Bowman Consulting (BWMN) S-1 1 Feb 22 IPO registration Financial data

Cover Page

Cover Page	9 Months Ended
	Sep. 30, 2021
Cover [Abstract]
Document Type	S-1
Amendment Flag	false
Entity Registrant Name	BOWMAN CONSULTING GROUP LTD.
Entity Central Index Key	0001847590
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and equivalents	$ 38,745	$ 386	$ 509
Accounts Receivable, net	34,964	24,183	28,555
Contract assets	8,668	7,080	10,108
Notes receivable, current			904
Notes receivable—officers, employees, affiliates, current portion	1,120	1,182	525
Prepaid and other current assets	3,858	2,271	2,287
Total current assets	87,355	35,102	42,888
Non-Current Assets
Property and equipment, net	17,864	15,357	4,770
Goodwill	13,484	9,179	9,179
Notes receivable	903	903
Notes receivable—officers, employees, affiliates, less current portion	1,273	1,297	8,470
Other intangible assets, net	2,789	1,131	691
Other assets	687	669	800
Total Assets	124,355	63,638	66,798
Current Liabilities
Bank line of credit	0	3,481	8,348
Accounts payable and accrued liabilities, current portion	18,634	12,203	14,170
Contract liabilities	2,558	1,943	7,888
Notes payable, current portion	2,222	1,592	1,744
Deferred rent, current portion	674	619	310
Capital lease obligation, current portion	4,625	3,495	143
Total current liabilities	28,713	23,333	32,603
Non-Current Liabilities
Other non-current obligations	1,243	1,244
Notes payable, less current portion	4,377	2,829	1,916
Deferred rent, less current portion	4,217	4,278	4,057
Capital lease obligation, less current portion	8,855	7,503	574
Deferred tax liability, net	5,133	6,472	6,046
Common shares subject to repurchase	7	842	8,267
Total liabilities	52,545	46,501	53,463
Shareholders' Equity
Preferred Stock, $0.01 par value; 5,000,000 shares authorized, no shares issued and outstanding
Common stock, $0.01 par value; 30,000,000 shares authorized; 13,367,535 shares issued and 11,179,120 outstanding, and 7,840,244 shares issued and 5,744,594 outstanding, respectively	134	2
Additional paid-in-capital	113,531	58,866
Treasury Stock, at cost; 2,188,415 and 2,095,650, respectively	(17,215)	(16,022)	(5,925)
Stock subscription notes receivable	(439)	(609)
Accumulated deficit	(24,201)	(25,100)	(17,358)
Total shareholders' equity	71,810	17,137	(23,283)
TOTAL LIABILITIES AND EQUITY	$ 124,355	$ 63,638	66,798
Redeemable Common Stock [Member]
Non-Current Liabilities
Redeemable common stock			$ 36,618

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	13,367,535	7,840,244
Common stock, shares outstanding	11,179,120	5,744,594
Treasury stock, shares	2,188,415	2,095,650

Condensed Consolidated Income S

Condensed Consolidated Income Statements - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Gross Contract Revenue	$ 39,715	$ 31,766	$ 108,041	$ 92,126	$ 122,020	$ 113,724
Contract costs: (exclusive of depreciation and amortization below)
Direct payroll costs	15,531	13,035	42,873	36,768	48,152	42,452
Sub-consultants and expenses	3,967	6,354	10,967	14,814	18,360	16,119
Total contract costs	19,498	19,389	53,840	51,582	66,512	58,571
Operating Expenses:
Selling, general and administrative	18,373	14,425	48,328	38,555	51,469	51,486
Depreciation and amortization	1,598	311	4,506	952	2,277	797
(Gain) loss on sale	(46)	(30)	(99)	(45)	(107)	(113)
Total operating expenses	19,925	14,706	52,735	39,462	53,639	52,170
Income (loss) from operations	292	(2,329)	1,466	1,082	1,869	2,983
Other (income) expense	314	(102)	706	(179)	(110)	419
Income (loss) before tax expense	(22)	(2,227)	760	1,261	1,979	2,564
Income tax (benefit) expense	(379)	(979)	(139)	467	989	1,038
Net income (loss)	357	(1,248)	899	794	$ 990	$ 1,526
Earnings allocated to non-vested shares	71		165	41
Net income (loss) attributable to common shareholders	$ 286	$ (1,248)	$ 734	$ 753
Earnings (loss) per share
Basic	$ 0.03	$ (0.22)	$ 0.10	$ 0.14	$ 0.17	$ 0.26
Diluted	$ 0.03	$ (0.22)	$ 0.10	$ 0.13	$ 0.17	$ 0.25
Weighted average shares outstanding:
Basic	8,920,505	5,567,523	7,003,462	5,569,177	5,399,356	5,770,170
Diluted	8,935,274	5,567,523	7,008,440	5,604,804	5,412,218	5,805,836

Condensed Consolidated Statemen

Condensed Consolidated Statements of Changes in Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Initial Public Offering	Common Stock	Common StockInitial Public Offering	Additional Paid-in Capital	Additional Paid-in CapitalInitial Public Offering	Treasury Stock	Stock Subscription Notes Receivable	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ (9,854)						$ (3,575)		$ (6,279)
Beginning balance, shares at Dec. 31, 2018			5,982,040
Issuance of new common shares, shares			117,056
Purchase of treasury stock	(2,350)						(2,350)
Purchase of treasury stock, shares			(342,525)
Issuance of common stock under stock bonus plan , shares			47,141
Common shares subject to repurchase liability	258								258
Fair value adjustment to redeemable common stock	(12,863)								(12,863)
Collections on stock subscription notes receivable	0
Net Income	1,526								1,526
Ending balance at Dec. 31, 2019	(23,283)						$ (5,925)		(17,358)
Ending balance, shares at Dec. 31, 2019			7,052,064				(1,248,352)
Ending balance, shares at Dec. 31, 2019			5,803,712
Issuance of new common shares, shares			69,827
Purchase of treasury stock	(9,587)						$ (9,587)
Purchase of treasury stock, shares			(2,950)				(807,297)
Issuance of common shares under stock compensation plan, shares			217,946
Common shares subject to repurchase liability	656								656
Fair value adjustment to redeemable common stock	(6,795)								(6,795)
Net Income	794								794
Ending balance at Sep. 30, 2020	(38,215)						$ (15,512)		(22,703)
Ending balance, shares at Sep. 30, 2020			7,336,887				(2,055,649)
Beginning balance at Dec. 31, 2019	(23,283)						$ (5,925)		(17,358)
Beginning balance, shares at Dec. 31, 2019			7,052,064				(1,248,352)
Issuance of new common shares	(533)							(533)
Issuance of new common shares, shares			133,458
Purchase of treasury stock	(10,097)						$ (10,097)
Purchase of treasury stock, shares			(850,249)
Issuance of common shares under stock compensation plan, shares			657,673
Collections on stock subscription notes receivable	234							234
Reclassification of common shares previously subject to repurchase liability	12,622				11,808				814
Conversion of redeemable common stock to permanent equity	37,204		$ 2		47,058			(310)	(9,546)
Net Income	990								990
Ending balance at Dec. 31, 2020	17,137		$ 2		58,866		$ (16,022)	(609)	(25,100)
Ending balance, shares at Dec. 31, 2020			7,840,244				(2,095,650)
Ending balance, shares at Dec. 31, 2020			5,744,594
Beginning balance at Jun. 30, 2020	(17,918)						$ (6,699)		(11,219)
Beginning balance, shares at Jun. 30, 2020			7,274,701				(1,361,160)
Issuance of new common shares, shares			49,560
Purchase of treasury stock	(8,813)						$ (8,813)
Purchase of treasury stock, shares							(694,489)
Issuance of common shares under stock compensation plan, shares			12,626
Common shares subject to repurchase liability	(1)								(1)
Fair value adjustment to redeemable common stock	(10,235)								(10,235)
Net Income	(1,248)								(1,248)
Ending balance at Sep. 30, 2020	(38,215)						$ (15,512)		(22,703)
Ending balance, shares at Sep. 30, 2020			7,336,887				(2,055,649)
Beginning balance at Dec. 31, 2020	17,137		$ 2		58,866		$ (16,022)	(609)	(25,100)
Beginning balance, shares at Dec. 31, 2020			7,840,244				(2,095,650)
Issuance of new common shares	1,275	$ 47,104	$ 1	$ 38	1,274	$ 47,066
Issuance of new common shares, shares			96,136	3,805,925
Purchase of treasury stock	(1,193)		$ 21		(21)		$ (1,193)
Purchase of treasury stock, shares							(92,765)
Issuance of common shares under stock compensation plan			$ 21		(21)
Issuance of common shares under stock compensation plan, shares			1,603,315
Issuance of new common shares under employee stock purchase plan	255		$ 0		255
Issuance of new common shares under employee stock purchase plan, shares			21,915
Stock based compensation	5,361				5,361
Collections on stock subscription notes receivable	170							170
Conversion of common shares subject to repurchase liability to permanent equity	878		$ 51		827
Capital reduction related to acquisition	(76)				(76)
Net Income	899								899
Ending balance at Sep. 30, 2021	71,810		$ 134		113,531		$ (17,215)	(439)	(24,201)
Ending balance, shares at Sep. 30, 2021			13,367,535				(2,188,415)
Beginning balance at Jun. 30, 2021	68,134		$ 133		110,218		$ (17,117)	(542)	(24,558)
Beginning balance, shares at Jun. 30, 2021			13,273,673				(2,181,428)
Issuance of new common shares	428				428
Issuance of new common shares, shares			32,143
Purchase of treasury stock	(98)						$ (98)
Purchase of treasury stock, shares							(6,987)
Issuance of common shares under stock compensation plan, shares			39,804
Issuance of new common shares under employee stock purchase plan	255		$ 1		254
Issuance of new common shares under employee stock purchase plan, shares			21,915
Stock based compensation	2,634				2,634
Collections on stock subscription notes receivable	103							103
Capital reduction related to acquisition	(3)				(3)
Net Income	357								357
Ending balance at Sep. 30, 2021	$ 71,810		$ 134		$ 113,531		$ (17,215)	$ (439)	$ (24,201)
Ending balance, shares at Sep. 30, 2021			13,367,535				(2,188,415)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities:
Net Income	$ 899	$ 794	$ 990	$ 1,526
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization—property, plant and equipment	4,283	762	2,036	514
Amortization of intangible assets	223	190	241	283
Gain on sale of assets	(99)	(45)	(110)	(117)
Bad debt	266	2,507	3,008	510
Stock based compensation	5,341	4,055	5,085	4,281
Interest on shares repurchased				14
Deferred taxes	(1,340)	297	326	431
Deferred rent	(6)	562	530	3,527
Changes in operating assets and liabilities
Accounts Receivable	(10,015)	369	1,506	(5,414)
Contract Assets	(961)	4,179	3,028	(1,680)
Prepaid expenses	(430)	702	623	(796)
Other Assets	(1,032)	(285)
Deposits and other assets			(28)	(145)
Accounts payable and accrued expenses	6,132	819	(520)	4,506
Contract Liabilities	(31)	(5,977)	(5,945)	778
Net cash provided by operating activities	3,230	8,929	10,770	8,218
Cash Flows from Investing Activities:
Purchases of property and equipment	(609)	(930)	(924)	(3,366)
Proceeds from sale of assets and disposal of leases			110	118
Proceeds from sale of assets	100	45
Amounts advanced under loans to shareholders	(473)	(878)	(1,207)	(1,303)
Payments received under loans to shareholders	88	195	228	821
Amounts advanced under notes receivable		(414)	(420)	(5,277)
Payments received under notes receivable		4	19	4,545
Acquisitions of businesses, net of cash acquired	(3,000)
Purchases of intangible assets			(416)	0
Collections under stock subscription notes receivable	170	144	196	191
Net cash used in investing activities	(3,724)	(1,834)	(2,414)	(4,271)
Cash Flows from Financing Activities:
Proceeds from initial public offering, net of underwriting discounts and commissions and other offering costs	47,104
Net repayments under revolving line of credit	(3,481)	(5,717)	(4,867)	(2,617)
Repayments under fixed line of credit	(540)	(306)	(485)	(195)
Borrowings under fixed line of credit		1,985	1,985
Repayment under notes payable	(735)	(1,496)	(1,800)	(776)
Payments on capital leases	(3,208)	(189)	(1,088)
Payment of contingent consideration from acquisitions	(2)	(104)	(106)	(128)
Payments for purchase of treasury stock	(582)	(1,261)
Payment of offering costs			(920)
Payments for purchase and retirement of common stock			(1,261)	(24)
Proceeds from issuance of common stock	297	45	63	130
Net cash provided by (used in) financing activities	38,853	(7,043)	(8,479)	(3,610)
Net increase in cash and cash equivalents	38,359	52	(123)	337
Cash and cash equivalents, beginning of period	386	509	509	172
Cash and cash equivalents, end of period	38,745	561	386	509
Supplemental disclosures of cash flow information:
Cash paid for interest	647	402	609	634
Cash paid for income taxes	1,040	228	543	362
Non-cash investing and financing activities
Property and equipment acquired under capital lease	(5,704)	(10,962)	(11,370)	(722)
(Issuance) Settlement of Redeemable Common Stock			36,927	13,069
Stock redemption for exercise of stock option	139
Issuance of common stock for a note receivable		533	533	7
Stock redemption for payment of shareholder loans		1,457	1,457	824
Stock redemption for payment on note receivable		6,130	6,130	0
Issuance of notes payable for purchase of intangible asset	$ (3,450)		165	0
Issuance of notes payable for redemption of stock		$ 604	$ 900	$ 1,267

