenses				79
Total liabilities assumed				227
Total identifiable net assets				17,927
Goodwill				$ 7,794
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_26

Fathom OpCo Predecessor Period Acquisitions - PPC - Summary of Intangible Assets Acquired in Acquisition (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Dec. 31, 2021	Jan. 01, 2020
Finite Lived Intangible Assets [Line Items]
Intangible assets			$ 270,000
Acquisition Date Fair Value	$ 3,557
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		15 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		19 years
P P C [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets	14,200
Acquisition Date Fair Value	14,200
P P C [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 1,100
Estimated Life (Years)	5 years
P P C [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 13,100
Estimated Life (Years)	17 years

Fathom OpCo Predecessor Peri_27

Fathom OpCo Predecessor Period Acquisitions - PPC - Summary of Revenue and Net (Loss) Income Since Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Business Acquisition [Line Items]
Revenue	$ 4,840		$ 147,356		$ 61,289
Net income (loss)	$ 34,438	[1]	(16,474)	[2]	$ (7,963)	[2]
P P C [Member]
Business Acquisition [Line Items]
Revenue			6,993
Net (loss)			$ (34)
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_28

Fathom OpCo Predecessor Period Acquisitions - Centex and Laser - Additional Information (Details) - USD ($) $ in Thousands	Dec. 23, 2021	Apr. 30, 2021
Business Acquisition [Line Items]
Business combination acquisition costs expensed	$ 19,010
Centex [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired		100.00%
Laser [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired		100.00%
Incodema Holdings Llc [Member] | Centex and Laser [Member]
Business Acquisition [Line Items]
Business combination acquisition costs expensed		$ 1,226
Payment of transaction fee to affiliate		$ 190

Fathom OpCo Predecessor Peri_29

Fathom OpCo Predecessor Period Acquisitions - Centex and Laser - Summary of Total Purchase Consideration Transferred (Details) $ in Thousands	Apr. 30, 2021USD ($)
Centex [Member]
Business Acquisition [Line Items]
Cash	$ 11,774
Fair value of total consideration transferred	11,774
Laser [Member]
Business Acquisition [Line Items]
Cash	6,946
Fair value of total consideration transferred	6,946
Centex and Laser [Member]
Business Acquisition [Line Items]
Cash	18,720
Fair value of total consideration transferred	$ 18,720

Fathom OpCo Predecessor Peri_30

Fathom OpCo Predecessor Period Acquisitions - Centex and Laser - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	[1]	Dec. 22, 2021	Apr. 30, 2021	Dec. 31, 2020	[1]	Jan. 01, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Intangible assets							$ 270,000
Goodwill	$ 1,189,464		$ 83,113		$ 63,215			$ 33,007
Centex [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Accounts receivable, net				$ 1,775
Inventory				524
Prepaid expenses				108
Fixed assets, net				1,787
Intangible assets				6,243
Other assets				1
Total assets acquired				10,438
Accounts payable				252
Paycheck Protection Program (PPP) loan				649
Accrued expenses				271
Other current liabilities				23
Other noncurrent liabilities				1,234
Total liabilities assumed				2,429
Total identifiable net assets				8,009
Goodwill				3,765
Laser [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash				68
Accounts receivable, net				900
Inventory				622
Prepaid expenses				1
Fixed assets, net				760
Intangible assets				3,557
Other assets				2
Total assets acquired				5,910
Accounts payable				568
Paycheck Protection Program (PPP) loan
Accrued expenses				27
Other current liabilities				44
Other noncurrent liabilities				703
Total liabilities assumed				1,342
Total identifiable net assets				4,568
Goodwill				$ 2,378
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_31

Fathom OpCo Predecessor Period Acquisitions - Centex and Laser - Summary of Intangible Assets Acquired in Acquisition (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Dec. 31, 2021	Jan. 01, 2020
Finite Lived Intangible Assets [Line Items]
Intangible assets			$ 270,000
Acquisition Date Fair Value	$ 3,557
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		15 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		19 years
Centex [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets	6,243
Acquisition Date Fair Value	6,243
Centex [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 510
Estimated Life (Years)	5 years
Centex [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 5,733
Estimated Life (Years)	17 years
Laser [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets	$ 3,557
Laser [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 290
Estimated Life (Years)	5 years
Laser [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 3,267
Estimated Life (Years)	17 years

Fathom OpCo Predecessor Peri_32

Fathom OpCo Predecessor Period Acquisitions - Centex and Laser - Summary of Revenue and Net (Loss) Income Since Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Business Acquisition [Line Items]
Revenue	$ 4,840		$ 147,356		$ 61,289
Net income (loss)	$ 34,438	[1]	(16,474)	[2]	$ (7,963)	[2]
Centex and Laser [Member]
Business Acquisition [Line Items]
Revenue			9,642
Net (loss)			$ (98)
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_33

