Eargo (EAR) 10-K 13 May 22 2021 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2021	May 04, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	Eargo, Inc.
Entity Central Index Key	0001719395
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		39,354,874
Entity Public Float			$ 1,069,948,866
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	EAR
Security Exchange Name	NASDAQ
Entity File Number	001-39616
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-3879805
Entity Address, Address Line One	2665 North First Street
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95134
City Area Code	650
Local Phone Number	351-7700
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	true
Documents Incorporated by Reference	None
Auditor Name	Deloitte & Touche LLP
Auditor Firm ID	34
Auditor Location	San Jose, California

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 110,500	$ 212,185
Accounts receivable, net	12,547	3,793
Inventories	5,712	2,739
Prepaid expenses and other current assets	10,873	3,740
Total current assets	139,632	222,457
Operating lease right-of-use assets	7,165	1,079
Property and equipment, net	9,551	8,034
Intangible assets, net	1,681	0
Goodwill	873	0
Other assets	1,209	1,062
Total assets	160,111	232,632
Current liabilities:
Accounts payable	9,053	6,020
Accrued expenses	9,235	9,583
Sales returns reserve	13,827	4,326
Settlement liability	34,372	0
Long-term debt, current portion	3,333	0
Other current liabilities	1,813	2,448
Deferred revenue, current portion	0	311
Lease liability, current portion	750	1,030
Total current liabilities	72,383	23,718
Lease liability, noncurrent portion	6,640	166
Long-term debt, noncurrent portion	11,924	14,837
Total liabilities	90,947	38,721
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $0.0001 par value per share; 5,000,000 shares authorized as of December 31, 2021 and 2020, respectively; zero shares issued and outstanding as of December 31, 2021 and 2020, respectively	0	0
Common stock; $0.0001 par value; 110,000,000 shares authorized as of December 31, 2021 and 2020, respectively; 39,307,093 and 38,246,601 shares issued and outstanding as of December 31, 2021 and 2020, respectively	4	4
Additional paid-in capital	425,972	392,965
Accumulated deficit	(356,812)	(199,058)
Total stockholders' equity	69,164	193,911
Total liabilities and stockholders' equity	$ 160,111	$ 232,632

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
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	$ 0.0001	$ 0.0001
Common stock, shares authorized	110,000,000	110,000,000
Common stock, shares issued	39,307,093	39,307,093
Common stock, shares outstanding	38,246,601	38,246,601

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue, net	$ 32,122	$ 69,154	$ 32,790
Cost of revenue	27,956	21,873	15,790
Gross profit	4,166	47,281	17,000
Operating expenses:
Research and development	25,232	12,045	12,841
Sales and marketing	85,759	49,525	35,725
General and administrative	49,882	20,582	12,470
Total operating expenses	160,873	82,152	61,036
Loss from operations	(156,707)	(34,871)	(44,036)
Other income (expense), net:
Interest income	21	37	627
Interest expense	(1,068)	(1,920)	(711)
Other income (expense), net	0	(1,474)	(366)
Loss on extinguishment of debt	0	(1,627)	0
Total other income (expense), net	(1,047)	(4,984)	(450)
Loss before income taxes	(157,754)	(39,855)	(44,486)
Income tax provision	0	0	0
Net loss and comprehensive loss	(157,754)	(39,855)	(44,486)
Net loss attributable to common stockholders, basic and diluted	$ (157,754)	$ (30,015)	$ (44,486)
Net loss per share attributable to common stockholders, basic and diluted	$ (4.06)	$ (3.80)	$ (173.47)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	38,899,457	7,890,375	256,452

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Preferred StockConvertible Preferred Stock	Preferred StockSeries E Convertible Preferred Stock	Preferred StockSeries D Convertible Preferred Stock
Beginning balance at Dec. 31, 2018	$ (112,999)	$ 0	$ 1,718	$ (114,717)	$ 152,015
Beginning balance, Shares at Dec. 31, 2018		231,831			11,761,159
Issuance of convertible preferred stock, upon extinguishment of convertible notes	0
Conversion of convertible preferred stock to common stock upon initial public offering	0
Issuance of convertible preferred stock, net of issuance costs							$ 865
Issuance of convertible preferred stock, net of issuance costs, Shares							64,653
Stock-based compensation	1,339		1,339
Exercise of stock options	43		43
Exercise of stock options, Shares		34,112
Net loss and comprehensive loss	(44,486)			(44,486)
Ending balance at Dec. 31, 2019	(156,103)		3,100	(159,203)	$ 152,880
Ending balance, Shares at Dec. 31, 2019		265,943			11,825,812
Issuance of convertible preferred stock, upon extinguishment of convertible notes	12,818					$ 12,818
Issuance of convertible preferred stock, upon extinguishment of convertible notes, Shares						1,889,548
Gain on extinguishment of Series C and Series C-1 convertible preferred stock	9,840		9,840		$ (9,840)
Conversion of convertible preferred stock to common stock upon initial public offering, Shares		28,196,388			(24,229,281)
Conversion of convertible preferred stock to common stock upon initial public offering	223,125	$ 3	223,122		$ (223,125)
Conversion of convertible preferred stock warrants to common stock warrants upon initial public offering	1,931		1,931
Issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs	148,502	$ 1	148,501
Issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs, Shares		9,029,629
Exercise of common stock warrants, Shares		107,790
Issuance of convertible preferred stock, net of issuance costs						$ 67,267
Issuance of convertible preferred stock, net of issuance costs, Shares						10,513,921
Stock-based compensation	5,292		5,292
Exercise of stock options	1,179		1,179
Exercise of stock options, Shares		646,851
Net loss and comprehensive loss	(39,855)			(39,855)
Ending balance at Dec. 31, 2020	193,911	$ 4	392,965	(199,058)	$ 0
Ending balance, Shares at Dec. 31, 2020		38,246,601			0
Issuance of convertible preferred stock, upon extinguishment of convertible notes	0
Conversion of convertible preferred stock to common stock upon initial public offering	0
Stock-based compensation	28,609		28,609
Exercise of stock options and release of restricted stock units	1,724		1,724
Exercise of stock options and release of restricted stock units, Shares		885,749
Issuance of common stock in connection with employee stock purchase plan	$ 2,674		2,674
Issuance of common stock in connection with employee stock purchase plan, Shares		174,743
Exercise of stock options, Shares	859,200
Net loss and comprehensive loss	$ (157,754)			(157,754)
Ending balance at Dec. 31, 2021	$ 69,164	$ 4	$ 425,972	$ (356,812)	$ 0
Ending balance, Shares at Dec. 31, 2021		39,307,093			0