Nature of Business and Basis of

Nature of Business and Basis of Presentation	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Nature Of Business And Basis Of Presentation [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Nature of Business Bowman Consulting Group Ltd. and its affiliates (“Bowman” or “we” or the “Company”) incorporated in the Commonwealth of Virginia on June 5, 1995, and reincorporated in the State of Delaware on November 13, 2020. Bowman is a professional services firm delivering innovative solutions to the marketplace of customers who own, develop and maintain the built environment. Within that arena, we provide planning, design, engineering, geomatics, survey, construction management, environmental consulting and land procurement services to markets that encompass the buildings in which people live, work and learn in. As well as the systems that provide water, electricity and other vital services, and the roads, bridges, and transportation systems used to get from place to place. We provide services to customers through fixed-price and time-and-material The Company’s workforce typically provides the full scope of engineering and other contract services. However, with respect to certain specialty services or other compliance requirements within a particular contract we may engage third-party sub-consultants. Initial Public Offering On May 11, 2021, we closed on our initial public offering (“IPO”), in which we issued and sold 3,690,000 shares of our common stock at $14.00 per share, resulting in net proceeds of $48.0 million after deducting underwriting discounts and commissions, but before expenses of the IPO. On June 4, 2021, the underwriters exercised their option to purchase an additional 115,925 shares of the Company’s common stock at the public offering price of $14.00 per share, resulting in additional gross proceeds of approximately $1.6 million. After giving effect to this partial exercise of the overallotment option, the total number of shares sold by Bowman in its initial public offering increased to 3,805,925 shares and gross proceeds increased to approximately $53.3 million. The exercise of the over-allotment option closed on June 8, 2021, at which time the Company received net proceeds of approximately $1.5 million after underwriting discounts and commissions. Deferred offering costs consist primarily of accounting, legal, and other fees related to our IPO. Prior to the IPO, all deferred offering costs were capitalized within prepaid and other current assets in the consolidated balance sheet. After the IPO, $2.3 million of deferred offering costs were reclassified into shareholder’s equity as a reduction of the IPO proceeds. We capitalized $0.9 million of deferred offering costs within prepaid and other current assets in the consolidated balance sheet as of December 31, 2020. Basis of Presentation The accompanying unaudited condensed consolidated financial statements and footnotes have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and applicable regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial information. In the opinion of management, the interim financial information includes all adjustments of a normal recurring nature necessary for a fair presentation of the results of operations, financial position, changes in shareholders’ equity and cash flows. The results of operations for the current period are not necessarily indicative of the results for the full year or the results for any future periods. The unaudited condensed consolidated financial statements should be read in conjunction with the audited combined financial statements and related footnotes included in our final prospectus dated May 6, 2021, and filed with the SEC pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.	1. Nature of Business and Basis of Presentation Nature of Business Bowman Consulting Group Ltd. and its affiliates (“Bowman” or “we” or the “Company”) incorporated in the Commonwealth of Virginia on June 5, 1995 and reincorporated in the State of Delaware on November 13, 2020. Bowman is a professional services firm delivering innovative solutions to the marketplace of customers who own, develop and maintain the built environment. Within that arena, we provide planning, design, engineering, geomatics, survey, construction management, environmental consulting and land procurement services to markets that encompass the buildings people live, work and learn in, the systems that provide water, electricity and other vital services, and the roads, bridges, and transportation systems used to get from place to place. We provide services to customers through fixed-price and time-and-material The Company’s workforce typically provides the full scope of engineering and other contract services. With respect to certain specialty services within a particular contract, however, we may engage the assistance of third-party sub-consultants. Basis of Presentation The accompanying combined financial statements include the accounts of the Company and its subsidiaries Bowman Environmental LC (BELC), Bowman International, Inc. (BII), Bowman Consulting Mexico, LLC (BCM), Bowman North Carolina Ltd. (BNCL). In addition, the financials include Bowman Consulting NC PC (NCPC), Omland Engineering, Land Survey and Landscape Architecture Associates, P.C. (BNY), and Bowman Consulting Group DC PC (DCPC), entities combined with the Company as of December 31, 2019 and 2020 based on common control. The Company eliminates all significant intercompany balances and transactions in its combined financial statements. Founded in Sonora, Mexico in 2017, BCM provides services to the Company exclusively. BELC, BII and BCM had minimal or no activity during the year ended December 31, 2019 and 2020. DCPC was incorporated in the District of Columbia in August 2014 September 2019 October 2002 Each state establishes licensing and organizational requirements for our services. Certain states allow only one individual and individually owned professional services corporations to hold licenses. In those states there sometimes exist grandfathering exemptions that allow corporations to hold licenses. In the event a state does not allow a corporation to hold a license, we have in the past formed professional services corporations owned by Mr. Bowman and other employees to facilitate our ability to work in such states, with two such states being North Carolina and New York. In connection with our initial public offering, we purchased a qualified North Carolina corporation (see Consolidating Transactions). To the extent we cannot adequately satisfy a state’s licensing requirements, we do not operate in that state. On December 22, 2020, the Company acquired HE Wilson Liquidations, Inc., a company incorporated on March 28, 1956 in North Carolina. Concurrent with the acquisition, the Company renamed HE Wilson Liquidations, Inc. as Bowman North Carolina Ltd. (BNCL). On December 31, 2020, the Company acquired directly the assets of DCPC and NCPC.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies The following is a summary of the significant accounting policies and principles used in the preparation of the condensed consolidated financial statements: Emerging Growth Company Section 102(b)(1) of the Jumpstart Our Business Startups Act (“JOBS Act”) exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging Revenue Recognition Accounting Standards Update (“ASU”) No. 2014-09, The Company generally recognizes revenue over time as control transfers to a customer based upon the extent of progress towards satisfaction of the performance obligation. For services delivered under fixed price contracts, the Company uses the ratio of actual costs incurred to total estimated costs at completion (an input method) as a reasonable measure of progress towards the satisfaction of a performance in order to estimate the portion of revenue earned. A contract containing a mix of hourly and fixed fee assignments may be characterized as one lump sum contract for purposes of ASC Topic 606. As such, a contract must contain hourly billed components exclusively to qualify for the as-billed Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires 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 financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could vary from the estimates and assumptions that were used. Concentration of Credit Risk and other Concentrations The Company’s financial instruments that are exposed to concentrations of credit risk consist of cash and accounts receivable. Cash balances at various times during the year may exceed the amount insured by the Federal Deposit Insurance Corporation. The Company’s cash deposits are held in institutions whose credit ratings are monitored by management, and the Company has not incurred any losses related to such deposits. The Company is subject to a concentration of credit risk with respect to outstanding accounts receivable. However, the Company believes no such concentration existed during the nine months ended September 30, 2021, or the year ended December 31, 2020. The Company’s customers are located throughout the United States. Although the Company generally grants credit without collateral, management believes that its contract acceptance, billing, and collection policies are adequate to minimize material credit risk. Also, for non-governmental non-payment. Fair Value Measurements Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosures The codification establishes a three-level disclosure hierarchy to indicate the level of judgment used to estimate fair value measurements: Level 1: Level 2: Level 3: As of September 30, 2021 and December 31, 2020: • The carrying amount of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair value due to the relatively short duration of these instruments; • The carrying amounts of debt obligations approximate their fair values as the terms are comparable to terms currently offered by local financial institutions for arrangements with similar terms to industry peers with comparable credit characteristics. Accordingly, the debt obligations involve Level 2 fair value inputs; • As of December 31, 2020 the liability related to shares subject to repurchase is recognized at fair value using Level 3 inputs that were primarily determined based on the contractual settlement price as defined by the terms of the Company’s Shareholders’ Buy-Sell Stock Bonus Plan Income Taxes The Company recognizes deferred income tax assets or liabilities for expected future tax consequences of events recognized in the consolidated financial statements or tax returns. Under this method, deferred income tax assets or liabilities are determined based upon the difference between the financial statement and income tax bases of assets and liabilities using enacted tax rates expected to apply when the differences settle or become realized. Valuation allowances are provided when it is more likely than not that a deferred tax asset is not realizable or recoverable in the future. The Company recognizes the effect of a change in tax rates on deferred tax assets and liabilities in income in the period that includes the enactment date. The Company’s effective tax rate for the nine months ended September 30, 2021 and 2020 was (18.6%) and 37.03%. The Company assesses uncertain tax positions to determine whether the position will more likely than not be sustained upon examination by the Internal Revenue Service (IRS) or other taxing authorities. If the Company cannot reach a more-likely-than-not The Company files income tax returns in the U.S. federal jurisdiction and certain states in which it operates. Based on the timing of the filing of certain tax returns, the Company’s federal income tax returns for tax years 2017 and after remain subject to examination by the U.S. Internal Revenue Service. The statute of limitations on the Company’s state income tax returns generally conforms to the federal three-year statute of limitations. Segments The Company operates in one segment based upon the financial information used by its chief operating decision maker in evaluating the financial performance of its business and allocating resources. The single segment represents the Company’s core business of providing engineering and related professional services to its customers. Recently Issued Accounting Guidance Accounting guidance not yet adopted Leases 2016-02, 2016-02”) right-of-use 2016-02 Financial Instruments—Credit Losses 2016-13, 2016-13 Goodwill 2017-04, 2017-04 2017-04	2. Significant Accounting Policies The following is a summary of the significant accounting policies and principles used in the preparation of the combined financial statements: Emerging Growth Company Section 102(b)(1) of the Jumpstart Our Business Startups Act (“JOBS Act”) exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging Adoption of new accounting standard In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, 2014-09 Revenue Recognition As discussed in Note 1, the Company provides a variety of engineering and related professional services to customers located throughout the United States. The Company enters into agreements with clients that create enforceable rights and obligations and for which it is probable that the Company will collect the consideration to which it will be entitled as services transfer to the customer. It is customary practice for the Company to have written agreements with its customers and revenue on oral or implied arrangements is generally not recognized. The Company recognizes revenue based on the consideration specified in the applicable agreement. Excluded from the transaction price are amounts collected on behalf of third parties for sales and similar taxes. Long-term contracts typically contain billing terms that provide for invoicing once a month and payment on a net 30-day As a professional services engineering firm, the Company generally recognizes revenue over time as control transfers to a customer based upon the extent of progress towards satisfaction of the performance obligation. For services delivered under fixed price contracts, the Company uses the ratio of actual costs incurred to total estimated costs since costs incurred (an input method) represent a reasonable measure of progress towards the satisfaction of a performance in order to estimate the portion of revenue earned. This method faithfully depicts the transfer of value to the customer when the Company is satisfying a performance obligation that entails a number of interrelated tasks or activities for a combined output that requires the Company to coordinate the work of employees and sub-consultants. catch-up When a performance obligation is billed using a time-and-material In certain situations, it is possible that two or more contracts should be combined and accounted for as a single contract, or a single contract should be accounted for as multiple performance obligations. This requires significant judgment and could impact the amount and timing of revenue recognition. Such determinations are made using management’s best estimate and knowledge of contracts and related performance obligations. The Company’s contracts may contain variable consideration in the form of unpriced or pending change orders or claims that either increase or decrease the contract price. Variable consideration is generally estimated using the expected value method but may from time to time be estimated using the most likely amount method depending on the circumstance. Estimated amounts are included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur or when the uncertainty associated with the variable consideration is resolved. Estimates of variable consideration are based upon historical experience and known trends. The Company recognizes claims against vendors, sub-consultants, Contract related assets and liabilities are classified as current assets and current liabilities. Significant balance sheet accounts related to the revenue cycle are as follows: Accounts receivables, net: Accounts receivable, net (contract receivables) includes amounts billed under the contract terms. The amounts are stated at their net realizable value. The Company maintains an allowance for doubtful accounts to provide for the estimated number of receivables that will not be collected. The Company considers several factors in its estimate of the allowance, including knowledge of a client’s financial condition, its historical collection experience, and other factors relevant to assessing the collectability of such receivables. Contract Assets: Contract Assets are recorded when progress to completion revenue earned on contracts exceeds amounts actually billed under the contract. It may also include contract retainages that can be billed once contract stipulations are satisfied. Contract Liabilities: Contract Liabilities are recorded when amounts actually billed under a contract exceeds the progress to completion revenue earned under the contract. Contract Cost Assets Contract acquisition costs are comprised of costs to obtain and fulfill contracts. These costs, such as pre-contract Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires 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 financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could vary from the estimates and assumptions that were used. Cash and Cash Equivalent The Company considers cash on deposit and all highly liquid investments with original maturities of three months or less when purchased to be cash and cash equivalents. Cash consists primarily of cash in accounts held at a financial institution. Certain of these accounts are designated as zero balance accounts wherein the balance is swept out nightly to reduce the Company’s line of credit balance, if any. Under the terms of the Company’s Credit Agreement, the Company’s primary lender may make advances to prevent or cover an overdraft on any of the Company’s accounts. The lender may make such advances even if the advances cause the outstanding balance to exceed the credit limit under the Credit Agreement. On the accompanying combined balance sheets at December 31, 2019 and 2020, the Company has included $1.7 million and $2.2 million, respectively, of payments in excess of cash on hand in accounts payable and accrued expenses. The total amount of such checks did not exceed the availability under the Company’s line of credit as of December 31, 2019 and December 31, 2020. Concentration of Credit Risk and other Concentrations The Company’s financial instruments that are exposed to concentrations of credit risk consist of cash and accounts receivable. Cash balances at various times during the year may exceed the amount insured by the Federal Deposit Insurance Corporation. The Company’s cash deposits are held in institutions whose credit ratings are monitored by management, and the Company has not incurred any losses related to such deposits. The Company is subject to a concentration of credit risk with respect to outstanding accounts receivable, however the Company believes no such concentration existed during the years ended December 31, 2019 and 2020. The Company’s customers are located throughout the United States. Although the Company generally grants credit without collateral, management believes that its contract acceptance, billing, and collection policies are adequate to minimize material credit risk. Also, for non-governmental non-payment. Allowance for Doubtful Accounts The Company records accounts receivable net of an allowance for doubtful accounts. The allowance is determined based upon management’s review of the estimated collectability of the specific accounts receivable, plus a general provision based upon the historical loss experience and existing economic conditions. The Company charges off uncollectible amounts against the allowance for doubtful accounts once management determines the amount, or a portion thereof, to be worthless. As of December 31, 2019, and 2020, the balance in the allowance for doubtful accounts was $0.9 million and $1.5 million, respectively. Activity in the allowance for doubtful accounts that accounts for the change in balance consisted of the following: December 31, December 31, Balance as of beginning of the year $ 883 $ 939 Provision for doubtful accounts 129 799 Write-offs of uncollectable accounts (73 ) (190 ) Balance as of the end of the year $ 939 $ 1,548 Property and Equipment Property and equipment are recorded at cost. Improvements and replacements of property and equipment are capitalized. Maintenance and repairs that do not improve or extend the lives of property and equipment are charged to expense as incurred. Upon the sale or retirement of property and equipment, the cost and related accumulated depreciation are removed from the respective accounts and any gain or loss is reported in the combined statements of operations. Depreciation is provided for using the straight-line method over the estimated useful lives as follows for the major classes of assets:​​​​​​​ Computer equipment 3 to 5 years Survey equipment 2 to 5 years Vehicles 5 years Furniture and fixtures 7 years Software 3 to 5 years Leasehold improvements the lesser of useful life or term of lease For the years ended December 31, 2019 and 2020, the Company recognized a $0.1 million and a $0.1 million gain from the disposal of certain pieces of property and equipment in connection with sale-leaseback transactions, respectively. This amount is recorded within gain on sale on the accompanying combined financial statements.​​​​​​​​​​​​​​ Business Combinations Business combinations are accounted for under the acquisition method of accounting, which requires recognition separately from goodwill, the assets acquired, and the liabilities assumed at their acquisition date fair values. While best estimates and assumptions are used to calculate the fair value assets acquired and liabilities assumed at the acquisition date as well as contingent consideration, when applicable, the estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, adjustments that are based on new information obtained about facts and circumstances that existed as of the acquisition date are recorded to the assets acquired and liabilities assumed with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recognized in the combined income statements. Goodwill and Intangible Assets The purchase price of an acquired business is allocated to the tangible assets and separately identifiable intangible assets acquired, less liabilities assumed, based upon their respective fair values with any excess purchase price over such fair values being recorded as goodwill. Goodwill and intangible assets acquired in a business combination and determined to have indefinite useful life are not amortized, but instead are reviewed for impairment annually, or more frequently if impairment indicators arise. Intangible assets with estimable useful lives are amortized over such lives and reviewed for impairment if indicators are present. The Company performs its annual impairment test as of October 1 of each year. As its business is highly integrated and its components have similar economic characteristics, the Company has concluded it has one reporting unit at the combined entity level. The Company performs a Step 1 impairment analysis by comparing the fair value of the reporting unit to carrying amount. Management engaged a third-party valuation firm to assist with the determination of fair value for the years ended December 31, 2019 and 2020. The fair value of the reporting unit derives from multiple weighted valuation techniques. If the fair value of the reporting unit is less than its carrying amount, we conduct a Step 2 impairment analysis to determine the implied fair value of the reporting unit’s goodwill. An impairment loss is recognized for the difference of the reporting unit’s implied fair value of goodwill and its carrying amount. The Company performed an impairment analysis for the years ended December 31, 2019 and 2020 and concluded that the fair value of the reporting unit was in excess of its carrying amount, and as such, no impairment was required. Definite-lived intangibles include customer relationships, contract rights, and non-compete The Company is required to review long-lived assets and definite-lived intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Recoverability of assets held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered impaired, the impairment recognized is measured by the amount by which the carrying amount of the asset exceeds its fair value. We report assets to be disposed of at the lower of the carrying amount or fair value, less cost to sell. There were no event or changes in circumstances, for the years ended December 31, 2019 and 2020, that indicated impairment of any long-lived assets. Deferred Offering Costs Upon closing of the planned initial public offering (“IPO”), deferred offering costs, consisting of legal, accounting and other fees directly related to the IPO will net against the gross proceeds. As of December 31, 2020, the Company recorded $0.9 million of deferred offering costs that are included in other assets on the accompanying combined balance sheet. Deferred Rent The Company recognizes rent expense on a straight-line basis over the term of each operating lease commencing on the date the Company takes possession of the leased premises. In addition, the Company records allowances such as free rent or improvement allowances as deferred rent in the combined balance sheets and amortizes the amount on a straight-line basis over the term of the related operating lease. Long-term incentive compensation plan The Company maintains a variable compensation plan and discretionary bonus program for employees and provides individualized long-term incentive plans to certain managers and executives. The variable compensation plan and discretionary bonus program includes cash awards and the long-term incentive plans include issuance of restricted stock grants. The Company periodically grants restricted stock awards to reward performance and incentivize retention. Stock-based Compensation Shares originating from the granting of restricted stock bonus awards, stock options and the sale of stock to employees at prices below fair value are subject to Accounting Standards Codification Topic 718, Compensation – Stock Compensation non-cash On December 22, 2020 and December 31, 2020, the Company modified its stock-based compensation agreements resulting in a change in classification of the majority of these awards from liability to equity. The modification resulted in a final fair value liability measurement and non-cash non-cash For ASC Topic 718 stock-based awards classified as permanent equity, the Company generally recognizes non-cash Non-recourse Certain stock subscription notes receivable of the Company are non-recourse. pre-paid, non-recourse Redeemable Common Shares Prior to December 22, 2020, the Company classified shares issued subject to Accounting Standards Codification 480 – Distinguishing Liabilities from Equity On December 22, 2020, the Company modified its agreements resulting in a change in classification from redeemable common stock to permanent equity. The modification resulted in a final fair value measurement of the shares subject to redemption and the effective exchange of those shares for permanent equity.​​​​​​​ Fair Value Measurements Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosures The codification establishes a three-level disclosure hierarchy to indicate the level of judgment used to estimate fair value measurements: Level 1: Quoted prices in active markets for identical assets or liabilities as of the reporting date; Level 2: Quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; and inputs other than quoted prices (such as interest rate and yield curves); Level 3: Uses inputs that are unobservable, supported by little or no market activity and reflect significant management judgment. As of December 31, 2019, and 2020: • The carrying amount of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair value due to the relatively short duration of these instruments • The carrying amounts of debt obligations approximate their fair values as the terms are comparable to terms currently offered by local financial institutions for arrangements with similar terms to industry peers with comparable credit characteristics. Accordingly, the debt obligations involve Level 2 fair value inputs. • The liability related to shares subject to repurchase is recognized at fair value using Level 3 inputs that were primarily determined based on the contractual settlement price as defined by the terms of the Company’s Shareholders’ Buy-Sell See Note 18 for further discussion. Advertising Expense The Company expenses the cost of advertising as incurred. Advertising expense was $0.1 million and $0.1 million for the years ended December 31, 2019 and 2020, respectively. Income Taxes On January 1, 2018, the Company changed it election from an S-corporation C-corporation. The Company recognizes deferred income tax assets or liabilities for expected future tax consequences of events recognized in the combined financial statements or tax returns. Under this method, deferred income tax assets or liabilities are determined based upon the difference between the financial statement and income tax bases of assets and liabilities using enacted tax rates expected to apply when the differences settle or become realized. Valuation allowances are provided when it is more likely than not that a deferred tax asset is not realizable or recoverable in the future. The Company recognizes the effect of a change in tax rates on deferred tax assets and liabilities in income in the period that includes the enactment date. The Company assesses uncertain tax positions to determine whether the position will more likely than not be sustained upon examination by the Internal Revenue Service (IRS) or other taxing authorities. If the Company cannot reach a more-likely-than-not Segments The Company operates in one segment based upon the financial information used by its chief operating decision maker in evaluating the financial performance of its business and allocating resources. The single segment represents the Company’s core business of providing engineering and related professional services to its customers. Recently Issued Accounting Guidance Accounting guidance not yet adopted Leases 2016-02, 2016-02”) right-of-use 2016-02 Financial Instruments – Credit Losses 2016-13, 2016-13 Goodwill 2017-04, 2017-04 2017-04

Earnings per Share

Earnings per Share	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings per Share	3. Earnings per Share Basic earnings (loss) per share is calculated by dividing net income (loss) attributable to the Company available to common stockholders by the weighted average number of common shares outstanding for the three and nine months ended September 30, 2021 and 2020. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were either exercised or converted into common stock or resulted in the issuance of common stock that would share in the earnings of the Company. The dilutive effect of options is reflected in diluted earnings per share by application of the treasury stock method. The dilutive effect of shares to be purchased under the Company’s Employee Stock Purchase Plan is reflected in diluted earnings per share by the weighted-average number of shares outstanding that would have been outstanding during the period. The Company uses the two-class For calculating basic earnings per share, for the three and nine months ended September 30, 2021, the weighted average number of shares outstanding exclude 2,194,343 and 1,541,174 non-vested For calculating basic earnings per share, for the three and nine months ended September 30, 2020, the weighted average number of shares outstanding exclude 310,922 and 253,141 non-vested The following table represents a reconciliation of the net income and weighted average shares outstanding for the calculation of basic and diluted earnings per share for the three and nine months ended September 30, 2021 and 2020 (in thousands, except share data): For the Three Months Ended For the Nine Months Ended 2021 2020 2021 2020 Numerator Net income (loss) $ 357 $ (1,248 ) $ 899 $ 794 Earnings allocated to non-vested 71 — 165 41 Subtotal $ 286 $ (1,248 ) $ 734 $ 753 Denominator Weighted average common shares outstanding 8,920,505 5,567,523 7,003,462 5,569,177 Effect of dilutive nominal options — — — 4,396 Effect of dilutive contingently earned shares 14,769 — 4,978 31,231 Dilutive average shares outstanding 8,935,274 5,567,523 7,008,440 5,604,804 Basic earnings (loss) per share $ 0.03 $ (0.22 ) $ 0.10 $ 0.14 Dilutive earnings (loss) per share $ 0.03 $ (0.22 ) $ 0.10 $ 0.13	3. Earnings per Share Basic earnings (loss) per share is calculated by dividing net income (loss) attributable to the Company available to common stockholders by the weighted average number of common shares outstanding for the years ended December 31, 2019 and 2020. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were either exercised or converted into common stock or resulted in the issuance of common stock that would share in the earnings of the Company. The Company uses the two-class On August 31, 2019, the Company redeemed 38,350 shares of redeemable common shares pursuant to a put right by which the redemption price exceeded fair value. The Company reduced undistributed earnings for the year ended December 31, 2019 by $8,148 to reflect this payment. For calculating basic earnings per share, for the years ended December 31, 2019, the weighted average number of shares outstanding exclude 137,706 non-vested For calculating basic earnings per share, for the years ended December 31, 2020, the weighted average number of shares outstanding exclude 268,450 non-vested The following table represents a reconciliation of the net income and weighted average shares outstanding for the calculation of basic and diluted earnings per share for the years ending December 31, 2019, and 2020: December 31, December 31, Numerator Net income 1,526 990 Deemed dividend 8 — Earnings allocated to non-vested 38 55 Subtotal $ 1,480 $ 935 Denominator Weighted average common shares outstanding 5,770,170 5,399,356 Effect of dilutive nominal options 4,809 5,162 Effect of dilutive contingently earned shares 30,857 7,700 Dilutive average shares outstanding 5,805,836 5,412,218 Basic earnings per share $ 0.26 $ 0.17 Dilutive earnings per share $ 0.25 $ 0.17