Fathom OpCo Predecessor Period Acquisitions - Micropulse West - Additional Information (Details) - USD ($) $ in Thousands	Dec. 23, 2021	Apr. 30, 2021
Business Acquisition [Line Items]
Business combination acquisition costs expensed	$ 19,010
Micropulse West [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interests acquired		100.00%
Payment of transaction fee to affiliate		$ 130
Micropulse West [Member] | Other Expense [Member]
Business Acquisition [Line Items]
Business combination acquisition costs expensed		$ 869

Fathom OpCo Predecessor Peri_34

Fathom OpCo Predecessor Period Acquisitions - Micropulse West - Summary of Total Purchase Consideration Transferred (Details) - Micropulse West [Member] $ in Thousands	Apr. 30, 2021USD ($)
Business Acquisition [Line Items]
Cash	$ 12,452
Contingent consideration	1,295
Fair value of total consideration transferred	$ 13,747

Fathom OpCo Predecessor Peri_35

Fathom OpCo Predecessor Period Acquisitions - Micropulse West - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	[1]	Dec. 22, 2021	Apr. 30, 2021	Dec. 31, 2020	[1]	Jan. 01, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed
Intangible assets							$ 270,000
Goodwill	$ 1,189,464		$ 83,113		$ 63,215			$ 33,007
Micropulse West [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash				$ 70
Accounts receivable, net				866
Inventory				333
Other current assets				10
Fixed assets, net				2,490
Intangible assets				7,000
Total assets acquired				10,769
Accounts payable				139
Accrued expenses				13
Other current liabilities				99
Total liabilities assumed				251
Total identifiable net assets				10,518
Goodwill				$ 3,229
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_36

Fathom OpCo Predecessor Period Acquisitions - Micropulse West - Summary of Intangible Assets Acquired in Acquisition (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Dec. 31, 2021	Jan. 01, 2020
Finite Lived Intangible Assets [Line Items]
Intangible assets			$ 270,000
Acquisition Date Fair Value	$ 3,557
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		15 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		19 years
Micropulse West [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets	7,000
Acquisition Date Fair Value	7,000
Micropulse West [Member] | Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 600
Estimated Life (Years)	5 years
Micropulse West [Member] | Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition Date Fair Value	$ 6,400
Estimated Life (Years)	17 years

Fathom OpCo Predecessor Peri_37

Fathom OpCo Predecessor Period Acquisitions - Micropulse West - Summary of Revenue and Net (Loss) Income Since Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Business Acquisition [Line Items]
Revenue	$ 4,840		$ 147,356		$ 61,289
Net income (loss)	$ 34,438	[1]	(16,474)	[2]	$ (7,963)	[2]
Micropulse West [Member]
Business Acquisition [Line Items]
Revenue			4,614
Net (loss)			$ (115)
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Predecessor Peri_38

Fathom OpCo Predecessor Period Acquisitions - Other Acquisitions - Additional Information (Details) - USD ($) $ in Thousands	Dec. 18, 2020	Aug. 18, 2020
GPI Prototype & Manufacturing Services, LLC [Member]
Business Acquisition [Line Items]
Fair value of total consideration transferred		$ 2,441
Mark Two Engineering, LLC [Member]
Business Acquisition [Line Items]
Fair value of total consideration transferred	$ 6,639
Business acquisition, percentage of interests acquired	100.00%

Revenue - Schedule of Revenue b

Revenue - Schedule of Revenue by Product Line (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 4,840	$ 147,356	$ 61,289
Additive Manufacturing
Disaggregation Of Revenue [Line Items]
Total revenue	567	17,270	19,032
Injection Molding
Disaggregation Of Revenue [Line Items]
Total revenue	919	27,968	17,093
CNC Machining
Disaggregation Of Revenue [Line Items]
Total revenue	1,372	41,775	9,173
Precision Sheet Metal
Disaggregation Of Revenue [Line Items]
Total revenue	1,700	51,751	9,811
Ancillary Product Lines
Disaggregation Of Revenue [Line Items]
Total revenue	$ 282	$ 8,592	$ 6,180

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Other Current Liabilities
Disaggregation Of Revenue [Line Items]
Deferred revenue	$ 1,147	$ 1,210

Inventory - Summary of Inventor

Inventory - Summary of Inventory (Details) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Inventory Net [Abstract]
Finished goods		$ 3,506	$ 1,819
Raw materials		4,967	2,277
Work in process		5,368	2,359
Tooling		605	338
Inventory, gross		14,446	6,793
Allowance for obsolescence		(1,281)	(468)
Total	[1]	$ 13,165	$ 6,325
[1]	See accompanying notes to the consolidated financial statements.