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Initial Public Offering
Net of underwriting discounts and commissions and other offering costs	$ 14,031
Series D Convertible Preferred Stock
Convertible preferred stock, issuance costs		$ 0
Series E Convertible Preferred Stock
Convertible preferred stock, issuance costs	$ 4,056

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (157,754)	$ (39,855)	$ (44,486)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,202	2,525	1,528
Stock-based compensation	27,731	5,089	1,339
Non-cash interest expense and amortization of debt discount	420	1,513	297
Non-cash operating lease expense	1,063	1,128	0
Bad debt expense	9,615	2,352	313
Loss on disposal of property and equipment	155	0	24
Loss on extinguishment of debt	0	1,627	0
Change in fair value of financial instruments	0	1,471	274
Changes in operating assets and liabilities:
Accounts receivable	(18,369)	(4,094)	(1,399)
Inventories	(2,973)	141	(720)
Prepaid expenses and other current and noncurrent assets	(7,383)	(1,636)	(641)
Accounts payable	3,130	187	163
Accrued expenses	(368)	3,900	2,692
Sales returns reserve	9,501	567	1,046
Settlement liability	34,372	0	0
Other current and noncurrent liabilities	(946)	240	462
Operating lease liabilities	(852)	(1,196)	0
Net cash used in operating activities	(98,456)	(26,041)	(39,108)
Investing activities:
Purchases of property and equipment	(882)	(1,624)	(2,167)
Capitalized software development costs	(3,842)	(3,455)	(1,692)
Cash paid for acquisition of business	(2,863)	0	0
Net cash used in investing activities	(7,587)	(5,079)	(3,859)
Financing activities:
Proceeds from stock options exercised	1,724	1,179	43
Proceeds from employee stock purchase plan purchases	2,674	0	0
Proceeds from issuance of common stock upon initial public offering, net of underwriting discounts and commissions	0	151,156	0
Payments of other offering costs related to the initial public offering	(40)	(2,614)	(758)
Proceeds from convertible preferred stock issuance, net of issuance costs	0	67,867	865
Proceeds from issuance of convertible notes, net of issuance costs	0	10,053	0
Proceeds from debt financing	0	15,000	5,000
Debt repayments	0	(12,720)	0
Proceeds from PPP loan	0	4,574	0
Repayment of PPP loan	0	(4,574)	0
Net cash provided by financing activities	4,358	229,921	5,150
Net increase (decrease) in cash and cash equivalents and restricted cash	(101,685)	198,801	(37,817)
Cash and cash equivalents and restricted cash at beginning of period	212,185	13,384	51,201
Cash and cash equivalents and restricted cash at end of period	110,500	212,185	13,384
Supplemental disclosure of cash flow information:
Cash paid for taxes	107	63	0
Cash paid for interest	646	398	395
Non-cash operating activities:
Lease liability obtained in exchange for right-of-use asset	7,046	2,392	0
Non-cash investing and financing activities:
Property and equipment and capitalized software costs in accounts payable and accrued liabilities	357	393	515
Stock-based compensation included in capitalized software costs	878	203	0
Convertible preferred stock issuance costs included in accounts payable	600	600	0
Common stock issued on conversion of convertible preferred stock upon initial public offering	0	223,125	0
Conversion of convertible preferred stock warrants to common stock warrants and related reclassification of convertible preferred stock warrant liability to additional paid in capital	0	1,931	0
Offering costs in accounts payable and accrued liabilities	0	40	424
Issuance of Series E convertible preferred stock upon extinguishment of convertible notes	$ 0	$ 12,818	$ 0