Acquisitions

Acquisitions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions	4. Acquisitions Business Combinations McFarland-Dyer & Associates, Inc. In the third quarter of 2021, the Company signed a purchase agreement to acquire McFarland-Dyer & Associates, Inc. (“MDA”), with an effective date of August 1, 2021. MDA is a landscape architectural, land planning, civil engineering and land surveying firm based in Suwanee, GA. The Company paid total consideration of $4.0 million, which was comprised of 32,143 shares of common stock, at $12.85 per share, for a total of $0.4 million, plus $3.6 million in cash, promissory note and assumed liabilities. The promissory note has a 3.25% interest rate with equal quarterly payments beginning on January 15, 2022 and ending April 15, 2024. The purchase agreement includes a contingent consideration feature, which affords the sellers the opportunity to have the promissory note increased by a maximum of $0.7 million based on certain financial performance thresholds measured quarterly from December 31, 2021 through June 30, 2022. The Company initially recorded a $57,000 liability to contingent consideration in connection with the acquisition. The Company will quarterly evaluate its estimated liability to the contingent consideration and adjust the balance if necessary. The acquisition of MDA allows Bowman to further enhance its land architectural and civil engineering competencies thereby allowing the Company to broaden its offerings and better serve its public and private sector customers. The following summarizes the preliminary calculations of the fair values of MDA assets acquired and liabilities assumed as of the acquisition date (in thousands): Total Purchase Price $ 3,967 Purchase Price Allocation: Accounts Receivable 1,033 Contract assets 410 Property and equipment, net 39 Intangible Assets 990 Other assets 34 Accounts payable and other current liabilities (70) Contract liabilities (230) Total identifiable assets $ 2,206 Goodwill 1,761 Net assets acquired $ 3,967 The purchase price allocation is based upon preliminary information and is subject to change when additional information is obtained. Goodwill results from an assembled workforce, which does not qualify for separate recognition, as well as expected future synergies from combining operations. All of the goodwill recognized is expected to be deductible for tax purposes. The Company has not completed its final assessment of the fair values of MDA’s assets acquired and liabilities assumed. The final purchase allocation could result in adjustments to certain assets and liabilities, including the residual amount allocated to goodwill. Identified intangible assets are comprised of customer relationships and contract rights for a total amount of $1.0 million, to be amortized over an estimated useful life of 15 years and 2.4 years, respectively.	4. Acquisitions Asset Acquisitions Atherton Engineering, Inc. On June 30, 2018, BCG acquired certain specified assets of Atherton Engineering, Inc. (Atherton), all of which were deemed to be intangible assets. The total purchase price was $0.4 million, which was comprised of 38,350 shares of common stock at $7.15 per share for a total of $0.2 million and contingent consideration of $0.2 million. Contingent consideration is included in accounts payable and accrued expenses in the accompanying combined balance sheet at December 31, 2019. All contingent consideration associated with the acquisition was settled for cash as of December 31, 2020. The shares of common stock issued contain put option rights at $8.47 per share that vest 12 months post closing. These option rights were exercised during the year ended December 31, 2019. Pursuant to the option agreement, the Company entered into a 30-month The Company did not acquire an input or substantive processes from Atherton that together significantly contribute the ability to create output. As such, the transaction was deemed an asset purchase, with the intangible assets recorded at their fair market value on the acquisition date. The Company identified intangible assets comprised of customer relationships of $0.1 million to be amortized over an estimated useful life of 5 years, contract rights of $0.2 million to be amortized over an estimated useful life of 2 years, and a non-compete Westland Resources, Inc. On September 30, 2018, the Company acquired certain specified assets of Westland Resources, Inc. (Westland), all of which were deemed to be intangible assets. The total purchase price was $0.7 million, which was comprised of cash of $0.1 million, 50,327 shares of common stock at $5.49 per share for a total of $0.3 million, and $0.3 million in contingent consideration based on revenue generated from acquired contracts. The Company expects to pay 100% of the contingent consideration which is included in accounts payable and accrued expenses in the accompanying combined balance sheet at December 31, 2019 and 2020. The Company did not incur any significant transaction costs for the Westland asset acquisition. The Company did not acquire an input or substantive processes from Westland that together significantly contribute the ability to create output. As such, the transaction was deemed an asset purchase, with the intangible assets recorded at their fair market value on the acquisition date. The Company identified intangible assets comprised of contract rights of $0.3 million to be amortized over an estimated useful life of 5 years, and customer relationships of $0.4 million to be amortized over an estimated useful life of 5 years. Business Combinations Bowman North Carolina Ltd. (“BNCL”) On December 22, 2020, the Company acquired 100% of the outstanding stock of HE Wilson Liquidation Inc., a dormant North Carolina corporation. Concurrent with the acquisition, the Company renamed HE Wilson Liquidation, Inc. as Bowman North Carolina Ltd. BNCL’s activities from the date of acquisition through December 31, 2020 consolidate with the operations of the Company. The Company acquired BNCL for a total purchase price of $0.3 million. BNCL had no assets, no liabilities and no operations. The allocation of the purchase price was recorded entirely to indefinite-lived intangible assets. The benefit to the Company of the acquisition was BNCL’s ability to conduct engineering and surveying operations in North Carolina, based on its original date of incorporation, without being a professional services corporation with individual ownership. There were no transaction costs other than general legal expenses included in the selling, general and administrative costs in Company’s Combined Income Statements for the year ended December 31, 2020. The Company contributed acquired contracts and operations of NCPC to BNCL post-closing. See Business Combinations – entities under common control below. Business Combinations – Entities under Common Control Bowman Consulting DC PC Since its founding in 2014, Bowman Consulting DC PC has operated as a stand-alone engineering enterprise in the District of Columbia, owned 100% by Gary Bowman, our Chairman and Chief Executive Officer. DCPC’s results were included in our combined financial statements based on common control. On December 31, 2020, the Company acquired all the assets and operations, and assumed certain liabilities of Bowman Consulting DC PC and thereafter Bowman Consulting DC PC ceased operations. In connection with the purchase, we issued 59,000 shares of common stock to Mr. Bowman recorded at the carrying amount of the net assets of DCPC or $0.7 million. Because DCPC was an entity under common control combined with the Company’s financial results, there was no impact on the Company’s combined assets, liabilities or equity from the accounting for the acquisition or the issuance of the stock to Mr. Bowman. Bowman Consulting NC PC Since its founding in 2019, Bowman Consulting NC PC has operated as a stand-alone engineering enterprise in the North Carolina, owned 90% by Gary Bowman, our Chairman and Chief Executive Officer, 5% by Mike Bruen, our Chief Operating Officer, and 5% by another shareholder of the Company. NCPC’s results were included in our combined financial statements based on common control. On December 31, 2020, the Company acquired all the assets and operations, and assumed certain liabilities of Bowman Consulting NC PC and thereafter Bowman Consulting NC PC ceased operations. In connection with the purchase, the Company issued 4,632 shares of common stock to the sellers, recorded at the carrying amount of the net assets of NCPC or $4,400. Because NCPC was an entity under common control combined with the Company’s financial results, there was no impact on the Company’s combined assets, liabilities or equity from the accounting for the acquisition or the issuance of the stock to the sellers. After closing, the Company contributed the assets and operations acquired from Bowman Consulting NC PC into Bowman North Carolina Ltd. ( See Business Combinations above).

Disaggregation of Revenue and C

Disaggregation of Revenue and Contract Balances	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Disaggregation of Revenue [Abstract]
Disaggregation of Revenue and Contract Balances	5. Disaggregation of Revenue and Contract Balances The Company generally recognizes revenue over time as control transfers to a customer based upon the extent of progress towards satisfaction of the performance obligation. For services delivered under fixed price contracts, the Company uses the ratio of actual costs incurred to total estimated costs at completion (an input method) as a reasonable measure of progress towards the satisfaction of a performance in order to estimate the portion of revenue earned. A contract containing a mix of hourly and fixed fee assignments may be characterized as one lump sum contract for purposes of ASC Topic 606. As such, a contract must contain hourly billed components exclusively to qualify for the as-billed The Company recognized $0.1 million and $1.3 million of revenue for the three and nine months ended September 30, 2021, which was included in the contract liabilities balance as of December 31, 2020 and $0.4 million and $4.5 million of revenue for the three and nine months ended September 30, 2020, which was included in the contract liabilities balance as of December 31, 2019.	5. Disaggregation of Revenue and Contract Balances Contracts are considered lump sum and evaluated for cost-basis percentage completion revenue calculation if any of the components of the contract are subject to fixed fee or unit pricing. As such, a lump sum contract may contain a mix of hourly and fixed fee components. A contract must contain hourly billed components exclusively to qualify for the as-billed The Company recognized $32.7 million of revenue for the year ended December 31, 2019, which was included in the contract liabilities balance as of December 31, 2018 and $32.8 million of revenue for the year ended December 31, 2020, which was included in the contract liabilities balance as of December 31, 2019.

Contracts in Progress

Contracts in Progress	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Contracts in Progress	6. Contracts in Progress The following table reflects the calculation of the net balance of contract assets and contract liabilities. Costs and estimated earnings on contracts in progress consist of the following (in thousands): September 30, 2021 December 31, 2020 Costs incurred on uncompleted contracts $ 148,335 $ 113,856 Estimated contract earnings in excess of costs 198,528 151,423 Estimated contract earnings to date 346,863 265,279 Less: billed to date (340,753 ) (260,142 ) Net contract assets $ 6,110 $ 5,137	6. Contracts in Progress The following table reflects the calculation of the net balance of contract assets and contract liabilities. Costs and estimated earnings on contracts in progress consist of the following (in thousands): December 31, December 31, Costs incurred on uncompleted contracts $ 112,417 $ 113,856 Estimated contract earnings in excess of costs 160,242 151,423 Estimated contract earnings to date 272,659 265,279 Less: billed to date (270,439 ) (260,142 ) Net contract assets $ 2,220 $ 5,137

Notes Receivable

Notes Receivable	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Receivables [Abstract]
Notes Receivable	7. Notes Receivable The Company has unsecured notes receivable from related parties, certain non-executive September 30, 2021 December 31, 2020 Officers, employees and affiliated entities—Interest accrues annually at rates ranging from 3.25%—5.5%. The notes receivable mature through December 2021 $ 2,393 $ 2,479 Unrelated third party—Currently no interest is being accrued on this note. The note receivable matures in December 2023 903 903 Total: 3,296 3,382 Less: current portion Officers, employees and affiliates (1,120 ) (1,182 ) Unrelated third party — — Noncurrent portion $ 2,176 $ 2,200 Each borrower may prepay all or part of the outstanding balance at any time prior to the date of maturity. During the nine months ended September 30, 2021, interest accrued on the notes receivable at the stipulated rates between 3.25% and 5.50%.	7. Notes Receivable The Company has unsecured notes receivable from related parties including certain officers of the Company and from an unrelated third party. This balance is included as a part of other assets on the accompanying combined balance sheets. The following is a summary of these notes receivable (in thousands): December 31, December 31, Officers, employees and affiliated entities - Interest accrues annually at rates ma December 2021 $ 8,995 $ 2,479 Unrelated third party - Interest accrues annually at an interest rate of December 2023 904 903 Total 9,899 3,382 Less: current portion Officers, employees and affiliates (525 ) (1,182 ) Unrelated third party (904 ) (— ) Noncurrent portion $ 8,470 $ 2,200 Each borrower may prepay all or part of the outstanding balance at any time prior to the date of maturity. During the years ended December 31, 2019 and 2020, interest accrued on three of the notes receivable at the stipulated rates of 3.50% and 4.00%.

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	8. Property and Equipment, Net Property and equipment for fixed assets are as follows (in thousands): September 30, 2021 December 31, 2020 Computer equipment $ 1,260 $ 1,276 Survey equipment 4,444 4,444 Vehicles 460 463 Furniture and fixtures 1,661 1,638 Leasehold improvements 6,727 5,887 Software 283 283 Fixed assets pending lease financing 1 351 146 Total: 15,186 14,137 Less: accumulated depreciation (10,460 ) (9,912 ) Property and Equipment, net of capital leased assets $ 4,726 $ 4,225 1 assets acquired which will be re-financed Depreciation expense for fixed assets for the three and nine months ended September 30, 2021 was $0.2 million and $0.6 million, respectively. Depreciation expense for fixed assets for the three and nine months ended September 30, 2020 was $0.2 million and $0.6 million, respectively. Property and equipment for capital leased assets are as follows (in thousands): September 30, 2021 December 31, 2020 Equipment $ 13,393 $ 8,590 Vehicles 4,516 3,825 Total: 17,909 12,415 Less: accumulated amortization on leased assets (4,771 ) (1,283 ) Capital Leased Assets, net $ 13,138 $ 11,132 Amortization expense for capital leased assets for the three and nine months ended September 30, 2021 was $1.3 million and $3.7 million, respectively. Amortization expense for capital leased assets for the three and nine months ended September 30, 2020 was $0.1 million and $0.2 million, respectively.	8. Property and Equipment, Net Property and equipment for fixed assets are as follows (in thousands): December 31, December 31, Computer equipment 1,427 1,276 Survey equipment 4,444 4,444 Vehicles 473 463 Furniture and fixtures 1,628 1,638 Leasehold improvements 4,635 5,887 Software 283 283 Fixed asset inventory 488 146 13,378 14,137 Less: accumulated depreciation (9,330 ) (9,912 ) Property and Equipment, net 4,048 4,225 Depreciation expense for fixed assets for the years ended December 31, 2019 and 2020 was $513 and $746, respectively. On September 30, 2020, the Company converted substantially all of its operating leases for equipment and automobiles to capital leases. Property and equipment for capital leased assets are as follows (in thousands): December 31, December 31, Equipment $ 722 $ 8,590 Vehicles — 3,825 722 12,415 Less: accumulated amortization on leased assets — (1,283 ) Capital Leased Assets, net $ 722 $ 11,132 Amortization expense for capital leased assets for the years ended December 31, 2019 and 2020 was $0 and $1.3 million, respectively.​​​​​​​

Goodwill

Goodwill	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	9. Goodwill The following is a summary of goodwill resulting from business acquisitions held by the Company at September 30, 2021 and December 31, 2020 (in thousands): Goodwill Balance as of December 31, 2020 $ 9,179 Acquisition—KTA Group 2,544 Acquisition—McFarland-Dyer & Associates 1,761 Balance as of September 30, 2021 $ 13,484	9. Goodwill The following is a summary of goodwill resulting from business acquisitions held by the Company at December 31, 2019 and 2020 (in thousands): December 31, December 31, Goodwill $ 9,179 $ 9,179

Intangible Assets

Intangible Assets	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Intangible Assets [Abstract]
Intangible Assets	10. Intangible Assets Total intangible assets consisted of the following at September 30, 2021 and December 31, 2020 (in thousands): September 30, 2021 December 31, 2020 Gross Accumulated Net Gross Accumulated Net Customer relationships $ 2,192 $ (534 ) $ 1,658 $ 809 $ (382 ) $ 427 Contract rights 488 (185 ) 303 150 (150 ) — Leasehold 160 (13 ) 147 — — — Non-complete 137 (137 ) — 137 (114 ) 23 Domain name 281 — 281 281 — 281 Licensing rights 400 — 400 400 — 400 Total $ 3,658 $ (869 ) $ 2,789 $ 1,777 $ (646 ) $ 1,131 The domain name and licensing rights acquired during the year ended December 31, 2020 for a total of $0.7 million have indefinite useful lives. The following table summarizes the weighted average useful lives of intangible assets by asset class used for straight-line expense purposes: September 30, December 31, Customer relationships 12.8 5.0 Contract rights 2.4 2.0 Leasehold 9.2 — Non-compete 3.0 3.0 Amortization expense for the three and nine months ended September 30, 2021 was $0.1 million and $0.2 million, respectively. Amortization expense for the three and nine months ended September 30, 2020 was $0.1 million and $0.2 million, respectively. Future amortization for the remainder of 2021 and for the succeeding years is as follows (in thousands): 2021 $ 100 2022 397 2023 336 2024 102 2025 102 Thereafter 1,071 Total $ 2,108	10. Intangible Assets Total intangible assets consisted of the following at December 31, 2019 and December 31, 2020 (in thousands): December 31, 2019 December 31, 2020 Gross Accumulated Net Gross Accumulated Net Customer relationships $ 809 $ (225 ) $ 584 $ 809 $ (382 ) $ 427 Contract rights 150 (112 ) 38 150 (150 ) — Non-complete 137 (68 ) 69 137 (114 ) 23 Domain name — — — 281 — 281 Licensing rights — — — 400 — 400 Total $ 1,096 $ (405 ) $ 691 $ 1,777 $ (646 ) $ 1,131 The domain name and licensing rights acquired during the year ended December 31, 2020 for a total of $0.7 million have indefinite useful lives. The following table summarizes the weighted average useful lives of intangible assets by asset class used for straight-line expense purposes:​​​​​​​ December 31, December 31, Customer relationships 4.98 4.98 Contract rights 2.0 2.0 Non-compete 3.0 3.0 Amortization expense for the year ended December 31, 2019 and 2020 was $0.3 million and $0.2 million, respectively. Actual and future amortization is as follows for the years ending December 31 (in thousands): 2021 $ 181 2022 158 2023 111 Total $ 450

Bank Revolving Line of Credit a

Bank Revolving Line of Credit and Fixed Credit Facilities	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Line of Credit Facility [Abstract]
Bank Revolving Line of Credit and Fixed Credit Facilities	11. Bank Revolving Line of Credit and Fixed Credit Facilities In 2017, the Company entered into a credit agreement (“the Credit Agreement”) with Bank of America (“the Bank”) which included a revolving line of credit (“the Revolving Line”) and a non-revolving re-borrowings. During the year ended December 31, 2019, the Credit Limit increased to $15.0 million. During the year ended December 31, 2019, a second non-revolving On July 30, 2021, the Company entered into a Sixth Amendment to the Credit Agreement whereby the Company and the Bank agreed to extend the maturity date of the Revolving Line to July 31, 2023. The Sixth Amendment also eliminated the adjusted debt to EBITDA covenant along with certain administrative requirements and established the Secured Overnight Financing Rate (SOFR) as the replacement for LIBOR. Additional modifications to the Revolving Line included expanded allowances for acquisition and reduced interest rate spreads to a range of 2.00% to 2.60%, among other things. As of June 30, 2021, the Revolving Line required monthly payments of interest at the greater of the London Interbank Offered Rate (LIBOR) daily floating rate or 1.25% plus an applicable rate which varied between 2.35% and 2.95% based on the Company achieving certain leverage ratios as defined in the Credit Agreement. On September 30, 2021, and September 30, 2020, the interest rate was 3.60% and 3.25%, respectively. All outstanding principal is due upon expiration, which was extended to July 31, 2023, when the Company entered into the Sixth Amendment to the Credit Agreement. The Revolving Line is reported as bank line of credit on the consolidated balance sheets. On September 30, 2021 and December 31, 2020, the outstanding balance on the Revolving Line was $0 and $3.5 million, respectively. Fixed Line #1 has a maximum advance of $1.0 million and does not allow for re-borrowings August 2023 Fixed Line #2 has a maximum advance of $1.0 million and does not allow for re-borrowings September 2025 Facility #4 is a term loan with a principal loan amount of $1.0 million and is included in Notes Payable (see Note 12). The loan is to be repaid over thirty-six The Company secures its obligations under the Credit Agreement with substantially all assets of the Company. Fixed Line #1 is guaranteed by Gary Bowman, the Company’s Chairman and Chief Executive Officer (“Guarantor”). Obligations of the Company to the Guarantor and certain other shareholders of the Company are subordinated to the Company’s obligations under the Credit Agreement and Fixed Line loans. The Company must maintain, on a combined basis certain financial covenants defined in the Credit Agreement. Interest expense on the Revolving and Fixed Lines totaled $12,000 and $0.1 million during the three and nine months ended September 30, 2021. Interest expense on the Revolving and Fixed Lines totaled $35,000 and $0.2 million during the three and nine months ended September 30, 2020.	11. Lines of Credit In 2017, the Company entered into a credit agreement (the Credit Agreement) with Bank of America (the Bank) which included a revolving line of credit (the Revolving Line) and a non-revolving re-borrowings. During the year ended December 31, 2019, the Credit Limit increased to $15.0 million. During the year ended December 31, 2019, a second non-revolving The Revolving Line requires monthly payments of interest at the London Interbank Offered Rate (LIBOR) daily floating rate plus an applicable rate which varies between 2.35% and 2.95% based on the Company achieving certain leverage ratios as defined in the Credit Agreement. On December 31, 2019 and December 31, 2020, the interest rate was 3.79% and 3.60%, respectively. All outstanding principal is due upon expiration, which is July 31, 2021 unless the agreement is renewed, or an event of default occurs. The Revolving Line is reported as line of credit on the combined balance sheets. Fixed Line #1 has a maximum advance of $1.0 million and does not allow for re-borrowings Fixed Line #2 has a maximum advance of $1.0 million and does not allow for re-borrowings Facility #4 is a term loan with a principal loan amount of $1.0 million and is included in Notes Payable (see Note 14). The loan is to be repaid over thirty-six The Company secures its obligations under the Credit Agreement with substantially all assets of the Company. DCPC, NCPC and BNY pledge their accounts receivable to the Bank as collateral for the Credit Agreement. Fixed Line #1 is guaranteed by Gary Bowman, the Company’s controlling shareholder (“Guarantor”). Obligations of the Company to the Guarantor and certain other shareholders of the Company are subordinated to the Company’s obligations under the Credit Agreement and Fixed Line loans. The Company must maintain, on a combined basis certain financial covenants defined in the Credit Agreement. Interest expense on the Revolving and Fixed Lines totaled $0.4 million and $0.3 million during the years ended December 31, 2019 and 2020.

Notes Payable

Notes Payable	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Debt Instruments [Abstract]
Notes Payable	12. Notes Payable Notes payable consist of the following (in thousands): September 30, December 31, Related parties: Shareholders—Interest accrues annually at rates ranging from 0.00%—6.25%. The notes payable mature on various dates through October 2025. $ 4,767 $ 2,202 Unrelated third parties: Note payable for purchase of intangible asset 150 — Fixed line notes payable—see note 11 1,682 2,219 Total 6,599 4,421 Less: current portion (2,222 ) (1,592 ) Noncurrent portion $ 4,377 $ 2,829 The Company’s chairman and Chief Executive Officer guarantees certain of the notes payable, and certain of the notes payable are subordinate to the terms of the Credit Agreement disclosed in Note 11. Interest expense attributable to the notes payable totaled $0.1 million and $0.2 million for the three and nine months ended September 30, 2021, respectively. Interest expense attributable to the notes payable totaled $0.1 million and $0.2 million for the three and nine months ended September 30, 2020, respectively. Future principal payments on notes payable for remainder of 2021 and succeeding years are as follows (in thousands): 2021 $ 744 2022 2,276 2023 1,932 2024 1,286 2025 361 Total $ 6,599	12. Notes Payable Notes payable consist of the following (in thousands): December 31, December 31, Related parties: BCG Chantilly, LLC - Interest accrues annually at 12.00%; payable in varying semi-annual installments of principal and interest through maturity in October 2021. This note was paid in full September 30, 2020. 225 — Shareholders - Interest accrues annually at rates ranging from 0.00% - 6.25%. The notes payable mature on various dates through October 2025. 2,085 2,202 Unrelated third parties: Settlement notes payable - see below 625 — Fixed line notes payable - see note 11 725 2,219 Total 3,660 4,421 Less: current portion 1,744 1,592 Noncurrent portion $ 1,916 $ 2,829 A note payable was issued in 2019 for $1.3 million in conjunction with the legal settlement of a non-core A note payable was issued in 2018 in conjunction with a non-core The Company’s controlling shareholder guarantees certain of the notes payable, and certain of the notes payable are subordinate to the terms of the Credit Agreement disclosed in Note 11. Interest expense attributable to the notes payable totaled $0.2 million and $0.2 million for the years ended December 31, 2019 and 2020, respectively. Actual and estimated future principal payments on notes payable are as follows for the years ending December 31 (in thousands): 2021 $ 1,592 2022 1,263 2023 886 2024 464 2025 216 Total $ 4,421

Stock Subscription Notes Receiv

Stock Subscription Notes Receivable	12 Months Ended
	Dec. 31, 2020
Stock Subscription Notes Receivable [Abstract]
Stock Subscription Notes Receivable	13. Stock Subscription Notes Receivable Periodically, the Company offers certain key employees the opportunity to purchase shares of the Company’s common stock. Typically, the subscribed shares are financed by the Company and such shares will be issued in the name of the subscriber with the Company retaining possession of, as well as a security interest in, all share certificates until such time as each promissory note is repaid by the subscriber. Promissory note payments include principal plus interest ranging from 3.25% to 4.75% or the Wall Street Journal prime rate. During the years ended December 31, 2019 and 2020, the Company issued $6,683 and $0.5 million, respectively, of stock subscription notes receivable and received $0.2 million and $0.2 million of principal payments from the subscriber, respectively. On December 31, 2019 and 2020, eighteen and seventeen shareholders owed the Company a combined total of $0.3 million and $0.6 million, respectively, in outstanding principal. These balances are reported as a reduction to redeemable common stock on December 31, 2019 and as a reduction to shareholders’ equity on December 31, 2020.