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 44,659	$ 29,440
Accumulated depreciation and amortization		(132)	(3,054)
Total	[1]	44,527	26,386
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 33,182	25,214
Estimated Useful Life		5 years
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 180	812
Estimated Useful Life		2 years
Computer Hardware
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 499
Estimated Useful Life		2 years
Computer Software
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 305
Estimated Useful Life		2 years
Property and Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 7,180	2,838
Property and Leasehold Improvements | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life		3 years
Property and Leasehold Improvements | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life		23 years
Construction in Progress
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 2,859	576
Auto / Transportation Equipment
Property Plant And Equipment [Line Items]
Property and Equipment, Gross		$ 454
Estimated Useful Life		3 years
[1]	See accompanying notes to the consolidated financial statements.

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Depreciation and amortization expense	[1]	$ 416	$ 10,357	$ 4,672
Operating Expense [Member]
Property Plant And Equipment [Line Items]
Depreciation and amortization expense		60	700	445
Cost of Revenue [Member]
Property Plant And Equipment [Line Items]
Depreciation and amortization expense		$ 72	$ 4,873	$ 2,567
[1]	See accompanying notes to the consolidated financial statements.

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	$ 83,113		$ 63,215	[1]	$ 33,007
Goodwill acquired	1,189,464		19,898		30,208
Goodwill	$ 1,189,464	[1]	$ 83,113		$ 63,215	[1]
[1]	See accompanying notes to the consolidated financial statements.

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets Other Than Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 270,000	$ 90,700
Finite-Lived Intangible Assets, Accumulated Amortization	378	7,234
Finite-Lived Intangible Assets, Net	269,622	83,466
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	70,000	12,200
Finite-Lived Intangible Assets, Accumulated Amortization	98	919
Finite-Lived Intangible Assets, Net	$ 69,902	$ 11,281
Useful Life (in years)	15 years
Trade Name [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		5 years
Trade Name [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		15 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 180,000	$ 67,600
Finite-Lived Intangible Assets, Accumulated Amortization	252	4,448
Finite-Lived Intangible Assets, Net	$ 179,748	$ 63,152
Useful Life (in years)	19 years
Customer Relationships [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		5 years
Customer Relationships [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Useful Life (in years)		17 years
Developed Software [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 4,300	$ 6,400
Finite-Lived Intangible Assets, Accumulated Amortization	6	720
Finite-Lived Intangible Assets, Net	$ 4,294	$ 5,680
Useful Life (in years)	5 years	5 years
Developed Technology [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 15,700	$ 4,500
Finite-Lived Intangible Assets, Accumulated Amortization	22	1,147
Finite-Lived Intangible Assets, Net	$ 15,678	$ 3,353
Useful Life (in years)	5 years	5 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense	$ 378	$ 10,535	$ 4,227
Intangible assets other than goodwill with indefinite useful lives	$ 0

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Schedule of Estimated Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
2022	$ 17,280
2023	17,280
2024	17,280
2025	17,280
2026	17,280
Thereafter	183,222
Total	$ 269,622	$ 83,466

Warrant Liability - Additional

Warrant Liability - Additional Information (Details) - $ / shares	Feb. 09, 2021	Dec. 31, 2021
Public Warrants
Class Of Warrant Or Right [Line Items]
Class of warrants or rights outstanding (in shares)		8,625,000
Stock price trigger for redemption of public warrants (in dollars per share)		$ 18
Threshold trading days for redemption of public warrants		20 days
Threshold consecutive trading days for redemption of public warrants		30 days
Public Warrants | Redemption Of Warrants When Price Per Share Of Class Common Stock Equals Or Exceeds1800
Class Of Warrant Or Right [Line Items]
Minimum threshold written notice period for redemption of public warrants	30 days
Stock price trigger for redemption of public warrants (in dollars per share)	$ 18
Redemption price per public warrant (in dollars per share)	$ 0.01
Threshold trading days for redemption of public warrants	20 days
Threshold consecutive trading days for redemption of public warrants	30 days
Notice period	3 days
Private Placement Warrants
Class Of Warrant Or Right [Line Items]
Class of warrants or rights outstanding (in shares)		9,900,000
Minimum threshold written notice period for redemption of public warrants		30 days

Warrant Liability - Summary of

Warrant Liability - Summary of Number of Outstanding Warrants and Fair Value (Details) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Class Of Warrant Or Right [Line Items]
Fair value of warrants	[1]	$ 33,900	$ 0
Public Warrants
Class Of Warrant Or Right [Line Items]
Number of outstanding warrants		8,625,000
Fair value of warrants		$ 7,600
Private Placement Warrants
Class Of Warrant Or Right [Line Items]
Number of outstanding warrants		9,900,000
Fair value of warrants		$ 26,300
[1]	See accompanying notes to the consolidated financial statements.