Description of Business and Oth

Description of Business and Other Matters	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Other Matters	Note 1. Description of business and other matters The Company is a medical device company dedicated to improving the quality of life of people with hearing loss. The Company’s innovative product and go-to-market DOJ investigation and settlement and claims audits On September 21, 2021, Eargo, Inc. (the “Company”) was informed that it was the target of a criminal investigation by the U.S. Department of Justice (the “DOJ”) related to insurance reimbursement claims the Company submitted on behalf of its customers covered by various federal employee health plans under the Federal Employee Health Benefits (“FEHB”) program. The investigation also pertained to Eargo’s role in customer reimbursement claim submissions to federal employee health plans (collectively, the “DOJ investigation”). Additionally, the Company’s largest third-party payor conducted an audit of insurance reimbursement claims (“claims”) submitted by the Company (the “Primary Audit”), which included a review of medical records. The Company was informed by the third-party payor conducting the Primary Audit that the DOJ was the principal contact related to the subject matter of the Primary Audit. On January 4, 2022, the DOJ confirmed to the Company that the investigation had been referred to the Civil Division of the DOJ and the U.S. Attorney’s Office for the Northern District of Texas and the criminal investigation was no longer active. On April 29, 2022, the Company entered into a civil settlement agreement with the U.S. government that resolved the DOJ investigation related to the Company’s role in customer reimbursement claim submissions to various federal employee health plans under the FEHB program. The settlement agreement provided for the Company’s payment of approximately million to the U.S. government and resolved allegations that the Company submitted or caused the submission of claims for payment to the FEHB program using unsupported hearing loss-related diagnostic codes. From the time the Company learned of the DOJ investigation and until December 8, 2021, the Company continued to process orders for customers with potential insurance benefits (including FEHB program members) but suspended all claims submission activities and has offered affected customers ( i.e. Beginning on December 8, 2021, the Company made the decision to stop accepting insurance benefits as a method of direct payment and it is uncertain when, if ever, the Company will resume accepting insurance benefits as a method of direct payment. While the Company intends to work with the government and third-party payors at the appropriate time with the objective of validating and establishing processes to support any future claims that it may submit for reimbursement, the Company may not be able to arrive at acceptable processes or submit any future claims. Total life-to-date payments the Company has received through December 31, 2021 from the government in relation to claims submitted under the FEHB program, net of any product returns and associated refunds, were approximately $44 million. As discussed further in Note 6, based on the settlement agreement with the U.S. government, the Company has recorded a settlement liability of $34.4 million as of December 31, 2021. The settlement amount was treated as consideration payable to a customer and was recorded as a reduction of revenue in the consolidated statements of operations and comprehensive loss during the year ended December 31, 2021. The Company determined that customer transactions using insurance benefits as a method of direct payment occurring subsequent to learning of the DOJ investigation on September 21, 2021 did not meet the criteria for revenue recognition under Accounting Standards Codification (“ASC”) 606. As such, the Company did not recognize revenue for shipments to customers with potential insurance benefits, substantially all of whom were covered under the FEHB program, subsequent to that date. The Company estimates that a majority of customers with unsubmitted claims as of December 31, 2021 will choose to return the hearing aid system if their insurance provider denies their claim or the claim is ultimately not submitted by the Company for payment, resulting in an increase in expected product returns from such transactions that occurred prior to September 21, 2021. As a result, the Company recorded $13.3 million of estimated sales returns as a reduction in revenue in the third quarter of 2021 related to shipments to customers with potential insurance benefits. Of the $13.8 million sales returns reserve recorded as of December 31, 2021, $11.4 million relates to unsubmitted claims that are included in accounts receivable, net. Returns associated with unsubmitted claims will reduce the sales returns reserve, with a corresponding reduction in the related accounts receivable at the time the product is returned. Further, the Company also estimates that, in addition to the customers who choose to return their hearing aid systems, a significant number of customers whose claims are denied by insurance providers or not submitted by the Company for payment may not pay for or return the hearing aid system. The $9.6 million in bad debt expense recorded during the year ended December 31, 2021 is primarily based on this estimate. Of the $9.6 million recorded to bad debt expense during the year ended December 31, 2021, $5.8 million relates to submitted claims that have been denied or have not been paid and was written off during the year ended December 31, 2021. Notwithstanding the settlement, the Company remains subject to prepayment review of claims by its largest third-party payor before any insurance payments are made. The Company does not intend to submit any claims through the FEHB program until it is able to align with the Office of Personnel Management (the “OPM”) on and establish processes for supporting the submission of these claims, and the Company may be unable to do so. Liquidity and going concern The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities during the normal course of business. The Company has incurred losses and negative cash flows from operations since its inception and management expects to incur additional substantial losses in the foreseeable future. As of December 31, 2021, the Company had cash and cash equivalents of million and an accumulated deficit of The Company believes that without any future financing, its current resources are insufficient to satisfy its obligations as they become due within one year after the date that the financial statements are issued. The negative cash flows and current lack of financial resources of the Company raise substantial doubt as to the Company’s ability to continue as a going concern. The Company’s future operating requirements will be substantial and it will need to raise significant additional resources to fund its operations through equity or debt financing, or some variation thereof. The Company is currently exploring fundraising opportunities to meet these capital requirements. If the Company is unable to raise additional funding to meet its operational needs, it will be forced to limit or cease its operations. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of the uncertainty. While the extent to which the Company is able to validate and establish processes to support the submission of claims for reimbursement to health plans, including those under the FEHB program, if at all, in the future, and the future impacts of the anticipated implementation of a pending over-the-counter (“OTC”) hearing aid regulatory framework (which may lead insurance providers to take actions limiting the Company’s