Related Party Transactions

Related Party Transactions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	13. Related Party Transactions The Company leases commercial office space from BCG Chantilly, LLC (BCC), an entity in which Mr. Bowman, Mr. Bruen and Mr. Hickey collectively own a 63.6% interest. As of September 30, 2021 and December 31, 2020 there were no amounts due to or receivables due from BCC. Rent expense for the three and nine months ended September 30, 2021 was $21,000 and $61,000, respectively. Rent expense for the three and nine months ended September 30, 2020 was $20,000 and $60,000, respectively. Bowman Lansdowne Development, LLC (BLD) is an entity in which Mr. Bowman, Mr. Bruen, Mr. Hickey have an ownership interest. On September 30, 2021 and December 31, 2020, the Company’s notes receivable included $0.5 million and $0.5 million, respectively, from BLD. Lansdowne Development Group, LLC (LDG) is an entity in which BLD has a minority ownership interest. On September 30, 2021 and December 31, 2020, our accounts receivable included $0.1 million and $0.1 million, respectively, due from LDG. On September 30, 2021 and December 31, 2020, notes receivable included $0.4 million and $0.4 million, respectively from LDG. Bowman Realty Investments 2010, LLC (BR10) is an entity in which Mr. Bowman, Mr. Bruen, Mr. Hickey have an ownership interest. On September 30, 2021 and December 31, 2020, the Company’s notes receivable included $0.2 million and $0.2 million, respectively, from BR10. Alwington Farm Developers, LLC (AFD) is an entity in which BR10 has a minority ownership interest. On September 30, 2021 and December 31, 2020, notes receivable included $1.2 million and $1.2 million, respectively, from AFD. During the nine months ended September 30, 2021 and 2020, the Company provided administrative, accounting and project management services to certain of the related party entities. The cost of these services was $0.1 million and $0, respectively. These entities were billed $0.1 million and $0, respectively. Bowman Realty Investments 2013 LLC (BR13) is an entity in which Mr. Bowman, Mr. Bruen, and Mr. Hickey have an ownership interest. Leesburg Acquisition Partners (LAP) is an entity in which Mr. Bowman, Mr. Bruen and Mr. Hickey have an ownership interest. During the three months ended September 30, 2021, the Company made $28,808 of back charge payments relating to work performed for LAP in prior years. On September 30, 2021 and December 31, 2020, the Company was due $0.4 million and $0.6 million, respectively, from shareholders under the terms of stock subscription notes receivable. On September 30, 2021 and December 31, 2020, the Company owed $0.3 million and $0.3 million, respectively, to a retired shareholder and former director in connection with a 2015 acquisition. As of September 30, 2021 and December 31, 2020, the Company owed certain of our current and former shareholders $4.8 million and $2.2 million, respectively. The notes result from repurchases of stock from shareholders upon termination of employment and promissory notes issued in connection with acquisitions.	14. Related Party Transactions The Company leases commercial office space from BCG Chantilly, LLC (BCC), an entity in which Mr. Bowman, Mr. Bruen and Mr. Hickey collectively own a 63.6% interest. On December 31, 2019, notes payable included $0.2 million owed to BCC unrelated to the lease. The Company repaid the note in full with accrued interest on September 30, 2020. Bowman Lansdowne Development, LLC (BLD) is an entity in which Mr. Bowman, Mr. Bruen, Mr. Hickey have an ownership interest. On December 31, 2019, and 2020, the Company’s notes receivable included $0.5 million and $0.5 million, respectively, from BLD. Lansdowne Development Group, LLC (LDG) is an entity in which BLD has a minority ownership interest. On December 31, 2019, and 2020, our accounts receivable included $0.2 million and $0.1 million, respectively, due from LDG. On December 31, 2019, and 2020, notes receivable included $0.2 million and $0.4 million, respectively from LDG. Bowman Realty Investments 2010, LLC (BR10) is an entity in which Mr. Bowman, Mr. Bruen, Mr. Hickey have an ownership interest. On December 31, 2019, and 2020, the Company’s notes receivable included $0.2 million and $0.2 million, respectively, from BR10. Alwington Farm Developers, LLC (AFD) is an entity in which BR10 has a minority ownership interest. On December 31, 2019, the Company’s accounts receivable included $0.4 million due from AFD. On December 31, 2020 there was no balance in accounts receivable due from AFD. On December 31, 2019, and 2020, notes receivable included $1.2 million and $1.2 million, respectively, from AFD. During the years ended December 31, 2019, and 2020, the Company provided administrative and accounting services to certain of the related party entities at no cost. The Company employed Gregory Bowman, the son of Mr. Bowman, as a full-time employee. The Company paid Gregory Bowman $0.1 million and $0.1 million for the years ended December 31, 2019 and 2020, respectively. Bowman Realty Investments 2013 LLC (BR13) is an entity in which Mr. Bowman, Mr. Bruen, and Mr. Hickey have an ownership interest. For the years ended December 31, 2019, and 2020, an employee of the Company served as project manager for a real estate development project in which BLD, BR13, and during a portion of 2020 an entity owned and controlled by Mr. Bowman and his family have an ownership interest. The cost of the services provided for the years ended December 31, 2019, and 2020 were $0.1 million and $0.1 million, respectively. After the effectiveness of this offering, the Company will no longer provide these services at no cost to the project. As of December 31, 2019, the Company had $0.8 million of unsecured advance to Mr. Bowman included in other assets. Mr. Bowman repaid the advance in full with accrued interest on September 29, 2020 through the redemption of our stock. As of December 31, 2019, the Company had notes receivable from Mr. Bowman and Mr. Labovitz in the amounts of $5.4 million and $0.5 million, respectively. Both Mr. Bowman and Mr. Labovitz repaid their notes in full with accrued interest on September 29, 2020 through the redemption of our stock. On December 31, 2019, and 2020, the Company was due $0.3 million and $0.6 million, respectively, from shareholders under the terms of stock subscription notes receivable. On December 31, 2019, and 2020, the Company owed $0.3 million and $0.3 million, respectively, to a retired shareholder and former director in connection with a 2015 acquisition. As of December 31, 2019, and 2020, the Company owed certain of our current and former shareholders $2.0 million and $2.2 million, respectively. The notes result from repurchases of stock from shareholders upon termination of employment.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	15. Income Taxes The provision for income taxes consisted of the following (in thousands): December 31, December 31, Current expense: Federal $ 280 $ 1 State 326 662 Total 606 663 Deferred expense (benefit): Federal 468 404 State (36 ) (78 ) Total 432 326 Provision for income taxes $ 1,038 $ 989 The Company measures deferred tax assets and liabilities based on the difference between the financial statement and tax bases of assets and liabilities at the applicable tax rates. Components of the Company’s deferred tax asset and liability are as follows (in thousands):​​​​​​​ December 31, December 31, Deferred tax assets: Research and development credit carryover $ 275 $ 1,557 Deferred rent expense 1,002 1,073 Intangible asset amortization 78 23 1,355 2,653 Deferred tax liabilities: Fixed asset depreciation (375 ) (2,866 ) Accrual to cash adjustments (6,249 ) (5,398 ) Goodwill amortization (777 ) (861 ) (7,401 ) (9,125 ) Net deferred tax liabilities ($ 6,046 ) ($ 6,472 ) Based on the Company’s operating history and management’s expectation regarding future profitability, management believes the Company’s deferred tax assets will be realizable under ASC 740, Income Taxes. Accordingly, no valuation allowance exists as of December 31, 2019 and 2020. Income tax expense differed from the amounts computed by applying the federal statutory income tax rate of 21% to pretax income due to the following adjustments (in thousands): December 31, 2019 December 31, 2020 Statutory Rate $ 528 $ 410 State income taxes, net of federal benefit 76 69 Effective rate differential for DCPC—S-corp 81 (59 ) State income tax rate change 83 77 Permanent differences 97 68 Stock repurchase liability 1,078 1,474 Valuation Allowance — 27 Change in tax status — 170 Other 53 42 Research & development credit (958 ) (1,289 ) Provision for income tax $ 1,038 $ 989 The adjustment to the statutory rate from state income tax rates for the year ended December 31, 2019 are the result of changes in apportionment of revenue with a higher percentage of the Company’s revenue being derived from states with higher state rates such as Illinois. The adjustment to the statutory rate from state income tax rates for the year ended December 31, 2020 are the result of the DCPC acquisition and the impact it had on state rates. The adjustment to the statutory rate from stock purchase liability changes for the years ended December 31, 2019, and 2020 are the result of permanent differences created by the recognition of non-cash The adjustment to the statutory rate from research and development credits for the year ended December 31, 2019, and 2020 are the result of application of research and development tax credits annually earned by the Company in connection with certain at-risk The Company files income tax returns in the U.S. federal jurisdiction and certain states in which it operates. The Company’s federal income tax returns for tax years 2017 and after remain subject to examination by the U.S. Internal Revenue Service. The statute of limitations on the Company’s state income tax returns generally conforms to the federal three-year statute of limitations. On March 27, 2020, the President of the United States signed into law the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”). The CARES Act, among other things, includes provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The Company has assessed the impact of the CARES Act and we do not expect there to be a material impact to our income tax expense.

Employee Retirement Plan

Employee Retirement Plan	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Employee Retirement Plan	16. Employee Retirement Plan The Company maintains a tax-deferred For the years ended December 31, 2019 and 2020, employer contributions totaled $1.1 million and $1.3 million, respectively.

Stock Options

Stock Options	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Options	14. Stock Options Effective May 11, 2021 the Company established the Bowman Consulting Group Ltd. 2021 Omnibus Equity Incentive Plan (“the Plan”). The plan is administered by the Board of Directors through which they can grant stock options, including Incentive Stock Options (“ISO”), and non-qualified The number of shares for which each option shall be granted, whether the option is an ISO or NQSO, the option price, the exercisability of the option, and all other terms and conditions of the option are determined by the Board at the time the option is granted. The options generally vest over a period between two For the nine months ended September 30, 2021, no new option shares were granted. A summary of the status of stock options exercised, including the substantive options discussed in Note 3, is as follows: Number of shares Weighted Average Exercise Price Outstanding at January 1, 2021 53,277 $ 5.87 Granted — — Exercised (33,276 ) 5.64 Expired or cancelled — — Outstanding at September 30, 2021 20,001 $ 6.25 The following summarizes information about options outstanding and exercisable at January 1, 2021 and September 30, 2021: Options Outstanding and Exercisable Exercise Price Total Outstanding Weighted Average Remaining Life (Years) Weighted Average Exercise Price Total Exercisable January 1, 2021 $ 6.37 53,277 4.5 $ 5.87 53,277 September 30, 2021 $ 6.57 20,001 5.0 $ 6.25 20,001 The intrinsic value of these options on September 30, 2021 and December 31, 2020 was $7.18 and $6.43, respectively. The Company received cash payments of $14,855 and $42,140 from the exercise of options under the Stock Option Plan in the three and nine months ended September 30, 2021. The Company did not record any compensation costs related to stock options during the three and nine months ended September 30, 2021. As of September 30, 2021, there is no unrecognized compensation costs related to non-vested non-recourse pre-paid,	17. Stock Options In 2001, the Company established the Bowman Consulting Group Ltd. Stock Option Plan (the Stock Option Plan), which allows for issuance of Incentive Stock Options (ISO) and Non-Qualified The number of shares for which each option shall be granted, whether or not the option is an ISO or NQSO, the option price, the exercisability of the option, and all other terms and conditions of the option are determined by the Board at the time the option is granted. The options generally vest over a period between two For the year ended December 31, 2019 and 2020, 111,982 and 7,434 NQSOs were granted, respectively, including both nominal and substantive options. Options are valued using the Black-Scholes-Merton Option Pricing Model. The assumptions used to value the options granted include:​​​​​​​ December 31, December 31, Expected volatility 39.0 % 25.0 % Expected dividend yield 0.0 % 0.0 % Expected option term (in years) 2.5 5.0 Risk-free interest rate 2.6 % 2.5 % The expected volatility of the options granted was estimated using the historical volatility of share prices of publicly traded companies within the same or similar industry as a substitute for the historical volatility of the Company’s common shares, which is not determinable without an active external or internal market. The expected dividends are based on the Company’s historical estimated issuance and management’s expectations for dividend issuance in the future. The expected term of options granted represents the expected period of time for which options granted remain outstanding. The risk-free interest rate for periods within the expected life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. A summary of the status of stock options granted, including the substantive options discussed in Note 3, is as follows: Number Weighted Outstanding at January 1, 2019 2,950 0.34 Granted 111,982 3.15 Exercised (55,578 ) 0.58 Expired or cancelled (2,950 ) 0.34 Outstanding at December 31, 2019 56,404 $ 5.68 Granted 7,434 7.34 Exercised (10,561 ) 5.92 Expired or cancelled — — Outstanding at December 31, 2020 53,277 $ 5.87 The following summarizes information about options outstanding and exercisable at December 31, 2019 and December 31, 2020: Options Outstanding and Exercisable Exercise Total Weighted Weighted Total December 31, 2019 $ 6.00 56,404 4.5 $ 5.68 56,404 December 31, 2020 $ 6.37 53,277 4.5 $ 5.87 53,277 The intrinsic value of these options on December 31, 2019 and December 31, 2020 was $89.59 and $189.77, respectively. The Company recorded $121,248 and $22,443 of compensation cost related to stock options associated with the issuance of non-recourse, The Company received cash payments of $32,555 and $62,907 from the exercise of options under the Stock Option Plan in the years ended December 31, 2019 and 2020, respectively. As of December 31, 2019 and 2020, the total unrecognized compensation costs related to non-vested

Stock Bonus Plan

Stock Bonus Plan	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Bonus Plan	15. Stock Bonus Plan Effective May 11, 2021 the Company established the Bowman Consulting Group Ltd. 2021 Omnibus Equity Incentive Plan. The Plan is administered by the Board of Directors through which they can issue restricted stock awards. The purpose of the Plan is to grant equity incentive awards to eligible participants to attract, motivate and retain key personnel. The Plan supersedes and replaces any prior plan for stock bonus grants to employees of the Company except that the prior plan shall remain in effect with respect to awards granted under such prior plan until such awards have been forfeited or fully vested. During the nine months ended September 30, 2021, the Board granted 1,603,423 shares under the Plan. The shares have a vesting period of up to five years during which there are certain restrictions as defined by the Plan and Stock Bonus Agreements. The grant date fair value of the award is the closing price of the Share on such date, or if there are no sales on such date, on the next preceding day on which there were sales. The following table summarizes the activity of restricted shares subject to forfeiture: Number of shares Weighted Average Grant Price Outstanding at January 1, 2021 702,926 $ 12.80 Granted 1,603,423 13.95 Vested (96,527 ) 12.80 Cancelled (108 ) 13.02 Outstanding at September 30, 2021 2,209,714 $ 13.63 The following table represents the change in the liability to common shares subject to repurchase and the associated non-cash September 30, 2021 December 31, 2020 Beginning Balance $ 842 $ 8,267 Non-cash 41 2,712 Non-cash 2 2,457 Other stock activity, net 516 (786 ) Reclassification upon modification (1,394 ) (11,808 ) Ending balance $ 7 $ 842 As of September 30, 2021, the Company had 2,209,714 of unvested stock awards that vest between October 1, 2021 and May 11, 2026. The future expense of the unvested awards for the remainder of 2021 and succeeding years is as follows (in thousands): 2021 $ 2,527 2022 8,652 2023 7,378 2024 4,545 Thereafter 1,547 Total $ 24,649	18. Stock Bonus Plan Effective April 2003, the Company adopted the Bowman Consulting Group Ltd. Stock Bonus Plan (the Stock Bonus Plan), which allows for the awarding of shares of common stock to employees. The Stock Bonus Plan is administered by the Board of Directors (the “Board”). The Board has sole discretion to establish the terms, restrictions, size, and type of award to be granted and to whom it will grant. The Board also periodically defines or restricts the maximum number of shares it will award in each period. During the years ended December 31, 2019 and 2020, the Board granted 47,141 and 657,673 shares, respectively. The shares have a vesting period of up to four years during which there are certain restrictions as defined by the Stock Bonus Plan and Stock Bonus Agreements. The grant date fair value of the Company’s shares, as determined by a third-party valuation and approved by the Board at the time of award ranged from $5.49 to $12.80, per share during the years ended December 31, 2019 and 2020. The following table summarizes the activity of restricted shares subject to forfeiture: Number of Weighted Outstanding at January 1, 2019 188,948 5.48 Granted 47,141 5.91 Vested (77,438 ) 5.52 Cancelled (2,242 ) 5.49 Outstanding at December 31, 2019 156,409 5.59 Granted 657,673 11.00 Vested (108,206 ) 6.49 Cancelled (2,950 ) 5.49 Outstanding at December 31, 2020 1 702,926 10.51 Outstanding at December 31, 2020, as modified 2 702,926 12.80 1 Weighted average grant price at December 31, 2020 represents the grant date fair value of Stock Awards as originally issued. 2 Weighted average grant price at December 31, 2020, as modified, represents the as adjusted fair value of the outstanding Stock Awards on the date of modification in connection with the settlement of the liability to common shares subject to repurchase. The following table represents the change in the liability to common shares subject to repurchase and the associated non-cash December 31, December 31, 2019 2020 Beginning balance $ 4,464 $ 8,267 Non-cash 1,468 2,712 Non-cash 2,335 2,457 Other stock activity, net — (786 ) Reclassification upon modification — (11,808 ) Ending balance $ 8,267 $ 842 As of December 31, 2020, the Company had 550,795 of unvested stock awards that vest between January 1, 2021 and December 31, 2024. Based on the modifications of the stock awards in December 2020, the grant date fair value of the unvested awards was set to $12.80 per share. The future expense of the unvested awards by year is as follows (in thousands): 2021 $ 3,449 2022 2,022 2023 1,688 2024 951 Total $ 8,110

Redeemable Common Stock

Redeemable Common Stock	12 Months Ended
	Dec. 31, 2020
Temporary Equity Disclosure [Abstract]
Redeemable Common Stock	19. Redeemable Common Stock The activity of redeemable common stock classified as temporary equity, consists of issuances of new common stock, purchases of common stock and collection on outstanding stock subscription notes receivable. Also included in the activity are compensatory transactions wherein the majority shareholder sold shares to other shareholders at below fair value, thereby causing those shares to be subject to ASC Topic 718. On December 22, 2020, the Company’s shareholders approved a Fourth Amendment to the Shareholders Buy-Sell The activity of redeemable common stock for the years ended December 31, 2019 and 2020 is as follows (in thousands, except number of shares): Redeemable Common Stock Shares Amount Balance as of December 31, 2018 4,942,017 23,343 Issuances of new common stock 15,783 97 Purchases of common stock (268,745 ) (1,860 ) Controlling shareholder - net sales and purchases (42,893 ) (200 ) Collection on stock subscription notes receivable — 212 Measuring date adjustment to current fair value — 15,026 Balance as of December 31, 2019 4,646,162 36,618 Issuances of new common stock 57,230 499 Purchases of common stock (713,015 ) (9,017 ) Controlling shareholder - net sales and purchases 1,681 15 Measuring date adjustment to current fair value — 18,635 Movement to permanent equity (3,992,058 ) (46,750 ) Balance as of December 31, 2020 — —

Capital Leases

Capital Leases	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Capital Leases of Lessee [Abstract]
Capital Leases	16. Capital Leases On September 30, 2020, the Company converted operating leases for equipment and vehicles to capital leases and recorded the associated equipment purchases and capital lease liability, current and non-current. Future minimum commitments under non-cancelable 2021 $ 1,379 2022 5,088 2023 3,847 2024 1,654 2025 653 Total minimum lease payments $ 12,621 Less: amount representing interest (1,272 ) Present value of total net minimum lease payments $ 11,349 Less: current portion of net minimum lease payments (4,625 ) Long-term portion of net minimum lease payments $ 6,724 The above table is exclusive of the $2.1 million bargain purchase price million total liability to capital leases as presented on the consolidat e	20. Capital Leases On December 31, 2019, the company financed certain IT related and other equipment under capital lease agreements and certain IT related and other equipment and vehicles under operating lease agreements. The capital lease agreement requires 48 monthly payments, totaling $15,562 per month. The interest rate necessary to calculate the present value was an incremental borrowing rate of 3.8%, which is the rate on the revolving line of credit as of December 31, 2019. On September 30, 2020, the Company converted the remaining operating leases for equipment and vehicles to capital leases and recorded the associated equipment purchases and capital lease liability, current and non-current. Future minimum commitments under non-cancelable 2021 $ 3,916 2022 3,583 2023 2,341 2024 307 2025 — Total minimum lease payments 10,147 Less: amount representing interest (922 ) Present value of total net minimum lease payments 9,225 Less: current portion of net minimum lease payments (3,495 ) Long-term portion of net minimum lease payments $ 5,730 The above table is exclusive of the $1.9 million bargain purchase price associated with the $11.0 million total liability to capital leases as presented on the combined balance sheet.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17. Commitments and Contingencies Operating leases The Company leases office space, equipment a n Future minimum lease payments for the remainder of 2021 and for the succeeding years is as follows (in thousands): 2021 $ 1,471 2022 5,817 2023 4,613 2024 4,165 2025 3,661 Thereafter 9,378 Total $ 29,105	21. Commitments and Contingencies Operating leases The Company leases office space, equipment and vehicles. The Company financed vehicles, certain IT and other equipment under the terms of three primary master lease agreements accounted for as operating leases until September 30, 2020, when the Company converted the equipment and vehicles to capital lease as referenced in Note 21. Rent, vehicle and equipment lease expense for the years ended December 31, 2019 and 2020, was $7.4 million and $7.3 million, respectively. Aggregate actual and future minimum lease payments of the remaining operating leases for equipment and rent are as follows for the years ending December 31: 2021 $ 5,380 2022 5,000 2023 3,838 2024 3,330 2025 2,844 Thereafter 5,975 Total $ 26,367

Other

Other	12 Months Ended
	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Other	22. Other The Company is subject to legal proceedings and claims which arise in the ordinary course of business. In the opinion of management, the ultimate outcome of these matters will not be material to the Company’s combined financial position, results of operations or cash flows.