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 23, 2021	Apr. 30, 2021	Dec. 16, 2020	Jul. 27, 2020	Dec. 31, 2021	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Amortization of debt issuance costs	$ 16							$ 3,126	$ 205
Long term debt date of maturity	Jul. 27, 2026					Jul. 27, 2026	Jul. 27, 2026
Interest and debt expense	$ 251							$ 13,063	3,635
Financing agreement maturity period						10 months
Financing payments						$ 3,001
Financing fee						$ 35
Financing annual rate						2.57%
New Credit Agreement [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long term debt		$ 152,000
Debt issuance costs gross		$ 1,828
Long term debt date of maturity		Dec. 31, 2026
Increase decrease in term loan facility and revolving credit facility		$ 100,000
New Credit Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument face value		125,000
Revolving Credit Facility [Member] | New Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity		50,000
Borrowings from credit agreement	$ 27,000					$ 27,000	$ 27,000
Two Thousand And Twenty One Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument face value			$ 172,000
Repayment of loan			$ 20,000
Paycheck Protection Programme Loan [Member]
Debt Instrument [Line Items]
Proceeds from issuance of long term debt									1,624
Forgiveness of debt							$ 1,624
Two Thousand And Eighteen Credit Facility [Member] | Second and Third Amendment Agreement To The Credit Facility [Member] | Delayed Draw Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument unused borrowing capacity									510
Two Thousand And Eighteen Credit Facility [Member] | Revolving Credit Facility [Member] | Second and Third Amendment Agreement To The Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility capacity available for specific purposes other than trade purchases									$ 3,100
Two Thousand And Twenty Credit Facility [Member] | Secured Subordinated Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument face value				$ 40,500	$ 34,500
Two Thousand And Twenty Credit Facility [Member] | Secured Subordinated Credit Facility [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument face value					19,500
Proceeds from issuance of long term debt					19,500
Debt issuance costs gross					$ 520
Debt instrument date of first required payment					Sep. 30, 2020
Debt instrument periodic payment principal					$ 50
Debt instrument frequency of periodic payment					quarterly
Two Thousand And Twenty Credit Facility [Member] | Secured Subordinated Credit Facility [Member] | Delayed Draw Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument face value					$ 15,000
Debt instrument date of first required payment					Mar. 31, 2021
Debt instrument periodic payment principal					$ 100
Long term debt variable interest rate percentage									7.738%
Debt instrument unused borrowing capacity commitement fee percentage	1.00%			0.50%		1.00%	1.00%
Amortization of debt issuance costs				$ 32
Debt issuance costs capitalized				32
Debt instrument frequency of periodic payment					quarterly
Two Thousand And Twenty Credit Facility [Member] | Secured Subordinated Credit Facility [Member] | Delayed Draw Term Loan [Member] | For The First Six Months [Member]
Debt Instrument [Line Items]
Debt issuance costs gross				692
Amortization of debt issuance costs				660
Debt issuance costs capitalized				$ 660
Letter of Credit [Member] | Revolving Credit Facility [Member] | New Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity		$ 5,000

Debt - Schedule of Long-term De

Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2021
Debt Instrument [Line Items]
Total principal long-term debt		$ 92,591
Debt issuance costs		(1,867)	$ (1,812)
Total debt		93,339	150,188
Less: current portion of long-term debt	[1]	2,853	29,697
Long-term debt, net of current portion	[1]	$ 90,486	120,491
Two Thousand And Eighteen Term Loan As Amended [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		7.75%
Principal debt		$ 29,700	0
Two Thousand And Eighteen Delay Draw Down Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate		7.75%
Principal debt		$ 2,990	0
Two Thousand And Twenty Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate Terms		3-month LIBOR + 7.50%
Principal debt		$ 19,401	0
Two Thousand And Twenty Delay Draw Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate Terms		3-month LIBOR + 7.50%
Principal debt		$ 40,500	$ 0
New Credit Agreement Revolver [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate			3.60%
Principal debt		0	$ 27,000
New Credit Agreement Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate			3.72%
Principal debt		0	$ 125,000
Paycheck Protection Programme and Other Loans [Member]
Debt Instrument [Line Items]
Principal debt		$ 2,615	$ 0
[1]	See accompanying notes to the consolidated financial statements.