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Summary of significant accounting policies Basis of presentation and principles of consolidation The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The consolidated financial statements include the accounts of Eargo, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. Use of estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions, and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates and assumptions made in the accompanying consolidated financial statements include, but are not limited to, the sales returns reserve, the present value of lease liabilities, the fair value of equity securities, the fair value of financial instruments, the allowance for credit losses, the net realizable value of inventory, the fair value of assets acquired in a business combination, the useful lives of long-lived assets, accrued product warranty reserve, legal and other contingencies, certain other accruals and recoverability of the Company’s net deferred tax assets and the related valuation allowance. Management periodically evaluates its estimates, which are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates. Cash and cash equivalents Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less from the purchase date. Cash equivalents consist primarily of amounts invested in money market accounts. Concentration of credit risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of demand deposit accounts, money market accounts and accounts receivable, including credit card receivables. The Company maintains its cash and cash equivalents, which may, at times, exceed federally insured limits, with financial institutions of high credit standing. As of December 31, 2021, the Company has not experienced any losses on its deposit accounts and money market accounts. As of December 31, 2021, the Company does not believe there is significant financial risk from nonperformance by the issuers of the Company’s deposit accounts and money market accounts. Approximately 93% and 74% of the Company’s gross accounts receivable as of December 31, 2021 and 2020, respectively, were for customers with insurance benefits, substantially all of whom were covered under the FEHB program. Furthermore, approximately 90% and 45% of the Company’s gross accounts receivable as of December 31, 2021 and 2020, respectively, were related to shipments of Eargo hearing aids to customers insured under a single insurance plan whose claims are processed through the Company’s largest third-party payor, which conducted the Primary Audit. The increase in gross accounts receivable as of December 31, 2021 was primarily due to the Primary Audit, during which certain claims with a service date after March 1, 2021 have not yet and may never be submitted for reimbursement. We remain subject to a prepayment review of claims by the payor who conducted the Primary Audit. Please see caption “DOJ investigation and settlement and claims audits” in Note 1 Fair value measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. The Company measures fair value based on a three-level hierarchy of inputs, of which the first two are considered observable and the last unobservable. Unobservable inputs reflect the Company’s own assumptions about current market conditions. The Company maximizes the use of observable inputs, where available, and minimizes the use of unobservable inputs when measuring fair value. The three-level hierarchy of inputs is as follows: Level Level Level To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the consolidated balance sheets for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The fair value of the Company’s outstanding term loan is estimated using the net present value of the payments, discounted at an interest rate that is consistent with a market interest rate, which is a Level 2 input. The fair value of the outstanding term loan approximates the carrying amount as the term loan bears a floating rate that approximates the market interest rate. Refer to Note 3 for discussion of certain other financial instruments. Accounts receivable, net Accounts receivable represents amounts due from third-party institutions for credit card and debit card transactions and trade accounts receivable. Trade accounts receivable are primarily insurance claims receivable amounts due from customers, which includes third-party payors and end-users. The Company adopted Accounting Standards Codification (“ASC”) Topic 326, Financial Instruments—Credit Losses effective January 1, 2021 Inventories Inventories are stated at the lower of standard cost (which approximates actual cost on a first-in, first-out Property and equipment, net Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization on property and equipment is calculated using the straight-line method over the estimated useful lives of the assets, generally three Capitalized software development costs The Company capitalizes software purchased for internal use and qualified costs incurred in connection with the development of internal use software. Purchased software consists of software products and licenses, which are amortized over the lesser of their estimated useful life or the contractual term. Internally developed software costs incurred in the preliminary stages of development are expensed as incurred. Once an application has reached the development stage, internal and external direct costs of the development are capitalized until the software is substantially complete and ready for its intended use. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable that the expenditure will result in additional functionality. Internal use software is amortized on a straight-line basis over its estimated useful life, generally three years. Post-implementation activities including training and maintenance are expensed as incurred. Capitalized costs less accumulated amortization are recorded as a component of property and equipment, net on the consolidated balance sheets. Goodwill, finite-lived acquired intangible assets, and impairment Goodwill represents the excess of the purchase price paid over the fair value of tangible and identifiable intangible net assets acquired in business combinations. In November of each fiscal year, or more frequently if indicators of impairment exist, management performs a review to determine if the carrying value of goodwill is impaired. Impairment testing is performed at the reporting unit level. The Company’s intangible assets consist of intangible assets acquired in a business combination. These assets are amortized using the straight-line method over their estimated useful lives ranging from on The Company evaluates its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or group of assets may not be fully recoverable. Recoverability is measured by comparing the carrying amount to the future net undiscounted cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the projected discounted future net cash flows arising from the asset. Leases The Company adopted ASC Topic 842 Leases Leases right-of-use ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized based on the present value of lease payments over the lease term at the commencement date of the lease. ROU assets also include any initial direct costs incurred and any lease payments made at or before the lease commencement date, less any lease incentive received. As the Company’s leases do not provide an implicit interest rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease expense is recognized on a straight-line basis over the lease term. Product warranty The Company provides a one-year two-year Convertible preferred stock warrant liability The Company accounts for its convertible preferred stock warrants