Subsequent Events

Subsequent Events	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	18. Subsequent Events On October 1, 2021, the Company completed the acquisition of assets and operations of Triangle Site Design located in Raleigh, North Carolina. In connection with the acquisition, the Company issued 65,428 shares of common stock to the seller. On October 8, 2021, the Company completed the acquisition of assets and operations of PCD Engineering, Inc. located in Denver, Colorado. In connection with the acquisition, the Company issued 36,444 shares of common stock to the seller. On October 15, 2021, the Company completed the acquisition of assets and operations of BTM Engineering located in Louisville, Kentucky. The Company did not issue shares of common stock to the seller. Given the short period of time between these acquisition dates and the issuance of this quarterly report on Form 10-Q, On November 10, 2021, the Company’s Board of Directors adopted the 2021 Executive Officers Short Term Incentive Plan and the 2021 Executive Officers Long Term Incentive Plan (“21LTIP”). Under the terms of the 21LTIP, performance stock units in the amount of 260,842 were issued to Gary Bowman, Bruce Labovitz, Michael Bruen and Robert Hickey in the aggregate. On December 15, 2021, the Company completed the acquisition of assets and operations of Kibart, Inc. located in Towson, Maryland. In connection with the acquisition, the Company issued 38,547 shares of common stock to the seller. On December 23, 2021, the Company completed the acquisition of assets and operations of 1519 Surveying PLLC located in Waco, Texas. In connection with the acquisition, the Company issued 50,559 shares of common stock to the seller. On December 31, 2021, the Company completed the acquisition of assets and operations of Terra Associates located in Houston, Texas. In connection with the acquisition, the Company issued 49,875 shares of common stock to the seller. From October 1, 2021 through December 31, 2021, the Company issued 40,160 shares under the Omnibus Equity Incentive Program and 13,962 shares under the Employee Stock Purchase Program.	23. Subsequent Events The Company has evaluated subsequent events through February 24, 2021, the date that the financial statements were issued. On January 4, 2021, the Company completed the acquisition of assets and operations of KTA Group, located in Herndon, Virginia. In connection with the acquisition, the Company issued 53,159 shares of common stock to the sellers. On April 30, 2021, the Company’s board of directors approved a forward 29.5-to-1 stock split of all common stock outstanding. The accompanying financial statements and related notes and schedules to the financial statements give retroactive effect to the stock split for all periods and as of all dates presented.

Additional Disclosures

Additional Disclosures	12 Months Ended
	Dec. 31, 2020
Additional Disclosures [Abstract]
Additional Disclosures	24. Additional Disclosures COVID-19 It is not possible at this time to estimate the full impact that COVID-19 COVID-19 COVID-19 COVID-19 COVID-19 shelter-in-place re-designation non-essential COVID-19

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Emerging Growth Company	Emerging Growth Company Section 102(b)(1) of the Jumpstart Our Business Startups Act (“JOBS Act”) exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging	Emerging Growth Company Section 102(b)(1) of the Jumpstart Our Business Startups Act (“JOBS Act”) exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging
Adoption of new accounting standard		Adoption of new accounting standard In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, 2014-09
Revenue Recognition	Revenue Recognition Accounting Standards Update (“ASU”) No. 2014-09, The Company generally recognizes revenue over time as control transfers to a customer based upon the extent of progress towards satisfaction of the performance obligation. For services delivered under fixed price contracts, the Company uses the ratio of actual costs incurred to total estimated costs at completion (an input method) as a reasonable measure of progress towards the satisfaction of a performance in order to estimate the portion of revenue earned. A contract containing a mix of hourly and fixed fee assignments may be characterized as one lump sum contract for purposes of ASC Topic 606. As such, a contract must contain hourly billed components exclusively to qualify for the as-billed	Revenue Recognition As discussed in Note 1, the Company provides a variety of engineering and related professional services to customers located throughout the United States. The Company enters into agreements with clients that create enforceable rights and obligations and for which it is probable that the Company will collect the consideration to which it will be entitled as services transfer to the customer. It is customary practice for the Company to have written agreements with its customers and revenue on oral or implied arrangements is generally not recognized. The Company recognizes revenue based on the consideration specified in the applicable agreement. Excluded from the transaction price are amounts collected on behalf of third parties for sales and similar taxes. Long-term contracts typically contain billing terms that provide for invoicing once a month and payment on a net 30-day As a professional services engineering firm, the Company generally recognizes revenue over time as control transfers to a customer based upon the extent of progress towards satisfaction of the performance obligation. For services delivered under fixed price contracts, the Company uses the ratio of actual costs incurred to total estimated costs since costs incurred (an input method) represent a reasonable measure of progress towards the satisfaction of a performance in order to estimate the portion of revenue earned. This method faithfully depicts the transfer of value to the customer when the Company is satisfying a performance obligation that entails a number of interrelated tasks or activities for a combined output that requires the Company to coordinate the work of employees and sub-consultants. catch-up When a performance obligation is billed using a time-and-material In certain situations, it is possible that two or more contracts should be combined and accounted for as a single contract, or a single contract should be accounted for as multiple performance obligations. This requires significant judgment and could impact the amount and timing of revenue recognition. Such determinations are made using management’s best estimate and knowledge of contracts and related performance obligations. The Company’s contracts may contain variable consideration in the form of unpriced or pending change orders or claims that either increase or decrease the contract price. Variable consideration is generally estimated using the expected value method but may from time to time be estimated using the most likely amount method depending on the circumstance. Estimated amounts are included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur or when the uncertainty associated with the variable consideration is resolved. Estimates of variable consideration are based upon historical experience and known trends. The Company recognizes claims against vendors, sub-consultants, Contract related assets and liabilities are classified as current assets and current liabilities. Significant balance sheet accounts related to the revenue cycle are as follows: Accounts receivables, net: Accounts receivable, net (contract receivables) includes amounts billed under the contract terms. The amounts are stated at their net realizable value. The Company maintains an allowance for doubtful accounts to provide for the estimated number of receivables that will not be collected. The Company considers several factors in its estimate of the allowance, including knowledge of a client’s financial condition, its historical collection experience, and other factors relevant to assessing the collectability of such receivables. Contract Assets: Contract Assets are recorded when progress to completion revenue earned on contracts exceeds amounts actually billed under the contract. It may also include contract retainages that can be billed once contract stipulations are satisfied. Contract Liabilities: Contract Liabilities are recorded when amounts actually billed under a contract exceeds the progress to completion revenue earned under the contract.
Contract Cost Assets		Contract Cost Assets Contract acquisition costs are comprised of costs to obtain and fulfill contracts. These costs, such as pre-contract
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires 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 financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could vary from the estimates and assumptions that were used.	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires 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 financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could vary from the estimates and assumptions that were used.
Cash and Cash Equivalent		Cash and Cash Equivalent The Company considers cash on deposit and all highly liquid investments with original maturities of three months or less when purchased to be cash and cash equivalents. Cash consists primarily of cash in accounts held at a financial institution. Certain of these accounts are designated as zero balance accounts wherein the balance is swept out nightly to reduce the Company’s line of credit balance, if any. Under the terms of the Company’s Credit Agreement, the Company’s primary lender may make advances to prevent or cover an overdraft on any of the Company’s accounts. The lender may make such advances even if the advances cause the outstanding balance to exceed the credit limit under the Credit Agreement. On the accompanying combined balance sheets at December 31, 2019 and 2020, the Company has included $1.7 million and $2.2 million, respectively, of payments in excess of cash on hand in accounts payable and accrued expenses. The total amount of such checks did not exceed the availability under the Company’s line of credit as of December 31, 2019 and December 31, 2020.
Concentration of Credit Risk and other Concentrations	Concentration of Credit Risk and other Concentrations The Company’s financial instruments that are exposed to concentrations of credit risk consist of cash and accounts receivable. Cash balances at various times during the year may exceed the amount insured by the Federal Deposit Insurance Corporation. The Company’s cash deposits are held in institutions whose credit ratings are monitored by management, and the Company has not incurred any losses related to such deposits. The Company is subject to a concentration of credit risk with respect to outstanding accounts receivable. However, the Company believes no such concentration existed during the nine months ended September 30, 2021, or the year ended December 31, 2020. The Company’s customers are located throughout the United States. Although the Company generally grants credit without collateral, management believes that its contract acceptance, billing, and collection policies are adequate to minimize material credit risk. Also, for non-governmental non-payment.	Concentration of Credit Risk and other Concentrations The Company’s financial instruments that are exposed to concentrations of credit risk consist of cash and accounts receivable. Cash balances at various times during the year may exceed the amount insured by the Federal Deposit Insurance Corporation. The Company’s cash deposits are held in institutions whose credit ratings are monitored by management, and the Company has not incurred any losses related to such deposits. The Company is subject to a concentration of credit risk with respect to outstanding accounts receivable, however the Company believes no such concentration existed during the years ended December 31, 2019 and 2020. The Company’s customers are located throughout the United States. Although the Company generally grants credit without collateral, management believes that its contract acceptance, billing, and collection policies are adequate to minimize material credit risk. Also, for non-governmental non-payment.
Allowance for Doubtful Accounts		Allowance for Doubtful Accounts The Company records accounts receivable net of an allowance for doubtful accounts. The allowance is determined based upon management’s review of the estimated collectability of the specific accounts receivable, plus a general provision based upon the historical loss experience and existing economic conditions. The Company charges off uncollectible amounts against the allowance for doubtful accounts once management determines the amount, or a portion thereof, to be worthless. As of December 31, 2019, and 2020, the balance in the allowance for doubtful accounts was $0.9 million and $1.5 million, respectively. Activity in the allowance for doubtful accounts that accounts for the change in balance consisted of the following: December 31, December 31, Balance as of beginning of the year $ 883 $ 939 Provision for doubtful accounts 129 799 Write-offs of uncollectable accounts (73 ) (190 ) Balance as of the end of the year $ 939 $ 1,548
Property and Equipment		Property and Equipment Property and equipment are recorded at cost. Improvements and replacements of property and equipment are capitalized. Maintenance and repairs that do not improve or extend the lives of property and equipment are charged to expense as incurred. Upon the sale or retirement of property and equipment, the cost and related accumulated depreciation are removed from the respective accounts and any gain or loss is reported in the combined statements of operations. Depreciation is provided for using the straight-line method over the estimated useful lives as follows for the major classes of assets:​​​​​​​ Computer equipment 3 to 5 years Survey equipment 2 to 5 years Vehicles 5 years Furniture and fixtures 7 years Software 3 to 5 years Leasehold improvements the lesser of useful life or term of lease
Business Combinations		Business Combinations Business combinations are accounted for under the acquisition method of accounting, which requires recognition separately from goodwill, the assets acquired, and the liabilities assumed at their acquisition date fair values. While best estimates and assumptions are used to calculate the fair value assets acquired and liabilities assumed at the acquisition date as well as contingent consideration, when applicable, the estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, adjustments that are based on new information obtained about facts and circumstances that existed as of the acquisition date are recorded to the assets acquired and liabilities assumed with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recognized in the combined income statements.
Goodwill and Intangible Assets		Goodwill and Intangible Assets The purchase price of an acquired business is allocated to the tangible assets and separately identifiable intangible assets acquired, less liabilities assumed, based upon their respective fair values with any excess purchase price over such fair values being recorded as goodwill. Goodwill and intangible assets acquired in a business combination and determined to have indefinite useful life are not amortized, but instead are reviewed for impairment annually, or more frequently if impairment indicators arise. Intangible assets with estimable useful lives are amortized over such lives and reviewed for impairment if indicators are present. The Company performs its annual impairment test as of October 1 of each year. As its business is highly integrated and its components have similar economic characteristics, the Company has concluded it has one reporting unit at the combined entity level. The Company performs a Step 1 impairment analysis by comparing the fair value of the reporting unit to carrying amount. Management engaged a third-party valuation firm to assist with the determination of fair value for the years ended December 31, 2019 and 2020. The fair value of the reporting unit derives from multiple weighted valuation techniques. If the fair value of the reporting unit is less than its carrying amount, we conduct a Step 2 impairment analysis to determine the implied fair value of the reporting unit’s goodwill. An impairment loss is recognized for the difference of the reporting unit’s implied fair value of goodwill and its carrying amount. The Company performed an impairment analysis for the years ended December 31, 2019 and 2020 and concluded that the fair value of the reporting unit was in excess of its carrying amount, and as such, no impairment was required. Definite-lived intangibles include customer relationships, contract rights, and non-compete The Company is required to review long-lived assets and definite-lived intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Recoverability of assets held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered impaired, the impairment recognized is measured by the amount by which the carrying amount of the asset exceeds its fair value. We report assets to be disposed of at the lower of the carrying amount or fair value, less cost to sell. There were no event or changes in circumstances, for the years ended December 31, 2019 and 2020, that indicated impairment of any long-lived assets.
Deferred Offering Costs		Deferred Offering Costs Upon closing of the planned initial public offering (“IPO”), deferred offering costs, consisting of legal, accounting and other fees directly related to the IPO will net against the gross proceeds. As of December 31, 2020, the Company recorded $0.9 million of deferred offering costs that are included in other assets on the accompanying combined balance sheet.
Deferred Rent		Deferred Rent The Company recognizes rent expense on a straight-line basis over the term of each operating lease commencing on the date the Company takes possession of the leased premises. In addition, the Company records allowances such as free rent or improvement allowances as deferred rent in the combined balance sheets and amortizes the amount on a straight-line basis over the term of the related operating lease.
Long-term incentive compensation plan		Long-term incentive compensation plan The Company maintains a variable compensation plan and discretionary bonus program for employees and provides individualized long-term incentive plans to certain managers and executives. The variable compensation plan and discretionary bonus program includes cash awards and the long-term incentive plans include issuance of restricted stock grants. The Company periodically grants restricted stock awards to reward performance and incentivize retention.
Stock-based Compensation		Stock-based Compensation Shares originating from the granting of restricted stock bonus awards, stock options and the sale of stock to employees at prices below fair value are subject to Accounting Standards Codification Topic 718, Compensation – Stock Compensation non-cash On December 22, 2020 and December 31, 2020, the Company modified its stock-based compensation agreements resulting in a change in classification of the majority of these awards from liability to equity. The modification resulted in a final fair value liability measurement and non-cash non-cash For ASC Topic 718 stock-based awards classified as permanent equity, the Company generally recognizes non-cash
Non-recourse Notes Treated as Substantive Options		Non-recourse Certain stock subscription notes receivable of the Company are non-recourse. pre-paid, non-recourse
Redeemable Common Shares		Redeemable Common Shares Prior to December 22, 2020, the Company classified shares issued subject to Accounting Standards Codification 480 – Distinguishing Liabilities from Equity
Fair Value Measurements	Fair Value Measurements Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosures The codification establishes a three-level disclosure hierarchy to indicate the level of judgment used to estimate fair value measurements: Level 1: Level 2: Level 3: As of September 30, 2021 and December 31, 2020: • The carrying amount of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair value due to the relatively short duration of these instruments; • The carrying amounts of debt obligations approximate their fair values as the terms are comparable to terms currently offered by local financial institutions for arrangements with similar terms to industry peers with comparable credit characteristics. Accordingly, the debt obligations involve Level 2 fair value inputs; • As of December 31, 2020 the liability related to shares subject to repurchase is recognized at fair value using Level 3 inputs that were primarily determined based on the contractual settlement price as defined by the terms of the Company’s Shareholders’ Buy-Sell Stock Bonus Plan	Fair Value Measurements Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosures The codification establishes a three-level disclosure hierarchy to indicate the level of judgment used to estimate fair value measurements: Level 1: Quoted prices in active markets for identical assets or liabilities as of the reporting date; Level 2: Quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; and inputs other than quoted prices (such as interest rate and yield curves); Level 3: Uses inputs that are unobservable, supported by little or no market activity and reflect significant management judgment. As of December 31, 2019, and 2020: • The carrying amount of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair value due to the relatively short duration of these instruments • The carrying amounts of debt obligations approximate their fair values as the terms are comparable to terms currently offered by local financial institutions for arrangements with similar terms to industry peers with comparable credit characteristics. Accordingly, the debt obligations involve Level 2 fair value inputs. • The liability related to shares subject to repurchase is recognized at fair value using Level 3 inputs that were primarily determined based on the contractual settlement price as defined by the terms of the Company’s Shareholders’ Buy-Sell See Note 18 for further discussion.
Advertising Expense		Advertising Expense The Company expenses the cost of advertising as incurred. Advertising expense was $0.1 million and $0.1 million for the years ended December 31, 2019 and 2020, respectively.
Income Taxes	Income Taxes The Company recognizes deferred income tax assets or liabilities for expected future tax consequences of events recognized in the consolidated financial statements or tax returns. Under this method, deferred income tax assets or liabilities are determined based upon the difference between the financial statement and income tax bases of assets and liabilities using enacted tax rates expected to apply when the differences settle or become realized. Valuation allowances are provided when it is more likely than not that a deferred tax asset is not realizable or recoverable in the future. The Company recognizes the effect of a change in tax rates on deferred tax assets and liabilities in income in the period that includes the enactment date. The Company’s effective tax rate for the nine months ended September 30, 2021 and 2020 was (18.6%) and 37.03%. The Company assesses uncertain tax positions to determine whether the position will more likely than not be sustained upon examination by the Internal Revenue Service (IRS) or other taxing authorities. If the Company cannot reach a more-likely-than-not The Company files income tax returns in the U.S. federal jurisdiction and certain states in which it operates. Based on the timing of the filing of certain tax returns, the Company’s federal income tax returns for tax years 2017 and after remain subject to examination by the U.S. Internal Revenue Service. The statute of limitations on the Company’s state income tax returns generally conforms to the federal three-year statute of limitations.	Income Taxes On January 1, 2018, the Company changed it election from an S-corporation C-corporation. The Company recognizes deferred income tax assets or liabilities for expected future tax consequences of events recognized in the combined financial statements or tax returns. Under this method, deferred income tax assets or liabilities are determined based upon the difference between the financial statement and income tax bases of assets and liabilities using enacted tax rates expected to apply when the differences settle or become realized. Valuation allowances are provided when it is more likely than not that a deferred tax asset is not realizable or recoverable in the future. The Company recognizes the effect of a change in tax rates on deferred tax assets and liabilities in income in the period that includes the enactment date. The Company assesses uncertain tax positions to determine whether the position will more likely than not be sustained upon examination by the Internal Revenue Service (IRS) or other taxing authorities. If the Company cannot reach a more-likely-than-not
Segments	Segments The Company operates in one segment based upon the financial information used by its chief operating decision maker in evaluating the financial performance of its business and allocating resources. The single segment represents the Company’s core business of providing engineering and related professional services to its customers.	Segments The Company operates in one segment based upon the financial information used by its chief operating decision maker in evaluating the financial performance of its business and allocating resources. The single segment represents the Company’s core business of providing engineering and related professional services to its customers.
Recently Issued Accounting Guidance	Recently Issued Accounting Guidance Accounting guidance not yet adopted Leases 2016-02, 2016-02”) right-of-use 2016-02 Financial Instruments—Credit Losses 2016-13, 2016-13 Goodwill 2017-04, 2017-04 2017-04	Recently Issued Accounting Guidance Accounting guidance not yet adopted Leases 2016-02, 2016-02”) right-of-use 2016-02 Financial Instruments – Credit Losses 2016-13, 2016-13 Goodwill 2017-04, 2017-04 2017-04

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Allowance for Doubtful Accounts	Activity in the allowance for doubtful accounts that accounts for the change in balance consisted of the following: December 31, December 31, Balance as of beginning of the year $ 883 $ 939 Provision for doubtful accounts 129 799 Write-offs of uncollectable accounts (73 ) (190 ) Balance as of the end of the year $ 939 $ 1,548
Summary of Property plant and equipment useful lives	Depreciation is provided for using the straight-line method over the estimated useful lives as follows for the major classes of assets: Computer equipment 3 to 5 years Survey equipment 2 to 5 years Vehicles 5 years Furniture and fixtures 7 years Software 3 to 5 years Leasehold improvements the lesser of useful life or term of lease