Debt - Schedule of Long-term _2

Debt - Schedule of Long-term Debt Instruments (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2020
Two Thousand And Twenty Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	7.50%
Two Thousand And Twenty Delay Draw Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	7.50%

Debt - Schedule of Balances of

Debt - Schedule of Balances of Term Loan (Details) $ in Thousands	Dec. 31, 2021USD ($)
Debt Disclosure [Abstract]
2022	$ 3,096
2023	5,982
2024	8,453
2025	7,836
2026	99,633
Thereafter	0
Total	$ 125,000

Other Income and Expense, Net -

Other Income and Expense, Net - Schedule of Other Income and Expense, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Other Income And Expenses [Abstract]
Acquisition expenses	$ 0	$ 4,045	$ 1,254
Transaction expense	0	12,515	0
Loss on debt extinguishment	0	2,031	0
Loan prepayment fees	0	1,463
Change in fair value of contingent consideration	0	0	1,055
Change in fair value of TRA	300	0	0
Loss on sale of assets		307
Other	8	646	1,515
Other expense	308	21,007	3,824
Gain on sale of assets	0	0	214
Gain on PPP forgiveness		(1,624)	0
Change in fair value of Sponsor Earnout Shares	(3,400)	0
Change in fair value of contingent consideration	(23,860)	(3,550)	0
Change in fair value of Warrants	(8,200)	0	0
Other	0	0	(371)
Other income	(35,460)	(5,174)	(585)
Other (income) and expense, net	$ (35,152)	$ 15,833	$ 3,239

Share Based Compensation - Addi

Share Based Compensation - Additional Information (Details) - USD ($)	Dec. 31, 2021	Dec. 23, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of proceeds attributable to common units						10.00%
Share-based compensation expense			$ 0		$ 2,649,000	$ 34,000
Plan modification description				the performance-based awards were subject to modification accounting under ASC 718, the performance-based awards were considered an improbable-to-improbable modification and thus the grant date fair value of the performance based-awards was reset as of the modification date which was July 15, 2021. The time-based awards were also considered subject to modification accounting, however the time-based awards were considered a probable-to-probable modification whereby the original grant date fair value of the award is retained for accounting purposes. For both the modified time-based and performance based awards, the fair value of the original award and the fair value of the modified award were deemed to have the same fair value as there were no changes to the inputs in the calculation of fair value of the awards. As such, there was no incremental fair value that needed to be recognized for either the time-based or performance-based awards as a result of modification accounting for such awards.
Performance-based awards issued ever vested					0	0
Unrecognized compensation cost			$ 554,000			$ 554,000
Cost expected to be recognized, weighted average period						2 years 9 months 18 days
Cash payments related to stock units/awards						$ 0
2021 Omnibus Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 139,000
Unrecognized compensation cost	$ 5,800,000			$ 5,800,000
Cost expected to be recognized, weighted average period	2 years 9 months 18 days
Fair value of shares vested	$ 0
Cash payments related to stock units/awards	$ 0
Share price (in dollars per share)		$ 10.53
Discount for lack of marketability		2.84%
Fair value per award granted	$ 8.21	$ 8.21
Risk-free interest rate, minimum		0.07%
Risk-free interest rate, maximum		0.97%
Expected volatility, minimum		75.40%
Expected volatility, maximum		107.80%
Expected dividend yield		0.00%
Expected term		2 years 4 months 24 days
Forfeited, awards	0
2021 Omnibus Plan [Member] | ASC 718 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per award granted		$ 7.69
Time-based Awards [Member] | 2021 Omnibus Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per award granted		10
Time-based Awards [Member] | 2021 Omnibus Plan [Member] | ASC 718 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per award granted		$ 7.69
First Tranche [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%		25.00%
Vest increments when an investor cumulative sale threshold percentage				60.00%
Second Tranche [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%		75.00%
Vest increments when an investor cumulative sale threshold percentage				80.00%
Third Tranche [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				50.00%
Vest increments when an investor cumulative sale threshold percentage				95.00%

Share Based Compensation - Summ

Share Based Compensation - Summary of the activity in the plan (Details) - $ / shares	Dec. 31, 2021	Dec. 23, 2021	Dec. 22, 2021	Dec. 31, 2020
2021 Omnibus Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested ,Share	0	0
Granted , Shares	6,472,617
Vested , Shares	0
Forfeited , Shares	0
Nonvested ,Shares	6,472,617		0
Nonvested	$ 0	$ 0
Granted	8.21	$ 8.21
Vested	0
Forfeited	0
Nonvested	$ 8.21		$ 0
Twenty Twenty Activity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested ,Share			9,043	4,000
Granted , Shares				5,356
Vested , Shares				313
Forfeited , Shares				0
Nonvested ,Shares				9,043
Nonvested			$ 420.02	$ 515.09
Granted				358.15
Vested				570.20
Forfeited				0
Nonvested				$ 420.02
Twenty Twenty One Activity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested ,Share	11,568	11,568	9,043
Granted , Shares			14,346
Vested , Shares			1,115
Forfeited , Shares			10,706
Nonvested ,Shares			11,568	9,043
Nonvested	$ 1,217.42	$ 1,217.42	$ 420.02
Granted			1,529.06
Vested			1,930.42
Forfeited			888.81
Nonvested			$ 1,217.42	$ 420.02