issued in connection with its various financing transactions based upon the characteristics and provisions of the instrument. Convertible preferred stock warrants classified as liabilities are recorded on the consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value at each reporting period, with the changes in fair value recognized as other income (expense), net in the consolidated statements of operations and comprehensive loss. The Company adjusted the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants were no longer considered liability instruments. Upon the closing of the IPO in October 2020 Derivative liability The Company’s convertible notes issued in 2020 (the “2020 Notes”) contain certain features that meet the definition of embedded derivatives requiring bifurcation from the 2020 Notes as a separate compound financial instrument. The derivative liability is initially measured at fair value on issuance and is subject to remeasurement at each reporting period with changes in fair value recognized in other income (expense), net in the consolidated statements of operations and comprehensive loss. In July 2020, the derivative liability was settled upon the extinguishment of the 2020 Notes. Refer to Note 3 and Note 8 for further discussion. Revenue recognition The Company’s revenue is generated from the sale of products (hearing aid systems and related accessories) and services (extended warranties). These products and services are primarily sold directly to customers through the Eargo website and the Company’s sales representatives. Under ASC 606, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services by following a five step process: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. Identify the contract with a customer Identify the performance obligations in the contract one-time i.e. The Company has elected to treat shipping and handling activities performed after a customer obtains control of products as a fulfillment activity. Determine the transaction price and allocation to performance obligations 45-day method of direct payment). Please see caption “DOJ investigation and settlement and claims audits” in Note 1 for more information regarding the extended right of return. To estimate product returns, the Company analyzes various factors, including historical return levels, current economic trends, and insurance coverage. Based on this information, the Company reserves a percentage of product sale revenue and accounts for the estimated impact as a reduction in the transaction price. Consideration paid or payable to a customer that is not for a distinct good or service is accounted for as a reduction of the transaction price and recorded as a reduction in revenue in the period it becomes payable. Allocate the transaction price to the performance obligations in the contract. Recognize revenue when or as the Company satisfies a performance obligation Contract costs The Company applies the practical expedient to recognize the incremental costs of obtaining a contract as expense when incurred if the amortization period would be one year or less. These incremental costs include processing fees paid to third-party financing vendors, who provide the Company’s customers with the option to finance their purchases. If a customer elects to utilize this service, the Company receives a non-recourse Cost of revenue Cost of revenue consists of expenses relating to the cost of finished goods, freight, personnel costs, consumables, product warranty costs, transaction fees including processing fees paid to third-party financing vendors, transaction fees, reserves for excess and obsolete inventory, depreciation and amortization, and related overhead. Research and development Research and development expenses consist of personnel costs, travel expenses, tools, prototype materials and product certification and are charged to expense as incurred. Sales and marketing Sales and marketing expenses consist of personnel costs, travel expenses, consulting fees, public relations costs, direct marketing, advertising and promotional expenses and allocated facility overhead costs. The Company recorded advertising costs, which are expensed as incurred, of $41.9 million, $23.6 million and $18.6 million for the years ended December 31, 2021, 2020 and 2019, respectively. Stock-based compensation The Company accounts for stock-based awards at fair value. The fair value of restricted stock units (“RSUs”) is equal to the closing price of the Company’s common stock on the grant date. The fair value of stock options and purchase rights under an employee stock purchase plan are estimated on the date of grant using the Black-Scholes option-pricing model. The fair value of the underlying common stock is the closing price of the Company’s common stock for grants subsequent to the Company’s IPO. The expected volatility is derived from the historical stock volatilities of comparable peer public companies within the Company’s industry that are considered to be comparable to the Company’s business over a period equivalent to the expected term of the awards due to limited trading history of the Company’s common stock. The expected term for employee option grants is determined using the simplified method due to a lack of sufficient data points. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The expected dividend yield is zero as the Company has not paid nor does it anticipate paying any dividends on its common stock in the foreseeable future. For stock-based awards that vest subject to the satisfaction of a service requirement, the fair value measurement date is the date of grant and the expense is recognized on a straight-line basis over the requisite service period. For stock-based awards with performance-based vesting conditions, the expense is recognized over the vesting period using the accelerated attribution method. The Company accounts for forfeitures as they occur. Income taxes The Company uses the asset and liability method to account for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized. Financial statement effects of uncertain tax positions are recognized when it is more-likely-than-not Segments Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its Chief Executive Officer. To date, the Company has viewed its operations and manages its business as one operating and reportable segment, with all operations in the United States. Employee benefit plan The Company sponsors a qualified 401(k) defined contribution plan covering eligible employees. Participants may contribute a portion of their annual compensation limited to a maximum annual amount set by the Internal Revenue Service. There have been no employer contributions under this plan to date. Net loss per share attributable to common stockholders The Company follows the two-class two-class two-class Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration for potential dilutive securities. Diluted net loss attributable to common stockholders is computed by adjusting net loss attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and common share equivalents of potentially dilutive securities outstanding for the period. Potentially dilutive securities are not assumed to have been issued if their effect is anti- dilutive Emerging growth company status The Company ceased to be an emerging growth company (“EGC”) on December 31, 2021 because the aggregate worldwide market value of the voting and non-voting non-affiliates Recently adopted accounting pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments January 1, 2021 Recent accounting pronouncements not yet adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes In August 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) 815-40) 470-20