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Summary of Reconciliation of Net Income and Weighted Average Shares Outstanding for Calculation of Basic and Diluted Earnings per Share	The following table represents a reconciliation of the net income and weighted average shares outstanding for the calculation of basic and diluted earnings per share for the three and nine months ended September 30, 2021 and 2020 (in thousands, except share data): For the Three Months Ended For the Nine Months Ended 2021 2020 2021 2020 Numerator Net income (loss) $ 357 $ (1,248 ) $ 899 $ 794 Earnings allocated to non-vested 71 — 165 41 Subtotal $ 286 $ (1,248 ) $ 734 $ 753 Denominator Weighted average common shares outstanding 8,920,505 5,567,523 7,003,462 5,569,177 Effect of dilutive nominal options — — — 4,396 Effect of dilutive contingently earned shares 14,769 — 4,978 31,231 Dilutive average shares outstanding 8,935,274 5,567,523 7,008,440 5,604,804 Basic earnings (loss) per share $ 0.03 $ (0.22 ) $ 0.10 $ 0.14 Dilutive earnings (loss) per share $ 0.03 $ (0.22 ) $ 0.10 $ 0.13	The following table represents a reconciliation of the net income and weighted average shares outstanding for the calculation of basic and diluted earnings per share for the years ending December 31, 2019, and 2020: December 31, December 31, Numerator Net income 1,526 990 Deemed dividend 8 — Earnings allocated to non-vested 38 55 Subtotal $ 1,480 $ 935 Denominator Weighted average common shares outstanding 5,770,170 5,399,356 Effect of dilutive nominal options 4,809 5,162 Effect of dilutive contingently earned shares 30,857 7,700 Dilutive average shares outstanding 5,805,836 5,412,218 Basic earnings per share $ 0.26 $ 0.17 Dilutive earnings per share $ 0.25 $ 0.17

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Summary of Preliminary Calculations of the Fair Values of Assets Acquired and Liabilities Assumed	The following summarizes the preliminary calculations of the fair values of MDA assets acquired and liabilities assumed as of the acquisition date (in thousands): Total Purchase Price $ 3,967 Purchase Price Allocation: Accounts Receivable 1,033 Contract assets 410 Property and equipment, net 39 Intangible Assets 990 Other assets 34 Accounts payable and other current liabilities (70) Contract liabilities (230) Total identifiable assets $ 2,206 Goodwill 1,761 Net assets acquired $ 3,967

Contracts in Progress (Tables)

Contracts in Progress (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Summary of Costs and Estimated Earnings on Contracts	The following table reflects the calculation of the net balance of contract assets and contract liabilities. Costs and estimated earnings on contracts in progress consist of the following (in thousands): September 30, 2021 December 31, 2020 Costs incurred on uncompleted contracts $ 148,335 $ 113,856 Estimated contract earnings in excess of costs 198,528 151,423 Estimated contract earnings to date 346,863 265,279 Less: billed to date (340,753 ) (260,142 ) Net contract assets $ 6,110 $ 5,137	The following table reflects the calculation of the net balance of contract assets and contract liabilities. Costs and estimated earnings on contracts in progress consist of the following (in thousands): December 31, December 31, Costs incurred on uncompleted contracts $ 112,417 $ 113,856 Estimated contract earnings in excess of costs 160,242 151,423 Estimated contract earnings to date 272,659 265,279 Less: billed to date (270,439 ) (260,142 ) Net contract assets $ 2,220 $ 5,137

Notes Receivable (Tables)

Notes Receivable (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Receivables [Abstract]
Summary of Notes Receivable	The Company has unsecured notes receivable from related parties, certain non-executive September 30, 2021 December 31, 2020 Officers, employees and affiliated entities—Interest accrues annually at rates ranging from 3.25%—5.5%. The notes receivable mature through December 2021 $ 2,393 $ 2,479 Unrelated third party—Currently no interest is being accrued on this note. The note receivable matures in December 2023 903 903 Total: 3,296 3,382 Less: current portion Officers, employees and affiliates (1,120 ) (1,182 ) Unrelated third party — — Noncurrent portion $ 2,176 $ 2,200	The following is a summary of these notes receivable (in thousands): December 31, December 31, Officers, employees and affiliated entities - Interest accrues annually at rates ma December 2021 $ 8,995 $ 2,479 Unrelated third party - Interest accrues annually at an interest rate of December 2023 904 903 Total 9,899 3,382 Less: current portion Officers, employees and affiliates (525 ) (1,182 ) Unrelated third party (904 ) (— ) Noncurrent portion $ 8,470 $ 2,200

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment for Fixed Assets	Property and equipment for fixed assets are as follows (in thousands): September 30, 2021 December 31, 2020 Computer equipment $ 1,260 $ 1,276 Survey equipment 4,444 4,444 Vehicles 460 463 Furniture and fixtures 1,661 1,638 Leasehold improvements 6,727 5,887 Software 283 283 Fixed assets pending lease financing 1 351 146 Total: 15,186 14,137 Less: accumulated depreciation (10,460 ) (9,912 ) Property and Equipment, net of capital leased assets $ 4,726 $ 4,225 1 assets acquired which will be re-financed	Property and equipment for fixed assets are as follows (in thousands): December 31, December 31, Computer equipment 1,427 1,276 Survey equipment 4,444 4,444 Vehicles 473 463 Furniture and fixtures 1,628 1,638 Leasehold improvements 4,635 5,887 Software 283 283 Fixed asset inventory 488 146 13,378 14,137 Less: accumulated depreciation (9,330 ) (9,912 ) Property and Equipment, net 4,048 4,225
Summary of Property and Equipment for Capital Leased Assets	Property and equipment for capital leased assets are as follows (in thousands): September 30, 2021 December 31, 2020 Equipment $ 13,393 $ 8,590 Vehicles 4,516 3,825 Total: 17,909 12,415 Less: accumulated amortization on leased assets (4,771 ) (1,283 ) Capital Leased Assets, net $ 13,138 $ 11,132	Property and equipment for capital leased assets are as follows (in thousands): December 31, December 31, Equipment $ 722 $ 8,590 Vehicles — 3,825 722 12,415 Less: accumulated amortization on leased assets — (1,283 ) Capital Leased Assets, net $ 722 $ 11,132

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill Resulting From Business Acquisitions	The following is a summary of goodwill resulting from business acquisitions held by the Company at September 30, 2021 and December 31, 2020 (in thousands): Goodwill Balance as of December 31, 2020 $ 9,179 Acquisition—KTA Group 2,544 Acquisition—McFarland-Dyer & Associates 1,761 Balance as of September 30, 2021 $ 13,484	The following is a summary of goodwill resulting from business acquisitions held by the Company at December 31, 2019 and 2020 (in thousands): December 31, December 31, Goodwill $ 9,179 $ 9,179

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Intangible Assets [Abstract]
Summary of Total Intangible Assets	Total intangible assets consisted of the following at September 30, 2021 and December 31, 2020 (in thousands): September 30, 2021 December 31, 2020 Gross Accumulated Net Gross Accumulated Net Customer relationships $ 2,192 $ (534 ) $ 1,658 $ 809 $ (382 ) $ 427 Contract rights 488 (185 ) 303 150 (150 ) — Leasehold 160 (13 ) 147 — — — Non-complete 137 (137 ) — 137 (114 ) 23 Domain name 281 — 281 281 — 281 Licensing rights 400 — 400 400 — 400 Total $ 3,658 $ (869 ) $ 2,789 $ 1,777 $ (646 ) $ 1,131	Total intangible assets consisted of the following at December 31, 2019 and December 31, 2020 (in thousands): December 31, 2019 December 31, 2020 Gross Accumulated Net Gross Accumulated Net Customer relationships $ 809 $ (225 ) $ 584 $ 809 $ (382 ) $ 427 Contract rights 150 (112 ) 38 150 (150 ) — Non-complete 137 (68 ) 69 137 (114 ) 23 Domain name — — — 281 — 281 Licensing rights — — — 400 — 400 Total $ 1,096 $ (405 ) $ 691 $ 1,777 $ (646 ) $ 1,131
Summary of Weighted Average Useful Lives of Intangible Assets by Asset Class Used for Straight-line Expense Purposes	The following table summarizes the weighted average useful lives of intangible assets by asset class used for straight-line expense purposes: September 30, December 31, Customer relationships 12.8 5.0 Contract rights 2.4 2.0 Leasehold 9.2 — Non-compete 3.0 3.0	The following table summarizes the weighted average useful lives of intangible assets by asset class used for straight-line expense purposes: December 31, December 31, Customer relationships 4.98 4.98 Contract rights 2.0 2.0 Non-compete 3.0 3.0
Summary of Future amortization	Future amortization for the remainder of 2021 and for the succeeding years is as follows (in thousands): 2021 $ 100 2022 397 2023 336 2024 102 2025 102 Thereafter 1,071 Total $ 2,108	Actual and future amortization is as follows for the years ending December 31 (in thousands): 2021 $ 181 2022 158 2023 111 Total $ 450

Notes Payable (Tables)

Notes Payable (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Debt Instruments [Abstract]
Schedule of Notes Payable	Notes payable consist of the following (in thousands): September 30, December 31, Related parties: Shareholders—Interest accrues annually at rates ranging from 0.00%—6.25%. The notes payable mature on various dates through October 2025. $ 4,767 $ 2,202 Unrelated third parties: Note payable for purchase of intangible asset 150 — Fixed line notes payable—see note 11 1,682 2,219 Total 6,599 4,421 Less: current portion (2,222 ) (1,592 ) Noncurrent portion $ 4,377 $ 2,829	Notes payable consist of the following (in thousands): December 31, December 31, Related parties: BCG Chantilly, LLC - Interest accrues annually at 12.00%; payable in varying semi-annual installments of principal and interest through maturity in October 2021. This note was paid in full September 30, 2020. 225 — Shareholders - Interest accrues annually at rates ranging from 0.00% - 6.25%. The notes payable mature on various dates through October 2025. 2,085 2,202 Unrelated third parties: Settlement notes payable - see below 625 — Fixed line notes payable - see note 11 725 2,219 Total 3,660 4,421 Less: current portion 1,744 1,592 Noncurrent portion $ 1,916 $ 2,829
Schedule of Future Principal Payments on Notes Payable	Future principal payments on notes payable for remainder of 2021 and succeeding years are as follows (in thousands): 2021 $ 744 2022 2,276 2023 1,932 2024 1,286 2025 361 Total $ 6,599	Actual and estimated future principal payments on notes payable are as follows for the years ending December 31 (in thousands): 2021 $ 1,592 2022 1,263 2023 886 2024 464 2025 216 Total $ 4,421

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Summary of Provision for Income Taxes	The provision for income taxes consisted of the following (in thousands): December 31, December 31, Current expense: Federal $ 280 $ 1 State 326 662 Total 606 663 Deferred expense (benefit): Federal 468 404 State (36 ) (78 ) Total 432 326 Provision for income taxes $ 1,038 $ 989
Schedule of Components of Deferred Tax Assets and Deferred Tax Liabilities	The Company measures deferred tax assets and liabilities based on the difference between the financial statement and tax bases of assets and liabilities at the applicable tax rates. Components of the Company’s deferred tax asset and liability are as follows (in thousands): December 31, December 31, Deferred tax assets: Research and development credit carryover $ 275 $ 1,557 Deferred rent expense 1,002 1,073 Intangible asset amortization 78 23 1,355 2,653 Deferred tax liabilities: Fixed asset depreciation (375 ) (2,866 ) Accrual to cash adjustments (6,249 ) (5,398 ) Goodwill amortization (777 ) (861 ) (7,401 ) (9,125 ) Net deferred tax liabilities ($ 6,046 ) ($ 6,472 )
Schedule of Reconciliation of Income Tax Expense	Income tax expense differed from the amounts computed by applying the federal statutory income tax rate of 21% to pretax income due to the following adjustments (in thousands): December 31, 2019 December 31, 2020 Statutory Rate $ 528 $ 410 State income taxes, net of federal benefit 76 69 Effective rate differential for DCPC—S-corp 81 (59 ) State income tax rate change 83 77 Permanent differences 97 68 Stock repurchase liability 1,078 1,474 Valuation Allowance — 27 Change in tax status — 170 Other 53 42 Research & development credit (958 ) (1,289 ) Provision for income tax $ 1,038 $ 989

Stock Options (Tables)

Stock Options (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Summary of Assumptions Used to Value the Options Granted		The assumptions used to value the options granted include: December 31, December 31, Expected volatility 39.0 % 25.0 % Expected dividend yield 0.0 % 0.0 % Expected option term (in years) 2.5 5.0 Risk-free interest rate 2.6 % 2.5 %
Summary of Status of Stock Options Exercised, Including Substantive Options and Information about Options Outstanding and Exercisable	A summary of the status of stock options exercised, including the substantive options discussed in Note 3, is as follows: Number of shares Weighted Average Exercise Price Outstanding at January 1, 2021 53,277 $ 5.87 Granted — — Exercised (33,276 ) 5.64 Expired or cancelled — — Outstanding at September 30, 2021 20,001 $ 6.25 The following summarizes information about options outstanding and exercisable at January 1, 2021 and September 30, 2021: Options Outstanding and Exercisable Exercise Price Total Outstanding Weighted Average Remaining Life (Years) Weighted Average Exercise Price Total Exercisable January 1, 2021 $ 6.37 53,277 4.5 $ 5.87 53,277 September 30, 2021 $ 6.57 20,001 5.0 $ 6.25 20,001	A summary of the status of stock options granted, including the substantive options discussed in Note 3, is as follows: Number Weighted Outstanding at January 1, 2019 2,950 0.34 Granted 111,982 3.15 Exercised (55,578 ) 0.58 Expired or cancelled (2,950 ) 0.34 Outstanding at December 31, 2019 56,404 $ 5.68 Granted 7,434 7.34 Exercised (10,561 ) 5.92 Expired or cancelled — — Outstanding at December 31, 2020 53,277 $ 5.87 The following summarizes information about options outstanding and exercisable at December 31, 2019 and December 31, 2020: Options Outstanding and Exercisable Exercise Total Weighted Weighted Total December 31, 2019 $ 6.00 56,404 4.5 $ 5.68 56,404 December 31, 2020 $ 6.37 53,277 4.5 $ 5.87 53,277

Stock Bonus Plan (Tables)

Stock Bonus Plan (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Summary of Activity of Restricted Shares Subject to Forfeiture	The following table summarizes the activity of restricted shares subject to forfeiture: Number of shares Weighted Average Grant Price Outstanding at January 1, 2021 702,926 $ 12.80 Granted 1,603,423 13.95 Vested (96,527 ) 12.80 Cancelled (108 ) 13.02 Outstanding at September 30, 2021 2,209,714 $ 13.63	The following table summarizes the activity of restricted shares subject to forfeiture: Number of Weighted Outstanding at January 1, 2019 188,948 5.48 Granted 47,141 5.91 Vested (77,438 ) 5.52 Cancelled (2,242 ) 5.49 Outstanding at December 31, 2019 156,409 5.59 Granted 657,673 11.00 Vested (108,206 ) 6.49 Cancelled (2,950 ) 5.49 Outstanding at December 31, 2020 1 702,926 10.51 Outstanding at December 31, 2020, as modified 2 702,926 12.80 1 Weighted average grant price at December 31, 2020 represents the grant date fair value of Stock Awards as originally issued. 2 Weighted average grant price at December 31, 2020, as modified, represents the as adjusted fair value of the outstanding Stock Awards on the date of modification in connection with the settlement of the liability to common shares subject to repurchase.
Summary of Change in Liability to Common Shares Subject to Repurchase and Associated Non-cash Compensation Expense	The following table represents the change in the liability to common shares subject to repurchase and the associated non-cash September 30, 2021 December 31, 2020 Beginning Balance $ 842 $ 8,267 Non-cash 41 2,712 Non-cash 2 2,457 Other stock activity, net 516 (786 ) Reclassification upon modification (1,394 ) (11,808 ) Ending balance $ 7 $ 842	The following table represents the change in the liability to common shares subject to repurchase and the associated non-cash December 31, December 31, 2019 2020 Beginning balance $ 4,464 $ 8,267 Non-cash 1,468 2,712 Non-cash 2,335 2,457 Other stock activity, net — (786 ) Reclassification upon modification — (11,808 ) Ending balance $ 8,267 $ 842
Summary of Future Expense of Unvested Awards	The future expense of the unvested awards for the remainder of 2021 and succeeding years is as follows (in thousands): 2021 $ 2,527 2022 8,652 2023 7,378 2024 4,545 Thereafter 1,547 Total $ 24,649	The future expense of the unvested awards by year is as follows (in thousands): 2021 $ 3,449 2022 2,022 2023 1,688 2024 951 Total $ 8,110

Redeemable Common Stock (Tables

Redeemable Common Stock (Tables)	12 Months Ended
	Dec. 31, 2020
Temporary Equity Disclosure [Abstract]
Summary of the Activity of Redeemable Common Stock	The activity of redeemable common stock for the years ended December 31, 2019 and 2020 is as follows (in thousands, except number of shares): Redeemable Common Stock Shares Amount Balance as of December 31, 2018 4,942,017 23,343 Issuances of new common stock 15,783 97 Purchases of common stock (268,745 ) (1,860 ) Controlling shareholder - net sales and purchases (42,893 ) (200 ) Collection on stock subscription notes receivable — 212 Measuring date adjustment to current fair value — 15,026 Balance as of December 31, 2019 4,646,162 36,618 Issuances of new common stock 57,230 499 Purchases of common stock (713,015 ) (9,017 ) Controlling shareholder - net sales and purchases 1,681 15 Measuring date adjustment to current fair value — 18,635 Movement to permanent equity (3,992,058 ) (46,750 ) Balance as of December 31, 2020 — —

Capital Leases (Tables)

Capital Leases (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Capital Leases of Lessee [Abstract]
Schedule of Future Minimum Commitments Under Non-cancelable Capital Leases	Future minimum commitments under non-cancelable 2021 $ 1,379 2022 5,088 2023 3,847 2024 1,654 2025 653 Total minimum lease payments $ 12,621 Less: amount representing interest (1,272 ) Present value of total net minimum lease payments $ 11,349 Less: current portion of net minimum lease payments (4,625 ) Long-term portion of net minimum lease payments $ 6,724	Future minimum commitments under non-cancelable 2021 $ 3,916 2022 3,583 2023 2,341 2024 307 2025 — Total minimum lease payments 10,147 Less: amount representing interest (922 ) Present value of total net minimum lease payments 9,225 Less: current portion of net minimum lease payments (3,495 ) Long-term portion of net minimum lease payments $ 5,730

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Lessee, Operating Lease, Liability, Payment, Due, Rolling Maturity [Abstract]
Summary of Future Minimum Lease Payments	Future minimum lease payments for the remainder of 2021 and for the succeeding years is as follows (in thousands): 2021 $ 1,471 2022 5,817 2023 4,613 2024 4,165 2025 3,661 Thereafter 9,378 Total $ 29,105	Aggregate actual and future minimum lease payments of the remaining operating leases for equipment and rent are as follows for the years ending December 31: 2021 $ 5,380 2022 5,000 2023 3,838 2024 3,330 2025 2,844 Thereafter 5,975 Total $ 26,367

Nature of Business and Basis _2

Nature of Business and Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Thousands

Jun. 08, 2021USD ($)shares

Jun. 04, 2021USD ($)$ / sharesshares

May 11, 2021USD ($)$ / sharesshares

Dec. 22, 2020

Mar. 28, 1956

Sep. 30, 2019

Aug. 31, 2014

Oct. 31, 2002

Sep. 30, 2021USD ($)

Sep. 30, 2020USD ($)

Dec. 31, 2020USD ($)Number

Dec. 31, 2019USD ($)

Nature Of Business And Basis Of Presentation [Line Items]

Proceeds from issuance of common stock

$ 297

$ 45

$ 63

$ 130

Number of states based on description | Number

2

Bowman North Carolina Ltd Previously Known As He Wilson Liquidations Inc

Nature Of Business And Basis Of Presentation [Line Items]

Entity incorporation, Date of incorporation

Dec. 22, 2020

Business acquisition, Effective date of acquisition

Dec. 22, 2020

DCPC And NCPC [Member]

Nature Of Business And Basis Of Presentation [Line Items]

Business acquisition, Effective date of acquisition

Dec. 31, 2020

HE Wilson Liquidations Inc [Member]

Nature Of Business And Basis Of Presentation [Line Items]

Entity incorporation, Date of incorporation

Mar. 28, 1956

Bowman Consulting DCPC [Member]

Nature Of Business And Basis Of Presentation [Line Items]

Entity incorporation, Date of incorporation

Aug. 1, 2014

Bowman Consulting NCPC [Member]

Nature Of Business And Basis Of Presentation [Line Items]

Entity incorporation, Date of incorporation

Sep. 1, 2019

Omland Engineering Land Survey And Landscape Architecture Associates PC [Member]

Nature Of Business And Basis Of Presentation [Line Items]