Earnings Per Share and Earnin_3

Earnings Per Share and Earnings per Unit - Scheduled Basic Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Numerator
Net Income Attributable to Fathom Digital Manufacturing		$ 34,438	[1]	$ (16,474)	[2]	$ (7,963)	[2]
Denominator
Weighted average shares of Class A common stock outstanding-basic	[1]	50,785,656
Basic Earnings Per Share	[1]	$ 0.68
Class A Common Units [Member]
Numerator
Net Income Attributable to Fathom Digital Manufacturing		$ 33,470		(11,690)		(5,380)
Less: Net loss attributable to non-controlling interests		(968)
Net (loss) attributable to common unitholders		$ 34,438		$ (18,272)		$ (9,463)
Denominator
Weighted average shares of Class A common stock outstanding-basic		50,785,656		5,480,611		3,531,681
Basic Earnings Per Share		$ 0.68
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.

Earnings Per Share and Earnin_4

Earnings Per Share and Earnings Per Unit - Scheduled Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Numerator
Net Income Attributable to Fathom Digital Manufacturing		$ 34,438	[1]	$ (16,474)	[2]	$ (7,963)	[2]
Denominator
Weighted average shares of Class A common stock outstanding-basic	[1]	50,785,656
Effect of Dilutive Securities
Weighted average shares of Class A common stock outstanding-diluted	[1]	135,839,973
Diluted Earnings Per Share	[1]	$ 0.25
Class A Common Units [Member]
Numerator
Net Income Attributable to Fathom Digital Manufacturing		$ 33,470		$ (11,690)		$ (5,380)
Denominator
Weighted average shares of Class A common stock outstanding-basic		50,785,656		5,480,611		3,531,681
Effect of Dilutive Securities
Assumed exchange for shares of Class A common stock		85,054,317
Weighted average shares of Class A common stock outstanding-diluted		135,839,973
Diluted Earnings Per Share		$ 0.25
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.

Earnings Per Share and Earnin_5

Earnings Per Share and Earnings per Unit - Summary of Earnings Per Unit (Details) - USD ($) $ / shares in Units, $ in Thousands		Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Basic Earnings Per Unit: Numerator
Net (loss)		$ 34,438	[1]	$ (16,474)	[2]	$ (7,963)	[2]
Weighted average shares of Class A common stock outstanding-basic	[1]	50,785,656
Basic and Diluted Earnings Per Unit	[1],[3]			$ (3.33)		$ (2.68)
Class A Common Units [Member]
Basic Earnings Per Unit: Numerator
Net (loss)		$ 33,470		$ (11,690)		$ (5,380)
Less: annual dividends on redeemable preferred units				(6,582)		(4,083)
Net (loss) attributable to common unitholders		$ 34,438		$ (18,272)		$ (9,463)
Weighted average shares of Class A common stock outstanding-basic		50,785,656		5,480,611		3,531,681
Basic and Diluted Earnings Per Unit				$ (3.33)		$ (2.68)
Class B Common Stock [Member]
Basic Earnings Per Unit: Numerator
Net (loss)				$ (4,784)		$ (2,583)
Less: annual dividends on redeemable preferred units				(2,694)		(1,961)
Net (loss) attributable to common unitholders				$ (7,478)		$ (4,544)
Weighted average shares of Class A common stock outstanding-basic				2,242,981		1,696,135
Basic and Diluted Earnings Per Unit				$ (3.33)		$ (2.68)
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.
[3]	Basic and diluted net loss per unit amounts are the same for both Class A common units and Class B common units. See Note 13.

Shareholders' Equity, Noncont_3

Shareholders' Equity, Noncontrolling interest, and Members' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 23, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock, shares authorized	500,000,000
Preferred stock, shares authorized	10,000,000
Preferred stock, par value	$ 0.0001
Preferred stock, shares outstanding	0
Fathom OpCo [Member]
Class Of Stock [Line Items]
Noncontrolling interest at fair value		$ 842,850
Noncontrolling interest Company owns	37.60%
Noncontrolling interest, ownership percentage	62.40%
Class A Common Units [Member]
Class Of Stock [Line Items]
Common units voting rights	one vote
Common stock, shares authorized			5,480,611
Common stock, par value			$ 100
Common stock, shares outstanding			5,480,611
Class B Common Units [Member]
Class Of Stock [Line Items]
Common units voting rights	not entitled to vote
Common stock, shares authorized			2,242,981
Common stock, par value			$ 100
Common stock, shares outstanding			2,242,981
Class A Common Stock [Member]
Class Of Stock [Line Items]
Common units voting rights	one-for-one basis for shares of Class A common stock
Common stock, shares authorized	300,000,000
Common stock, par value	$ 0.0001
Common stock, shares outstanding	50,785,656
Common Stock, Voting Rights	one vote per share
Class B Common Stock [Member]
Class Of Stock [Line Items]
Common stock, shares authorized	180,000,000
Common stock, par value	$ 0.0001
Common stock, shares outstanding	84,294,971
Common Stock, Voting Rights	one vote per share
Class C Common Stock [Member]
Class Of Stock [Line Items]
Common stock, shares authorized	10,000,000
Common stock, par value	$ 0.0001
Common stock, shares outstanding	0