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair value measurements There were no financial assets and liabilities outstanding that were remeasured at fair value on a recurring basis as of December 31, 2021 or December 31, 2020. Convertible preferred stock warrant liability The Company estimates the fair value of its convertible preferred stock warrant liability using the Black-Scholes option-pricing model, assumptions that are based on the individual characteristics of the warrants on the valuation date, and assumptions related to the fair value of the underlying stock, expected volatility, expected life, dividends, and risk-free interest rate. Due to the nature of these inputs, the warrants are considered a Level 3 liability. Upon the closing of the IPO in October 2020, the convertible preferred stock warrants were converted into warrants to purchase common stock and the warrant liabilities were reclassified to additional paid-in capital. The following table provides a summary of the change in the estimated fair value of the Company’s convertible preferred stock warrant liability: Total Balance—December 31, 2019 396 Fair value of convertible preferred stock warrants issued in connection with debt financing 270 Change in fair value of warrant liability 1,265 Conversion of preferred stock warrants to common stock warrants upon the closing of the IPO (1,931 ) Balance—December 31, 2020 $ — The fair value of the convertible preferred stock warrants, which were converted to common stock warrants upon the closing of the IPO in October 2020, was determined using the following assumptions: Valuation assumptions: December 31, Expected volatility 67%-71% Expected term 2.17-9.9 years Risk-free interest rate 0.15%-0.75% Dividend yield — Derivative liability The 2020 Notes contain embedded derivatives requiring bifurcation as a single compound derivative instrument. The Company estimated the fair value of the derivative liability on issuance using a “with-and-without” “with-and-without” as-is The following table provides a summary of the change in the estimated fair value of the Company’s derivative liability: Total Balance—December 31, 2019 $ — Initial fair value of derivative liability 2,879 Change in fair value of derivative liability 206 Extinguishment of derivative liability (3,085 ) Balance—December 31, 2020 $ — In July 2020, the embedded derivative liability was settled upon the extinguishment of the 2020 Notes. Refer to Note 8 for further discussion.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Note 4. Balance sheet components Inventories Inventories consist primarily of raw materials related to component parts and finished goods. The following is a summary of the Company’s inventories by category: December 31, 2021 2020 (in thousands) Raw materials $ 1,905 $ 853 Finished goods 3,807 1,886 Total inventories $ 5,712 $ 2,739 Prepaid expenses and other current assets Prepaid expenses and other current assets consist of the following: December 31, 2021 2020 (in thousands) Advanced payroll deposits $ 3,889 $ — Prepaid insurance fees 2,945 1,931 Prepaid marketing costs 1,948 245 Prepaid software subscription 1,468 995 Other 623 569 Total prepaid expenses and other current assets $ 10,873 $ 3,740 Property and equipment, net Property and equipment, net, consists of the following: December 31, 2021 2020 (in thousands) Capitalized software $ 11,569 $ 6,744 Tools and lab equipment 4,712 4,426 Furniture and fixtures 906 906 Leasehold improvements 861 757 Computer and equipment 401 288 18,449 13,121 Less accumulated depreciation and amortization (8,898 ) (5,087 ) Total property and equipment, net $ 9,551 $ 8,034 Depreciation and amortization expense for the years ended December 31, 2021, 2020 and 2019 amounted to $4.2 million, $2.5 million and $1.5 million, respectively, which includes amortization of capitalized software costs of $2.1 million, $0.8 million and $0.3 million, respectively. Accrued expenses Accrued expenses consist of the following: December 31, 2021 2020 (in thousands) Accrued compensation $ 4,845 $ 5,861 Accrued warranty reserve 4,014 2,390 Refunds due to customers 376 581 Accrued vendor costs — 751 Total accrued expenses $ 9,235 $ 9,583 Sales returns reserve The sales returns reserve consists of the following activity: Year ended December 31, 2021 2020 2019 (in thousands) Sales returns reserve, beginning balance $ 4,326 $ 3,759 $ 2,713 Reduction of revenue 37,674 22,676 17,739 Utilization of sales returns reserve (28,172 ) (22,109 ) (16,693 ) Sales returns reserve, ending balance $ 13,828 $ 4,326 $ 3,759 The $37.7 million of estimated sales returns recorded as a reduction in revenue during the year ended December 31, 2021 includes $13.3 million recorded during the third quarter of 2021 primarily based on the Company’s estimate that a majority of customers with unsubmitted claims will choose to return the hearing aid system if their insurance provider denies their claim or the claim is ultimately not submitted by the Company for payment. Of the $13.8 million sales returns reserve recorded as of December 31, 2021, $11.4 million relates to unsubmitted claims that are included in accounts receivable, net. Returns associated with unsubmitted claims will reduce the sales returns reserve, with a corresponding reduction in the related accounts receivable at the time the product is returned. Allowance for credit losses The allowance for credit losses consists of the following activity: Year ended December 31, 2021 2020 2019 (in thousands) Allowance for credit losses, beginning balance $ 1,868 $ 225 $ — Charged to expense 9,615 2,352 225 Accounts written off, net of recoveries (6,645 ) (709 ) — Allowance for credit losses, ending balance $ 4,838 $ 1,868 $ 225 The $9.6 million in bad debt expense recorded during the year ended December 31, 2021 is primarily based on the Company’s estimate that a significant number of customers with an extended right of return and whose claims are denied by insurance providers or not submitted by the Company for payment may not pay for or return the hearing aid system. Of the Accrued warranty reserve The accrued warranty reserve consists of the following activity: Year ended December 31, 2021 2020 2019 (in thousands) Accrued warranty reserve, beginning balance $ 2,390 $ 450 $ 53 Charged to cost of revenue 3,229 3,178 1,589 Utilization of accrued warranty reserve (1,605 ) (1,238 ) (1,192 ) Accrued warranty reserve, ending balance $ 4,014 $ 2,390 $ 450