Entity incorporation, Date of incorporation

Oct. 1, 2002

Initial Public Offering

Nature Of Business And Basis Of Presentation [Line Items]

Number of shares issued and sold | shares

115,925

3,690,000

Shares price per share | $ / shares

$ 14

$ 14

Net proceeds from sale of common stock

$ 48,000

Proceeds from issuance of common stock

$ 1,600

Deferred offering costs reclassified into shareholder's equity

$ 2,300

Deferred offering costs capitalized

$ 900

Over-Allotment Option

Nature Of Business And Basis Of Presentation [Line Items]

Number of shares issued and sold | shares

3,805,925

Net proceeds from sale of common stock

$ 1,500

Proceeds from issuance of common stock

$ 53,300

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Details) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2021USD ($)segment	Sep. 30, 2020	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Accounting Policies [Line Items]
Revenue from contracts classified as lump sum	96.20%	95.50%		95.30%
Revenue from exclusively time and material contracts	3.80%	4.50%		4.70%
Remaining performance obligations	$ 114,600	$ 114,600		$ 81,300
Effective tax rate		(18.60%)	37.03%
Number of operating segment | segment		1		1
Allowance for doubtful debts on accounts payable current				$ 1,548	$ 939	$ 883
Deferred offering costs non current				900
Advertising expenses				$ 100	100
Minimum shareholding percentage necessary to determine the taxable limit				95.00%
Gain On Sale [Member]
Accounting Policies [Line Items]
Gain loss on sale and leaseback transactions				$ 100	100
Accounts Payable and Accrued Liabilities [Member]
Accounting Policies [Line Items]
Payments in excess of cash on hand				$ 2,200	$ 1,700

Significant Accounting Polici_5

Significant Accounting Policies - Additional Information (Details 1)	Sep. 30, 2021	Dec. 31, 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-10-01
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Remaining performance obligations expects to recognize	99.10%	67.00%
Remaining performance obligations, expected satisfaction period	12 months	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-10-01
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Remaining performance obligations expects to recognize	0.90%	33.00%
Remaining performance obligations, expected satisfaction period	0 years

Significant Accounting Polici_6

Significant Accounting Policies - Summary of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Balance as of beginning of the year	$ 939	$ 883
Provision for doubtful accounts	799	129
Write-offs of uncollectable accounts	(190)	(73)
Balance as of the end of the year	$ 1,548	$ 939

Significant Accounting Polici_7

Significant Accounting Policies - Summary of Property Plant and Equipment Useful Lives (Details)	12 Months Ended
	Dec. 31, 2020
Computer Equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Computer Equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Survey Equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	2 years
Survey Equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Vehicles
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Software | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Software | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Leasehold improvements	the lesser of useful life or term of lease

Earnings per Share - Additional

Earnings per Share - Additional Information (Details) - USD ($)	Aug. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Line Items]
Non-vested restricted shares		2,194,343	310,922	1,541,174	253,141	268,450	137,706
Substantive options shares		21,499	55,548	36,246	52,673	53,395	8,968
Undistributed earnings, Decrease due to stock redemption							$ 8,148
Redeemable Common Stock [Member]
Earnings Per Share [Line Items]
Stock redeemed or called during period, Shares	38,350

Earnings per Share - Summary of

Earnings per Share - Summary of Reconciliation of Net Income and Weighted Average Shares Outstanding for Calculation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net income (loss)	$ 357	$ (1,248)	$ 899	$ 794	$ 990	$ 1,526
Deemed dividend						8
Earnings allocated to non-vested shares	71		165	41	55	38
Subtotal	$ 286	$ (1,248)	$ 734	$ 753	$ 935	$ 1,480
Weighted average common shares outstanding	8,920,505	5,567,523	7,003,462	5,569,177	5,399,356	5,770,170
Effect of dilutive nominal options				4,396	5,162	4,809
Effect of dilutive contingently earned shares	14,769		4,978	31,231	7,700	30,857
Dilutive average shares outstanding	8,935,274	5,567,523	7,008,440	5,604,804	5,412,218	5,805,836
Basic	$ 0.03	$ (0.22)	$ 0.10	$ 0.14	$ 0.17	$ 0.26
Diluted	$ 0.03	$ (0.22)	$ 0.10	$ 0.13	$ 0.17	$ 0.25

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - USD ($)	Dec. 22, 2020	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Bowman Consulting DCPC [Member] | Mr Gary Bowman Chairman And Chief Executive Officer [Member]
Business Acquisition [Line Items]
Equity method investment, Ownership percentage						100.00%	100.00%
Bowman Consulting NCPC [Member] | Mr Gary Bowman Chairman And Chief Executive Officer [Member]
Business Acquisition [Line Items]
Equity method investment, Ownership percentage						90.00%	90.00%
Bowman Consulting NCPC [Member] | Shareholder [Member]
Business Acquisition [Line Items]
Equity method investment, Ownership percentage						5.00%	5.00%
Bowman Consulting NCPC [Member] | Mr Mike Bruen Chief Operating Officer [Member]
Business Acquisition [Line Items]
Equity method investment, Ownership percentage						5.00%	5.00%
Thirty Month Promissory Note [Member]
Business Acquisition [Line Items]
Debt instrument, Term			30 months
Debt instrument, Face amount			$ 300,000
Interest expense debt			$ 14,399
Share price			$ 8.10
Atherton Asset Acquisition [Member]
Business Acquisition [Line Items]
Asset acquisition, Effective date of acquisition			Jun. 30, 2018
Asset acquisition, Consideration transferred			$ 400,000
Asset acquisition, Consideration transferred, Contingent consideration			200,000
Asset acquisition, Consideration transferred, Transaction cost			$ 0
Atherton Asset Acquisition [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Asset acquisition, Equity interest issued or issuable, Number of shares			38,350
Asset acquisition, Share price			$ 7.15
Asset acquisition, Consideration transferred, Equity interest issued and issuable			$ 200,000
Asset acquisition, Put option rights per share associated with the equity interest issued			$ 8.47
Asset acquisition, Put option rights associated with the equity interest issued, Vesting period			12 months
Westland Asset Acquisition [Member]
Business Acquisition [Line Items]
Asset acquisition, Effective date of acquisition		Sep. 30, 2018
Asset acquisition, Consideration transferred		$ 700,000
Asset acquisition, Consideration transferred, Transaction cost		0
Payments to acquire productive assets		100,000
Westland Asset Acquisition [Member] | Accounts Payable And Accrued Liabilities Current [Member]
Business Acquisition [Line Items]
Percentage of the contingent consideration expected to be paid						100.00%	100.00%	100.00%
Westland Asset Acquisition [Member] | Contingent Consideration Based On Revenue Generated From Acquired Contracts [Member]
Business Acquisition [Line Items]
Asset acquisition, Consideration transferred, Contingent consideration		$ 300,000
Westland Asset Acquisition [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Asset acquisition, Equity interest issued or issuable, Number of shares		50,327
Asset acquisition, Share price		$ 5.49
Asset acquisition, Consideration transferred, Equity interest issued and issuable		$ 300,000
Customer Relationships | Atherton Asset Acquisition [Member]
Business Acquisition [Line Items]
Estimated useful life of intangibles			5 years
Asset acquisition, Recognized identifiable assets acquired, Finite lived intangibles			$ 100,000
Customer Relationships | Westland Asset Acquisition [Member]
Business Acquisition [Line Items]
Estimated useful life of intangibles		5 years
Asset acquisition, Recognized identifiable assets acquired, Finite lived intangibles		$ 400,000
Contract Rights | Atherton Asset Acquisition [Member]
Business Acquisition [Line Items]
Estimated useful life of intangibles			2 years
Asset acquisition, Recognized identifiable assets acquired, Finite lived intangibles			$ 200,000
Contract Rights | Westland Asset Acquisition [Member]
Business Acquisition [Line Items]
Estimated useful life of intangibles		5 years
Asset acquisition, Recognized identifiable assets acquired, Finite lived intangibles		$ 300,000
Noncompete Agreements [Member] | Atherton Asset Acquisition [Member]
Business Acquisition [Line Items]
Estimated useful life of intangibles			3 years
Asset acquisition, Recognized identifiable assets acquired, Finite lived intangibles			$ 100,000
McFarland-Dyer & Associates, Inc.
Business Acquisition [Line Items]
Name of acquired entity					McFarland-Dyer & Associates, Inc
Effective date of acquisition				Aug. 1, 2021
Total consideration paid				$ 3,967,000
Issuance of common stock for acquisitions				32,143
Price per share				$ 12.85	$ 12.85
Equity issued in business combination, fair value				$ 400,000	$ 400,000
Cash, promissory note and assumed liabilities payment on business combination				3,600,000
Liability to contingent consideration				57,000,000,000	57,000,000,000
Identified intangible assets				990,000	990,000
McFarland-Dyer & Associates, Inc. | Customer Relationships and Contract Rights
Business Acquisition [Line Items]
Identified intangible assets				$ 1,000,000	$ 1,000,000
McFarland-Dyer & Associates, Inc. | Customer Relationships
Business Acquisition [Line Items]
Estimated useful life of intangibles				15 years
McFarland-Dyer & Associates, Inc. | Contract Rights
Business Acquisition [Line Items]
Estimated useful life of intangibles				2 years 4 months 24 days
McFarland-Dyer & Associates, Inc. | Promissory Note
Business Acquisition [Line Items]
Promissory note interest rate				3.25%	3.25%
Debt instrument repayment starting date				Jan. 15, 2022
Debt instrument repayment ending date				Apr. 15, 2024
McFarland-Dyer & Associates, Inc. | Promissory Note | Maximum
Business Acquisition [Line Items]
Increase in promissory note				$ 700,000
Bowman North Carolina Ltd Previously Known As He Wilson Liquidations Inc [Member]
Business Acquisition [Line Items]
Name of acquired entity	renamed HE Wilson Liquidation, Inc. as Bowman North Carolina Ltd. BNCL’s
Effective date of acquisition	Dec. 22, 2020
Total consideration paid	$ 300,000
Business acquisition, Percentage of voting interests acquired	100.00%
Business combination, Recognized identifiable assets acquired and liabilities assumed, Assets, Except indefinite lived intangible assets	$ 0
Business combination, Recognized identifiable assets acquired and liabilities assumed, Liabilities	$ 0
Business Acquisition, Transaction Costs, Other than general legal expenses						$ 0
DCPC Acquisition [Member] | Bowman Consulting DCPC [Member]
Business Acquisition [Line Items]
Name of acquired entity						Bowman Consulting DC PC
Effective date of acquisition						Dec. 31, 2020
DCPC Acquisition [Member] | Common Stock [Member] | Bowman Consulting DCPC [Member] | Mr Gary Bowman Chairman And Chief Executive Officer [Member]
Business Acquisition [Line Items]
Business acquisition, Equity interest issued or issuable, Number of shares						59,000
Business acquisition, Equity interest issued or issuable, Value assigned						$ 700,000	$ 700,000
NCPC Acquisition [Member] | Bowman Consulting NCPC [Member]
Business Acquisition [Line Items]
Name of acquired entity						Bowman Consulting NC PC
Effective date of acquisition							Dec. 31, 2020
NCPC Acquisition [Member] | Common Stock [Member] | Bowman Consulting NCPC [Member]
Business Acquisition [Line Items]
Business acquisition, Equity interest issued or issuable, Number of shares						4,632
Business acquisition, Equity interest issued or issuable, Value assigned						$ 4,400	$ 4,400

Acquisitions - Summary of Preli

Acquisitions - Summary of Preliminary Calculations of the Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Purchase Price Allocation:
Goodwill	$ 13,484	$ 9,179	$ 9,179	$ 9,179
McFarland-Dyer & Associates, Inc.
Business Acquisition [Line Items]
Total Purchase Price	3,967
Purchase Price Allocation:
Accounts Receivable	1,033
Contract assets	410
Property and equipment, net	39
Intangible Assets	990
Other assets	34
Accounts payable and other current liabilities	(70)
Contract liabilities	(230)
Total identifiable assets	2,206
Goodwill	1,761
Net assets acquired	$ 3,967

Disaggregation of Revenue and_2

Disaggregation of Revenue and Contract Balances - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Abstract]
Revenue from contracts classified as lump sum	96.20%		95.50%		95.30%
Revenue from exclusively time and material contracts	3.80%		4.50%		4.70%
Remaining performance obligations	$ 114.6		$ 114.6		$ 81.3
Contract with customer, liability, revenue recognized	$ 0.1	$ 0.4	$ 1.3	$ 4.5
Revenue recognized including contract liability					$ 32.8	$ 32.7

Disaggregation of Revenue and_3

Disaggregation of Revenue and Contract Balances - Additional Information (Details 1)	Sep. 30, 2021	Dec. 31, 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-10-01
Disaggregation Of Revenue [Line Items]
Remaining performance obligations expects to recognize	99.10%	67.00%
Remaining performance obligations, expected satisfaction period	12 months	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-10-01
Disaggregation Of Revenue [Line Items]
Remaining performance obligations expects to recognize	0.90%	33.00%
Remaining performance obligations, expected satisfaction period	0 years

Contracts in Progress - Summary

Contracts in Progress - Summary of Costs and Estimated Earnings on Contracts (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Costs incurred on uncompleted contracts	$ 148,335	$ 113,856	$ 112,417
Estimated contract earnings in excess of costs	198,528	151,423	160,242
Estimated contract earnings to date	346,863	265,279	272,659
Less: billed to date	(340,753)	(260,142)	(270,439)
Net contract assets	$ 6,110	$ 5,137	$ 2,220

Notes Receivable - Summary of N

Notes Receivable - Summary of Notes Receivable (Details) - Unsecured Notes Receivable - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Officers, employees and affiliated entities—Interest accrues annually at rates ranging from 3.25%—5.5%. The notes receivable mature through December 2021.	$ 2,393	$ 2,479	$ 8,995
Unrelated third party—Currently no interest is being accrued on this note. The note receivable matures in December 2023.	903	903	904
Total:	3,296	3,382	9,899
Less: current portion
Officers, employees and affiliates	(1,120)	(1,182)	(525)
Unrelated third party	0	0	(904)
Noncurrent portion	$ 2,176	$ 2,200	$ 8,470

Notes Receivable - Summary of_2

Notes Receivable - Summary of Notes Receivable (Parenthetical) (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Unsecured Notes Receivable, Related Parties
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, maturity	Dec. 31, 2021	Dec. 31, 2021
Unsecured Notes Receivable, Related Parties | Minimum
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, interest	3.25%	3.50%
Unsecured Notes Receivable, Related Parties | Maximum
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, interest	5.50%	15.00%
Unsecured Notes Receivable, Unrelated Third Party
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, interest	0.00%	18.00%
Notes receivable, maturity	Dec. 31, 2023	Dec. 31, 2023

Notes Receivable - Additional I

Notes Receivable - Additional Information (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Minimum | Unsecured Notes Receivable
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, interest	3.25%
Minimum | Three of Unsecured Notes Receivable
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, interest			3.50%
Maximum | Unsecured Notes Receivable
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, interest	5.50%
Maximum | Three of Unsecured Notes Receivable
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, interest		4.00%

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment for Fixed Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Total	$ 15,186	$ 14,137	$ 13,378
Less: accumulated depreciation	(10,460)	(9,912)	(9,330)
Property and Equipment, net of capital leased assets	4,726	4,225	4,048
Computer Equipment
Property Plant And Equipment [Line Items]
Total	1,260	1,276	1,427
Survey Equipment
Property Plant And Equipment [Line Items]
Total	4,444	4,444	4,444
Vehicles
Property Plant And Equipment [Line Items]
Total	460	463	473
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total	1,661	1,638	1,628
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total	6,727	5,887	4,635
Software
Property Plant And Equipment [Line Items]
Total	283	283	283
Fixed Assets Pending Lease Financing
Property Plant And Equipment [Line Items]
Total	$ 351	146
Fixed Asset Inventory [Member]
Property Plant And Equipment [Line Items]
Total		$ 146	$ 488

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation expense for fixed assets	$ 0.2	$ 0.2	$ 0.6	$ 0.6	$ 746	$ 513
Amortization expense for capital leased assets	$ 1.3	$ 0.1	$ 3.7	$ 0.2	$ 1.3	$ 0

Property and Equipment, Net -_2

Property and Equipment, Net - Summary of Property and Equipment for Capital Leased Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Total	$ 17,909	$ 12,415	$ 722
Less: accumulated amortization on leased assets	(4,771)	(1,283)	0
Capital Leased Assets, net	13,138	11,132	722
Equipment
Property Plant And Equipment [Line Items]
Total	13,393	8,590	722
Vehicles
Property Plant And Equipment [Line Items]
Total	$ 4,516	$ 3,825	$ 0

Goodwill - Summary of Goodwill

Goodwill - Summary of Goodwill Resulting From Business Acquisitions (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Goodwill [Line Items]
Beginning Goodwill	$ 9,179
Ending balance	13,484
KTA Group
Goodwill [Line Items]
Acquisition	2,544
McFarland-Dyer & Associates
Goodwill [Line Items]
Acquisition	1,761
Ending balance	$ 1,761

Intangible Assets - Summary of

Intangible Assets - Summary of Total Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (869)	$ (646)	$ (405)
Net Balance	2,108	450
Gross Amount	3,658	1,777	1,096
Net Balance	2,789	1,131	691
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross Amount	2,192	809	809
Accumulated Amortization	(534)	(382)	(225)
Net Balance	1,658	427	584
Contract Rights
Finite Lived Intangible Assets [Line Items]
Gross Amount	488	150	150
Accumulated Amortization	(185)	(150)	(112)
Net Balance	303	0	38
Leasehold
Finite Lived Intangible Assets [Line Items]
Gross Amount	160	0
Accumulated Amortization	(13)	0
Net Balance	147	0
Non-complete Agreement
Finite Lived Intangible Assets [Line Items]
Gross Amount		137	137
Accumulated Amortization	(137)	(114)	(68)
Net Balance	0	23	$ 69
Gross Amount	137	137
Net Balance		23
Domain Name
Finite Lived Intangible Assets [Line Items]
Accumulated Amortization	0	0
Net Balance	281
Gross Amount	281	281
Net Balance		281
Licensing Rights
Finite Lived Intangible Assets [Line Items]
Accumulated Amortization	0	0
Net Balance	400
Gross Amount	$ 400	400
Net Balance		$ 400

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets [Line Items]
Amortization of intangible assets	$ 100	$ 100	$ 223	$ 190	$ 241	$ 283
Domain Name
Intangible Assets [Line Items]
Intangible assets acquired					700
Licensing Rights
Intangible Assets [Line Items]
Intangible assets acquired					$ 700

Intangible Assets - Summary o_2

Intangible Assets - Summary of Weighted Average Useful Lives of Intangible Assets by Asset Class Used for Straight-line Expense Purposes (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Weighted average useful lives	12 years 9 months 18 days	5 years
Weighted average useful lives		4 years 11 months 23 days	4 years 11 months 23 days
Contract Rights
Finite Lived Intangible Assets [Line Items]
Weighted average useful lives	2 years 4 months 24 days	2 years	2 years
Leasehold
Finite Lived Intangible Assets [Line Items]
Weighted average useful lives	9 years 2 months 12 days
Non-complete Agreement
Finite Lived Intangible Assets [Line Items]
Weighted average useful lives	3 years	3 years	3 years

Intangible Assets - Summary o_3

Intangible Assets - Summary of Future amortization (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2021	$ 100
2022 2021	397	$ 181
2023 2022	336	158
2024 2023	102	111
2025	102
Thereafter	1,071
Net Balance	$ 2,108	$ 450