Shareholders' Equity, Non-contr

Shareholders' Equity, Non-controlling interest, and Members' Equity - Schedule Of Calculation Of Comprehensive Loss Attributable To Non-controlling Interest Holders (Details) - USD ($)		Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Noncontrolling Interest [Line Items]
Fathom OpCo comprehensive loss	[1]	$ 34,438,000	$ (16,361,000)	$ (8,031,000)
Comprehensive loss attributable to noncontrolling interest	[1]	(968,000)
Fathom OpCo [Member]
Noncontrolling Interest [Line Items]
Fathom OpCo comprehensive loss		$ (1,551,000)
Noncontrolling interest percentage		62.40%
Comprehensive loss attributable to noncontrolling interest		$ (968,000)
[1]	See accompanying notes to the consolidated financial statements.

Shareholders' Equity, Noncont_4

Shareholders' Equity, Noncontrolling interest, and Members' Equity - Schedule Of Members Equity (Details)	Dec. 31, 2020shares
Class A Common Units [Member]
Members Equity [Line Items]
Common units, Outstanding	5,480,611
Class B Common Units [Member]
Members Equity [Line Items]
Common units, Outstanding	2,242,981

Operating Leases (Additional In

Operating Leases (Additional Information) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 22, 2021	Dec. 22, 2020
Lessee, Lease, Description [Line Items]
Rental expense	$ 53	$ 2,226	$ 1,536
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lease terms	2 years
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lease terms	7 years

Operating Leases - Schedule of

Operating Leases - Schedule of Future Minimum Rental Payments for Operating Leases (Details) $ in Thousands	Dec. 31, 2021USD ($)
Leases, Operating [Abstract]
2022	$ 3,212
2023	3,027
2024	1,959
2025	1,253
2026	443
Thereafter	328
Total Future Lease Payments	$ 10,222

Fathom OpCo Class A Contingen_3

Fathom OpCo Class A Contingently Redeemable Preferred Units - Schedule of Class A Contingently Redeemable Preferred Units Issued and Outstanding (Details) - USD ($) $ / shares in Units, $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Temporary Equity [Line Items]
Temporary Equity, Carrying value	[1]	$ 0	$ 54,105
Class A Preferred Units [Member]
Temporary Equity [Line Items]
Temporary Equity, Shares Authorized			1,167,418
Temporary Equity, Shares Issued			1,167,418
Temporary Equity, Shares Outstanding			1,167,418
Temporary Equity, Original Issuance Price			$ 46.35
Temporary Equity, Carrying value			$ 54,105
Temporary Equity, Accumulated Unpaid Dividends			9,253
Temporary Equity, Amount contingently redeemable			$ 63,358
[1]	See accompanying notes to the consolidated financial statements.

Fathom OpCo Class A Contingen_4

Fathom OpCo Class A Contingently Redeemable Preferred Units (Additional Information) (Details) - USD ($)	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Temporary Equity [Line Items]
Payments of dividends	$ 0	$ 0	$ 0
Class A Preferred Units [Member]
Temporary Equity [Line Items]
Temporary equity, par value (in dollars per share)	$ 100
Temporary equity accumulated preferred return percentage	8.00%
Dividends		0	0
Payments of dividends		$ 0	$ 0

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Management Services Agreement [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses	$ 0	$ 1,723	$ 722
Affiliate [Member]
Related Party Transaction [Line Items]
Related party transaction purchases from related party	$ 700	$ 9,165	$ 6,438

Fair Value Measurement - Schedu

Fair Value Measurement - Schedule of Fair Value Measurement of Assets and Liabilities Based on Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	$ 115,778	$ 11,439
Level 1 | Warrant Liability – public Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	7,600
Level 3 | Tax Receivable Agreement
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	4,600
Level 3 | Legacy Fathom OpCo acquisitions contingent consideration
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	3,598	$ 11,439
Level 3 | Sponsor Earnout Shares Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	9,380
Level 3 | Fathom Earnout Shares Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	64,300
Level 3 | Warrant liability – Private Placement Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	$ 26,300