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Acquisitions	Note 5. Acquisitions In June 2021, the Company completed the purchase of certain web-based in-person The table below presents the purchase price allocation: (in thousands) Goodwill $ 873 Intangible assets 1,990 Total fair value of consideration $ 2,863 The intangible assets acquired in the Clementine acquisition are comprised primarily of developed technologies and have a weighted-average amortization period of 3.6 years as of the date of the acquisition.

Commitment and Contingencies

Commitment and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingencies	Note 6. Commitments and contingencies Operating leases The Company has entered into non-cancelable New San Jose lease In September 2021, the Company entered into a lease agreement, as amended, for approximately 30,000 square feet of office and laboratory space located in San Jose, California, which the Company plans to use as its headquarters starting in early 2022. The lease commenced in September 2021 and has a 93-month 60-month The Company recorded a ROU asset of Nashville lease In February 2021, the Company amended the operating lease for its Nashville, Tennessee office to extend the term of the initial lease through March 2023 and reduce the size of office space leased. This extension was accounted for as a lease modification and the Company recorded an increase to the ROU asset and lease liability of $0.4 million at the time of the amendment. As of December 31, 2021, the Company recorded an aggregate ROU asset of $7.2 million and an aggregate lease liability of $7.4 million in the accompanying consolidated balance sheet. The ROU asset and corresponding lease liability were estimated using a weighted-average incremental borrowing rate of 7.7%. The weighted-average remaining lease term is 7.1 years. For the years ended December 31, 2021 and 2020, the Company incurred $1.5 million and $1.3 million of operating lease costs. Variable lease payments for operating expenses and costs related to short-term leases were immaterial for the years ended December 31, 2021 and 2020. For the years ended December 31, 2021 and 2020, cash paid for amounts included in the measurement of operating lease liabilities was $1.4 million and $1.2 million, respectively. As of December 31, 2021, undiscounted future minimum lease payments due under the non-cancelable Operating leases (in thousands) 2022 $ 1,327 2023 1,114 2024 1,081 2025 1,331 2026 1,372 Thereafter 3,607 Total minimum future lease payments 9,832 Present value adjustment for minimum lease commitments (2,442 ) Total lease liability $ 7,390 Legal and other contingencies The Company is involved in legal proceedings in the ordinary course of its business and may become involved in additional legal proceedings. Other than those listed below, the Company does not believe that any lawsuits or claims currently pending against it, individually or in the aggregate, are material or will have a material adverse effect on its financial condition, results of operations or cash flows. The Company may enter into settlement discussions, and may enter into settlement agreements, if it believes settlement is in the best interest of the Company and its shareholders. Unless stated otherwise, the matters discussed below, if decided adversely or settled by the Company, individually or in the aggregate, may result in a liability material to the Company’s financial condition, results of operations or cash flows. The Company is also subject to review from federal and state taxing authorities in order to validate the amounts of income, sales and/or use taxes which have been claimed and remitted. The Company has estimated exposure and established reserves for its estimated sales tax audit liability. In the normal course of business, the Company may agree to indemnify third parties with whom it enters into contractual relationships, including customers, lessors, and parties to other transactions with the Company, with respect to certain matters. The Company has agreed, under certain conditions, to hold these third parties harmless against specified losses, such as those arising from a breach of representations or covenants, other third-party claims that the Company’s products, when used for their intended purposes, infringe the intellectual property rights of such other third parties, or other claims made against certain parties. It is not possible to determine the maximum potential amount of liability under these indemnification obligations due to the Company’s limited history of prior indemnification claims and the unique facts and circumstances that are likely to be involved in any particular claim. DOJ Investigation and Settlement. principal contact related to the subject matter of the audit. In addition to such audit, the Company has been subject to a number of other audits of insurance reimbursement claims submitted to additional third-party payors. One of these claims audits does not relate to claims submitted under the FEHB program. On January 4, 2022, the DOJ confirmed to the Company that the investigation had been referred to the Civil Division of the DOJ and the U.S. Attorney’s Office for the Northern District of Texas and the criminal investigation was no longer active. On April 29, 2022, the Company entered into a civil settlement agreement with the U.S. government that resolved the DOJ investigation, including allegations that the Company violated the False Claims Act by knowingly submitting or causing the submission of false claims for payment under the FEHB The Company recorded a million settlement liability in the consolidated balance sheets as of December 31, 2021 in connection with the settlement. The settlement amount was treated as consideration payable to a customer and was recorded as a reduction in revenue in the consolidated statements of operations and comprehensive loss during the year ended December 31, 2021. The settlement of the investigation may not resolve all of the audits of insurance reimbursement claims by additional third-party payors, and additionally the Company remains subject to a prepayment review of claims by the payor who conducted the Primary Audit. The Company will need to work with the government (including the OPM) and third-party payors to potentially validate and establish processes to support any future claims that it may submit for reimbursement, and there are no guarantees that the Company will be able to arrive at any such acceptable processes or submit any future claims. The Company does not intend to submit any claims through the FEHB program until it is able to align with the OPM on and establish processes for supporting the submission of these claims. Securities Class Action . Fazio v. Eargo, Inc., Christian Gormsen, & Adam Laponis. 21-cv-07848 Chung v. Eargo, Inc., Christian Gormsen, & Adam Laponis. 21-cv-08597 IBEW Local 353 Pension Plan v. Eargo, Inc., Christian Gormsen, Adam Laponis, Josh Makower, Juliet Bakker, Peter Tuxen Bisgaard, Doug Hughes, Geoff Pardo, Nina Richardson, A. Brooke Seawell, David Wu, J.P. Morgan Securities LLC, BofA Securities, Inc., Wells Fargo Securities, LLC, & William Blair & Company, L.L.C. 21-cv-08747 In re Eargo, Inc. Securities Litigation 21-cv-08597-CRB, The Company intends to vigorously defend the Securities Class Action and cannot reasonably estimate any loss or range of loss that may arise from the litigation. Accordingly, the Company can provide no assurance as to the scope and outcome of this matter and no assurance as to whether its business, financial position, results of operations or cash flows will not be materially adversely affected. Derivative Action. Wolfson v. Christian Gormsen, Joshua Makower, Douglas J. Hughes, Nina Louise Richardson, Katie J. Bayne, Peter Tuxen Bisgaard, A. Brooke Seawell, David Wu, and Eargo, Inc. No. 21-cv-09342 The defendants intend to vigorously defend the Derivative Action and cannot reasonably estimate any loss or range of loss that may arise from the litigation. Accordingly, the Company can provide no assurance as to the scope and outcome of this matter and no assurance as to whether its business, financial position, results of operations or cash flows will not be materially adversely affected.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Note 7. Goodwill and intangible assets Goodwill The changes in the carrying amount of goodwill are as follows: Total (in thousands) Balance December 31, 2020 $ — Addition due to business acquisition 873 Balance December 31, 2021 $ 873 There was no impairment of goodwill during the year ended December 31, 2021. Intangible assets, net Intangible assets, net consist of the following as of December 31, 2021: Gross Accumulated Net carrying (in thousands) Developed technologies $ 1,700 $ 212 $ 1,488 Other 290 97 193 Total intangible assets, net $ 1,990 $ 309 $ 1,681 Amortization expense was $0.3 million for the year ended December 31, 2021. The Company did not record any impairments of intangible assets during the year ended December 31, 2021. The following table summarizes estimated future amortization expense of finite-lived intangible assets, net as of December 31, 2021: Amount (in thousands) 2022 $ 618 2023 425 2024 425 2025 213 Total $ 1,681