Bank Revolving Line of Credit_2

Bank Revolving Line of Credit and Fixed Credit Facilities - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2017
Line Of Credit Facility [Line Items]
Line of credit interest rate		3.25%		3.25%		3.80%
Notes Payable
Line Of Credit Facility [Line Items]
Debt instrument outstanding amount	$ 6,599,000		$ 6,599,000		$ 4,421,000
Minimum | Notes Payable
Line Of Credit Facility [Line Items]
Debt instrument interest rate			0.00%		0.00%	0.00%
Maximum | Notes Payable
Line Of Credit Facility [Line Items]
Debt instrument interest rate			6.25%		6.25%	6.25%
Bank of America
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity							$ 12,400,000
Borrowing base description			The Borrowing Base is computed based upon a percentage of eligible receivables within each aging category under 120 days and is further refined for customer type. Receivables more than 120 days and those from related parties or affiliates are not considered to be eligible receivables for the Borrowing Base.		The Borrowing Base is computed based upon a percentage of eligible receivables within each aging category under 120 days and is further refined for customer type. Receivables in excess of 120 days and those from related parties or affiliates are not considered to be eligible receivables for the Borrowing Base.
Line of credit facility increase in amount						$ 15,000,000
Line of credit outstanding amount					$ 800,000
Debt instrument outstanding amount					900,000
Line of credit interest expense	12,000	$ 35,000	$ 100,000	$ 200,000	300,000	$ 400,000
Bank of America | Term Loan
Line Of Credit Facility [Line Items]
Debt instrument principal amount					$ 1,000,000
Debt instrument payment terms			thirty-six months		thirty-six months
Debt instrument date of first repayment					Apr. 13, 2020
Debt instrument maturity date					Mar. 13, 2023
Debt instrument periodic payment					$ 29,294,000
Debt instrument interest rate					3.49%
Debt instrument outstanding amount	500,000		$ 500,000		$ 800,000
Bank of America | Notes Payable | Term Loan
Line Of Credit Facility [Line Items]
Debt instrument principal amount	$ 1,000,000		$ 1,000,000
Bank of America | Revolving Credit Facility
Line Of Credit Facility [Line Items]
Line of credit interest rate	3.60%	3.25%	3.60%	3.25%	3.60%	3.79%
Line of credit expiration date			Jul. 31, 2023		Jul. 31, 2021
Line of credit outstanding amount	$ 0		$ 0		$ 3,500,000
Bank of America | Revolving Credit Facility | LIBOR
Line Of Credit Facility [Line Items]
Line of credit basis spread on variable rate			1.25%
Bank of America | Fixed Line 1
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity					$ 0
Line of credit interest rate	2.83%	2.90%	2.83%	2.90%	2.91%	4.51%
Line of credit outstanding amount	$ 400,000		$ 400,000		$ 500,000	$ 700,000
Line of credit remaining borrowing capacity	$ 0		$ 0
Line of credit payment date			Aug. 31, 2018		Aug. 31, 2018
Line of credit frequency of principal payments description			sixty equal monthly installments		sixty equal monthly installments
Line of credit facility maturity date			2023-08		2023-08
Bank of America | Fixed Line 1 | Notes Payable
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity							$ 1,000,000
Bank of America | Fixed Line 1 | LIBOR
Line Of Credit Facility [Line Items]
Line of credit basis spread on variable rate			2.75%		2.75%
Bank of America | Fixed Line 2
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity					$ 0
Line of credit interest rate	2.08%		2.08%		2.15%
Line of credit basis spread on variable rate					2.00%
Line of credit outstanding amount	$ 800,000		$ 800,000		$ 900,000	0
Line of credit remaining borrowing capacity	$ 0		$ 0
Line of credit payment date			Aug. 31, 2020		Aug. 31, 2020
Line of credit frequency of principal payments description			sixty equal monthly installments		sixty equal monthly installments
Line of credit facility maturity date			2025-09		2025-09
Bank of America | Fixed Line 2 | Notes Payable
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity						$ 1,000,000
Bank of America | Fixed Line 2 | LIBOR
Line Of Credit Facility [Line Items]
Line of credit basis spread on variable rate			2.00%
Bank of America | Minimum | Revolving Credit Facility
Line Of Credit Facility [Line Items]
Line of credit interest rate	2.00%		2.00%
Line of credit basis spread on variable rate			2.35%		2.35%
Bank of America | Maximum | Revolving Credit Facility
Line Of Credit Facility [Line Items]
Line of credit interest rate	2.60%		2.60%
Line of credit basis spread on variable rate			2.95%		2.95%

Notes Payable - Schedule of Not

Notes Payable - Schedule of Notes Payable (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Notes payable		$ 4,421	$ 3,660
Less: current portion	$ (2,222)	(1,592)	(1,744)
Notes payable, less current portion	4,377	2,829	1,916
Related Parties
Debt Instrument [Line Items]
Notes payable	4,767	2,202	2,085
Related Parties | BCG Chantilly, LLC
Debt Instrument [Line Items]
Notes payable		0	225
Unrelated Third Parties | Purchase of Intangible Asset
Debt Instrument [Line Items]
Notes payable	150	0
Unrelated Third Parties | Settlement notes payable
Debt Instrument [Line Items]
Notes payable		0	625
Unrelated Third Parties | Fixed Line
Debt Instrument [Line Items]
Notes payable	1,682	2,219	$ 725
Notes Payable
Debt Instrument [Line Items]
Notes payable	$ 6,599	$ 4,421

Notes Payable - Schedule of N_2

Notes Payable - Schedule of Notes Payable (Parenthetical) (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Debt instrument, maturity date, description	mature on various dates through October 2025.	mature on various dates through October 2025.
Notes Payable | Minimum
Debt Instrument [Line Items]
Debt instrument interest rate	0.00%	0.00%	0.00%
Notes Payable | Maximum
Debt Instrument [Line Items]
Debt instrument interest rate	6.25%	6.25%	6.25%
BCG Chantilly, LLC
Debt Instrument [Line Items]
Debt instrument interest rate		12.00%	12.00%

Notes Payable - Additional Info

Notes Payable - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Notes Payable
Debt Instrument [Line Items]
Interest expense	$ 0.1	$ 0.1	$ 0.2	$ 0.2	$ 0.2	$ 0.2
Settlement notes payable | Year Two Thousand And Nineteen [Member]
Debt Instrument [Line Items]
Debt instrument principal amount								$ 1.3
Debt instrument periodic principal amount						$ 0.2
Debt instrument payment terms						quarterly installments
Settlement notes payable | Year Two Thousand And Eighteen [Member]
Debt Instrument [Line Items]
Debt instrument payment terms							quarterly installments
Debt instrument interest rate							3.55%

Notes Payable - Schedule of Fut

Notes Payable - Schedule of Future Principal Payments on Notes Payable (Details) - Notes Payable - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
2021	$ 744
2021 - 2022	2,276	$ 1,592
2022 -2023	1,932	1,263
2023 - 2024	1,286	886
2024 - 2025	361	464
2025		216
Total	$ 6,599	$ 4,421

Stock Subscription Notes Rece_2

Stock Subscription Notes Receivable - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2021
Stock Subscription Notes Receivable [Line Items]
Stock subscription notes receivable	$ 600	$ 300	$ 400
Stock Subscription Notes Receivable [Member]
Stock Subscription Notes Receivable [Line Items]
Payment of advances towards stock subscription notes receivable	500	6,683
Proceeds from collection of notes receivable	$ 200	$ 200
Stock Subscription Notes Receivable [Member] | Maximum [Member]
Stock Subscription Notes Receivable [Line Items]
Loans receivable variable interest rate spread	4.75%	4.75%
Stock Subscription Notes Receivable [Member] | Minimum [Member]
Stock Subscription Notes Receivable [Line Items]
Loans receivable variable interest rate spread	3.25%	3.25%
Stock Subscription Notes Receivable [Member] | Eighteen Shareholders [Member]
Stock Subscription Notes Receivable [Line Items]
Stock subscription notes receivable		$ 300
Stock Subscription Notes Receivable [Member] | Seventeen Shareholders [Member]
Stock Subscription Notes Receivable [Line Items]
Stock subscription notes receivable	$ 600

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Rent expense	$ 1,500,000	$ 1,900,000	$ 4,300,000	$ 6,000,000	$ 7,300,000	$ 7,400,000
Related party transaction, due from related party	400,000		400,000		600,000	300,000
BCG Chantilly, LLC
Related Party Transaction [Line Items]
Related party transaction, due from (to) related party	0		0		$ 0
Rent expense	$ 21,000	20,000	$ 61,000	60,000
BCG Chantilly, LLC | Mr. Bowman, Mr. Bruen and Mr. Hickey
Related Party Transaction [Line Items]
Ownership percentage	63.60%		63.60%		63.60%
Bowman Lansdowne Development, LLC
Related Party Transaction [Line Items]
Notes receivable	$ 500,000		$ 500,000		$ 500,000	500,000
Lansdowne Development Group, LLC
Related Party Transaction [Line Items]
Notes receivable	400,000		400,000		400,000	200,000
Accounts receivable	100,000		100,000		100,000	200,000
Bowman Realty Investments 2010, LLC
Related Party Transaction [Line Items]
Notes receivable	200,000		200,000		200,000	200,000
Alwington Farm Developers, LLC
Related Party Transaction [Line Items]
Notes receivable	1,200,000		1,200,000		1,200,000	1,200,000
Accounts receivable						400,000
Administrative, Accounting and Project Management Services
Related Party Transaction [Line Items]
Related Party transaction, cost of service			100,000	0
Related party transaction, due from related party	100,000	$ 0	100,000	$ 0
Leesburg Acquisition Partners (LAP) | Mr. Bowman, Mr. Bruen and Mr. Hickey
Related Party Transaction [Line Items]
Back charge payments	28,808
Other Than Lease Transaction | BCG Chantilly, LLC
Related Party Transaction [Line Items]
Notes due to related party						200,000
Salary | Gregory Bowman | Whole Time Employee
Related Party Transaction [Line Items]
Payment to related party towards salary					100,000	100,000
Expenses In Respect Of Real Estate Projects | BLD Three BR Thirteen And Bowman And Family Having Ownership Interest In A Real Estate Company
Related Party Transaction [Line Items]
Related Party transaction, cost of service					100,000	100,000
Unsecured Advance | Bowman | Other Noncurrent Assets
Related Party Transaction [Line Items]
Related party transaction, due from related party						800,000
Notes Receivable | Bowman
Related Party Transaction [Line Items]
Notes due to related party						5,400,000
Notes Receivable | Labovitz
Related Party Transaction [Line Items]
Notes due to related party						500,000
2015 Acquisition
Related Party Transaction [Line Items]
Related party transaction, due to related party	300,000		300,000		300,000	300,000
KTA Group Inc.
Related Party Transaction [Line Items]
Related party transaction, due to related party	$ 4,800,000		$ 4,800,000		$ 2,200,000	$ 2,000,000

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Statutory Rate					$ 410	$ 528
State income taxes, net of federal benefit					69	76
Effective rate differential for DCPC—S-corp					(59)	81
State income tax rate change					77	83
Permanent differences					68	97
Stock repurchase liability					1,474	1,078
Valuation Allowance					27
Change in tax status					170
Other					42	53
Research & development credit					(1,289)	(958)
Provision for income taxes	$ (379)	$ (979)	$ (139)	$ 467	$ 989	$ 1,038

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Line Items]
Valuation allowance	$ 0	$ 0
Federal statutory income tax rate	21.00%
Unrecognized tax benefits	$ 151	83
Research Tax Credit Carryforward [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforward balance amount	$ 1,600	$ 300

Income Taxes - Summary of Provi

Income Taxes - Summary of Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Current expense:
Federal					$ 1	$ 280
State					662	326
Total					663	606
Deferred expense (benefit):
Federal					404	468
State					(78)	(36)
Total					326	432
Provision for income taxes	$ (379)	$ (979)	$ (139)	$ 467	$ 989	$ 1,038

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Research and development credit carryover	$ 1,557	$ 275
Deferred rent expense	1,073	1,002
Intangible asset amortization	23	78
Total	2,653	1,355
Deferred tax liabilities:
Fixed asset depreciation	(2,866)	(375)
Accrual to cash adjustments	(5,398)	(6,249)
Goodwill amortization	(861)	(777)
Total	(9,125)	(7,401)
Net deferred tax liabilities	$ 6,472	$ 6,046

Employee Retirement Plan - Addi

Employee Retirement Plan - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Employer contributions	$ 1.3	$ 1.1

Stock Options - Additional Info

Stock Options - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period		5 years	4 years
Number of shares, Granted			7,434	111,982
Intrinsic value per share of options			$ 189.77	$ 89.59
Bowman Consulting Group Ltd. 2021 Omnibus Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Granted		0	7,434	111,982
Intrinsic value per share of options		$ 7.18	$ 6.43
Cash payments received from exercise of options	$ 14,855	$ 42,140	$ 62,907	$ 32,555
Compensation costs	0	0	$ 22,443	$ 121,248
Unrecognized compensation costs	$ 0	$ 0
Minimum | Bowman Consulting Group Ltd. 2021 Omnibus Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period		2 years	2 years
Maximum | Bowman Consulting Group Ltd. 2021 Omnibus Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period		5 years	5 years

Stock Options - Summary of Assu

Stock Options - Summary of Assumptions Used to Value the Options Granted (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Expected volatility	25.00%	39.00%
Expected dividend yield	0.00%	0.00%
Expected option term (in years)	5 years	2 years 6 months
Risk-free interest rate	2.50%	2.60%

Stock Options - Summary of Stat

Stock Options - Summary of Status of Stock Options Exercised, Including Substantive Options (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Number of shares Outstanding, Beginning Balance	53,277	56,404	2,950
Number of shares, Granted		7,434	111,982
Number of shares, Exercised	(33,276)	(10,561)	(55,578)
Number of shares, Expired or cancelled			(2,950)
Number of shares Outstanding, Ending Balance	20,001	53,277	56,404
Weighted Average Exercise Price, Beginning Balance	$ 5.87	$ 5.68	$ 0.34
Weighted Average Exercise Price, Granted		7.34	3.15
Weighted Average Exercise Price, Exercised	5.64	5.92	0.58
Weighted Average Exercise Price, Expired or cancelled			0.34
Weighted Average Exercise Price, Ending Balance	$ 6.25	$ 5.87	$ 5.68

Stock Options - Summary of Info

Stock Options - Summary of Information about Options Outstanding and Exercisable (Details) - $ / shares	Jan. 01, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Exercise Price	$ 6.37	$ 6.57	$ 6.37	$ 6
Total Options Outstanding	53,277	20,001	53,277	56,404	2,950
Weighted Average Remaining Life (Years)	4 years 6 months	5 years	4 years 6 months	4 years 6 months
Weighted Average Exercise Price	$ 5.87	$ 6.25	$ 5.87	$ 5.68	$ 0.34
Total Options Exercisable	53,277	20,001	53,277	56,404

Stock Bonus Plan - Additional I

Stock Bonus Plan - Additional Information (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of shares, granted	1,603,423	657,673	47,141
Options vesting period	5 years	4 years
Number of unvested stock awards	2,209,714	550,795
Number of unvested stock awards vesting start date	Oct. 1, 2021	Jan. 1, 2021
Number of unvested stock awards vesting end date	May 11, 2026	Dec. 31, 2024
Share-based compensation arrangement by share-based payment award, per share weighted average price of shares purchased		$ 12.80	$ 5.49
Unvested Stock Awards [Member]
Weighted average grant-date fair value of non-vested options outstanding		$ 12.80

Stock Bonus Plan - Summary of A

Stock Bonus Plan - Summary of Activity of Restricted Shares Subject to Forfeiture (Details) - $ / shares		9 Months Ended		12 Months Ended
		Sep. 30, 2021		Dec. 31, 2020		Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Granted		1,603,423		657,673		47,141
Number of shares, Vested		(2,209,714)		(550,795)
Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Beginning balance		702,926	[1]	156,409		188,948
Number of shares, Granted		1,603,423		657,673		47,141
Number of shares, Vested		(96,527)		(108,206)		(77,438)
Number of shares, Cancelled		(108)		(2,950)		(2,242)
Number of shares, Ending balance		2,209,714		702,926	[1]	156,409
Weighted Average Grant Price, Beginning balance		$ 12.80	[1]	$ 5.59		$ 5.48
Weighted Average Grant Price, Granted		13.95		11		5.91
Weighted Average Grant Price, Vested		12.80		6.49		5.52
Weighted Average Grant Price, Cancelled		13.02		5.49		5.49
Weighted Average Grant Price, Ending balance		$ 13.63		$ 12.80	[1]	$ 5.59
Restricted Shares | Price Based On Originally Issuance [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Beginning balance	[2]	702,926
Number of shares, Ending balance	[2]			702,926
Weighted Average Grant Price, Beginning balance	[2]	$ 10.51
Weighted Average Grant Price, Ending balance	[2]			$ 10.51
[1]	Weighted average grant price at December 31, 2020, as modified, represents the as adjusted fair value of the outstanding Stock Awards on the date of modification in connection with the settlement of the liability to common shares subject to repurchase.
[2]	Weighted average grant price at December 31, 2020 represents the grant date fair value of Stock Awards as originally issued.

Stock Bonus Plan - Summary of C

Stock Bonus Plan - Summary of Change in Liability to Common Shares Subject to Repurchase and Associated Non-Cash Compensation Expense (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Beginning Balance	$ 842	$ 8,267	$ 4,464
Non-cash compensation from ratable vesting	41	2,712	1,468
Non-cash compensation from change in fair value of liability	2	2,457	2,335
Other stock activity, net	516	(786)
Reclassification upon modification	(1,394)	(11,808)
Ending balance	$ 7	$ 842	$ 8,267

Stock Bonus Plan - Summary of F

Stock Bonus Plan - Summary of Future expense of Unvested Awards (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Future Expense Of Unvested Awards [Abstract]
2021	$ 2,527	$ 3,449
2022	8,652	2,022
2023	7,378	1,688
2024	4,545	951
Thereafter	1,547
Total	$ 24,649	$ 8,110

Redeemable Common Stock - Summa

Redeemable Common Stock - Summary of the Activity of Redeemable Common Stock (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Purchases of common stock, Shares	(13,367,535)		(13,367,535)		(7,840,244)
Issuances of new common stock	$ 428		$ 1,275		$ (533)
Purchases of common stock			$ 297	$ 45	$ 63	$ 130
Measuring date adjustment to current fair value		$ (10,235)		$ (6,795)		$ (12,863)
Redeemable Common Stock [Member]
Temporary Equity [Line Items]
Beginning Balance, Shares			0	4,646,162	4,646,162	4,942,017
Issuances of new common stock, Shares					57,230	15,783
Purchases of common stock, Shares					(713,015)	(268,745)
Controlling shareholder - net sales and purchases, Shares					1,681	(42,893)
Movement to permanent equity, Shares					(3,992,058)
Ending Balance, Shares					0	4,646,162
Beginning Balance			$ 0	$ 36,618	$ 36,618	$ 23,343
Issuances of new common stock					499	97
Purchases of common stock					(9,017)	(1,860)
Controlling shareholder - net sales and purchases					15	(200)
Collection on stock subscription notes receivable						212
Measuring date adjustment to current fair value					18,635	15,026
Movement to permanent equity					(46,750)
Ending Balance					$ 0	$ 36,618

Capital Leases - Additional Inf

Capital Leases - Additional Information (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Capital Leased Assets [Line Items]
Capital lease liability	$ 300		$ 13,500	$ 11,000
Bargain purchase price			$ 2,100	$ 1,900
Number of capital lease monthly payments		48
Capital lease monthly payments	$ 400	$ 15,562
Line of credit interest rate	3.25%	3.80%
Minimum
Capital Leased Assets [Line Items]
Capital leases payment terms on lease agreements	30 months
Maximum
Capital Leased Assets [Line Items]
Capital leases payment terms on lease agreements	50 months

Capital Leases - Schedule of Fu

Capital Leases - Schedule of Future Minimum Commitments Under Non-cancelable Capital Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Capital Leases, Future Minimum Payments, Net Minimum Payments, Fiscal Year Maturity [Abstract]
2021	$ 1,379	$ 3,916
2022	5,088	3,583
2023	3,847	2,341
2024	1,654	307
2025	653	0
Total minimum lease payments	12,621	10,147
Less: amount representing interest	(1,272)	(922)
Present value of total net minimum lease payments	11,349	9,225
Less: current portion of net minimum lease payments	(4,625)	(3,495)	$ (143)
Long-term portion of net minimum lease payments	$ 6,724	$ 5,730

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)LeaseAgreement	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)LeaseAgreement	Dec. 31, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Number of lease agreements | LeaseAgreement			3		3
Rent expense | $	$ 1.5	$ 1.9	$ 4.3	$ 6	$ 7.3	$ 7.4

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Lessee, Operating Lease, Liability, Payment, Due, Rolling Maturity [Abstract]
2021	$ 1,471	$ 5,380
2022	5,817	5,000
2023	4,613	3,838
2024	4,165	3,330
2025	3,661	2,844
Thereafter	9,378	5,975
Total	$ 29,105	$ 26,367

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Event - shares	Dec. 31, 2021	Dec. 23, 2021	Dec. 15, 2021	Nov. 10, 2021	Oct. 15, 2021	Oct. 08, 2021	Oct. 01, 2021	Apr. 30, 2021	Jan. 04, 2021	Dec. 31, 2021
Subsequent Event [Line Items]
Stock issued during period, Shares, Employee stock purchase plans										13,962
Gary Bowman, Bruce Labovitz, Michael Bruen and Robert Hickey | 21LTIP
Subsequent Event [Line Items]
Number of shares issued to executive officers				260,842
Board of Directors
Subsequent Event [Line Items]
Stockholders' equity note, stock split								29.5-to-1
Triangle Site Design
Subsequent Event [Line Items]
Business acquisition, common stock issued							65,428
PCD Engineering, Inc.
Subsequent Event [Line Items]
Business acquisition, common stock issued						36,444
BTM Engineering
Subsequent Event [Line Items]
Business acquisition, common stock issued					0
Kibart Inc
Subsequent Event [Line Items]
Business acquisition, common stock issued			38,547
1519 Surveying PLLC
Subsequent Event [Line Items]
Business acquisition, common stock issued		50,559
Terra Associates
Subsequent Event [Line Items]
Business acquisition, common stock issued	49,875
Bowman Consulting Group Ltd. 2021 Omnibus Equity Incentive Plan
Subsequent Event [Line Items]
Share based compensation arrangement by share based payment award, Shares issued in period										40,160
KTA Group
Subsequent Event [Line Items]
Business acquisition, common stock issued									53,159

Additional Disclosures - Additi

Additional Disclosures - Additional Information (Details) $ in Millions	Dec. 31, 2020USD ($)
Additional Disclosures [Abstract]
Accrued payroll taxes, current	$ 2.5