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Details) - 12 months ended Dec. 31, 2021 $ / shares in Units, $ in Thousands	USD ($)$ / shares	Total	yr
Public Warrants [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value measurements		11.50	5
Stock price trigger for redemption of public warrants (in dollars per share) | $ / shares	$ 18
Threshold trading days for redemption of public warrants	20 days
Threshold consecutive trading days for redemption of public warrants	30 days
Tax Receivable Agreement [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Corporate tax rate	26.90%
Non-controlling interest percentage	37.60%
Initial amortization deductions | $	$ 52,400
Taxable income forecast | $	$ 126,000
Tax Receivable Agreement [Member] | Class A Common Stock [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Business combination contingent consideration liability measurement input		84.6
Stock price, per share | $ / shares	$ 7.92
Sale of stock price percentage	25.00%
Earnout Shares [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Expected term	5 years
Risk-free interest rate	1.25%
Strike Price [Member] | Private Placement Warrants [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value measurements		11.50
Expected Term [Member] | Private Placement Warrants [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value measurements | yr			5
Volatility [Member] | Private Placement Warrants [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value measurements		25
Operating Asset Volatility [Member] | Earnout Shares [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Volatility	87.60%
Equity Volatility [Member] | Earnout Shares [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Volatility	91.70%
Minimum [Member] | Tax Receivable Agreement [Member] | Class A Common Stock [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cost of debt percentage	2.40%
Maximum [Member] | Tax Receivable Agreement [Member] | Class A Common Stock [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cost of debt percentage	8.50%

Fair Value Measurement - Sche_2

Fair Value Measurement - Schedule of Reconciliation Liabilities Measured at Fair Value on a Recurring Basis Using Significant on Observable Inputs (Detail) - Level 3 - Contingent Consideration - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value, Beginning Balance	$ 141,438
Included in earnings	(33,260)	$ 1,055
Issuances		11,737
Payments		(1,353)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value, Ending Balance	$ 108,178	$ 11,439

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Income tax expense or benefits, uncertain tax positions	$ 0	$ 0	$ 0
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	5,600,000
State
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 5,600,000

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Current Expense
State	$ 0		$ 52		$ 0
Federal	0		0		0
Current Federal, State and Local, Tax Expense (Benefit), Total	0		52		0
Deferred tax benefit
State	(1)		(297)		0
Federal	(2)		(2,963)		0
Deferred Federal, State and Local, Tax Expense (Benefit), Total	(3)		(3,260)		0
Total	$ (3)	[1]	$ (3,208)	[1]	$ 0
[1]	See accompanying notes to the consolidated financial statements.

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Expected Statutory Federal Tax and the Total Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 22, 2021		Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory rate (21%)	$ 7,028		$ (4,133)		$ (1,672)
State income taxes, net of federal benefit	(38)		(245)		0
Pre-closing income held in flow-through entities	0		4,133		1,672
Change in tax status of corporate subsidiaries	0		(2,963)		0
Non-controlling interest in Fathom Holdco, LLC	222		0		0
Remeasurement of Fathom and Sponsor earnout shares	(5,724)
Remeasurement of TRA and warrant liability	(1,662)		0		0
Valuation allowance	171
Total	$ (3)	[1]	$ (3,208)	[1]	$ 0
[1]	See accompanying notes to the consolidated financial statements.

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of the Expected Statutory Federal Tax and the Total Income Tax Expense (Benefit) (Parenthetical) (Details)	Dec. 31, 2021	Dec. 22, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory rate percentage	21.00%	21.00%	21.00%

Income Taxes - Summary of Tax E

Income Taxes - Summary of Tax Effect of Temporary Differences to Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Net operating losses	$ 1,494	$ 0
Transaction costs	861
Interest expense carryforwards	762
Valuation allowance	(3,117)	0
Total deferred tax assets	0	0
Deferred tax liabilities
Investment in Fathom Holdco, LLC	(17,570)
Total deferred tax liabilities	(17,570)
Total net deferred tax liabilities	$ (17,570)

Variable Interest Entity - Summ

Variable Interest Entity - Summary of Total Assets, Liabilities, and Equity of the Company's Consolidated VEI (Details) - USD ($) $ in Thousands		Dec. 31, 2021		Dec. 22, 2021	[2]	Dec. 31, 2020		Dec. 31, 2019	[2]
Variable Interest Entity [Line Items]
Total assets	[1]	$ 1,566,374				$ 206,779
Total liabilities	[1]	305,615				116,655
Total equity		418,777	[1]	$ 22,307		$ 36,019	[2]	$ 22,899
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Total assets		1,566,106
Total liabilities		193,437
Total equity		$ 1,372,669
[1]	See accompanying notes to the consolidated financial statements.
[2]	See accompanying notes to the consolidated financial statements.