Debt Obligations

Debt Obligations	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt Obligations	Note 8. Debt obligations 2018 Loan Agreement In June 2018, the Company entered into a Loan and Security Agreement (the “2018 Loan Agreement”) with Silicon Valley Bank. Under the terms of the 2018 Loan Agreement, Silicon Valley Bank made available to the Company term loans in an aggregate principal amount of $12.5 million and the Company borrowed $7.0 million in 2018. The Company’s existing subsidiaries are, and any additional future domestic subsidiaries of the Company are required to be, co-borrowers In connection with the execution of the 2018 Loan Agreement, the Company issued warrants to purchase 30,173 shares of Series C convertible preferred stock. The estimated fair value of the warrants at issuance was recorded as a discount on the loan and is amortized to interest expense over the term of the agreement using the effective interest method. Amendments to the 2018 Loan Agreement In January 2019, the Company executed the First Amendment to the Loan and Security Agreement, which extended the interest-only period for all borrowings under the agreement until January 2020. No other terms were amended. In June 2019, the Company borrowed an additional $5.0 million to increase the total principal balance to $12.0 million. In connection with the June 2019 borrowing, the Company issued Silicon Valley Bank warrants to purchase 14,999 shares of Series C convertible preferred stock. In May 2020, the Company executed the Second Amendment to its Loan and Security Agreement, which deferred the principal payments due between May 2020 and July 2020 such that the deferred amounts will be repaid in equal monthly payments that started in August 2020 through the scheduled maturity of the loan in June 2022. The amendment was accounted for as a modification. In September 2020, the Company executed the Third Amendment to the Loan and Security Agreement (the “Third Amendment”), under which Silicon Valley Bank made available to the Company additional term loans in an aggregate principal amount of $20.0 million through December 31, 2020. The Company borrowed $15.0 million in September 2020 and used $10.2 million of the proceeds to repay the outstanding balance of $9.5 million and final payment fee of $0.7 million, or 6.0% of the original aggregate principal amount, on the existing term loan. The Company’s ability to borrow any additional principal under the Third Amendment expired unused on December 31, 2020. The term loan under the Third Amendment matures in September 2024 with interest-only monthly payments until January 2022, which was extended to July 2022 upon the completion of the Company’s IPO in October 2020. The term loan accrues interest at a per annum rate equal to the Wall Street Journal prime rate plus 1.0% (4.25% as of December 31, 2021) and includes a final payment fee equal to 6.25% of the original aggregate principal amount. In connection with the execution of the Third Amendment, the Company issued Silicon Valley Bank a warrant to purchase 53,487 shares of Series E convertible preferred stock. The amendment was accounted for as a modification. Borrowings under the Third Amendment are collateralized by substantially all the assets of the Company, excluding intellectual property (but including rights to payment and proceeds thereof). The Third Amendment contains customary affirmative and restrictive covenants, including with respect to the Company’s ability to enter into fundamental transactions, incur additional indebtedness, grant liens, pay any dividend or make any distributions to its holders, make investments, merge or consolidate with any other person or engage in transactions with the Company’s affiliates, but do not include any financial covenants. The Company was in compliance with all of the covenants as of December 31, 2021. During the years ended December 31, 2021, 2020 and 2019, the Company recognized interest expense related to the term loans of $1.1 million, $1.0 million and $0.7 million, respectively, which is inclusive of amortization of debt discount. The effective interest rate was 7.12% as of December 31, 2021. The balance of the term loans is as follows: December 31, 2021 2020 (in thousands) Principal value of long-term debt $ 15,000 $ 15,000 Net of debt discount and accretion of final payment 257 (163 ) Long-term debt, current and noncurrent 15,257 14,837 Less: Long-term debt, current portion (3,333 ) — Long-term debt, noncurrent portion $ 11,924 $ 14,837 Future minimum payments of principal and estimated payments of interest on the Company’s outstanding variable rate borrowings as of December 31, 2021 are as follows: Total (in thousands) 2022 $ 3,950 2023 7,038 2024 6,028 Total future payments 17,016 Less amounts representing interest (1,078 ) Less final payment (938 ) Total principal amount of term loan payments $ 15,000 Paycheck Protection Program loan On May 3, 2020, the Company executed a promissory note with MidFirst Bank, which provided for an unsecured loan in an aggregate principal amount of $4.6 million pursuant to the Paycheck Protection Program under the Coronavirus Aid, Relief and Economic Security Act signed into law on March 27, 2020 (the “PPP Loan”). In August 2020, the Company repaid the PPP Loan in full in the amount of $4.6 million and terminated the related promissory note. During the year ended December 31, 2020, the Company recognized interest expense related to the PPP Loan of less than $0.1 million. 2020 Convertible Promissory Notes The Company issued an aggregate of $8.9 million in convertible promissory notes in March 2020 and an additional aggregate of $1.2 million in April 2020 in a subsequent closing (the “2020 Notes”). The 2020 Notes accrued interest at a rate of 6.0% per annum. The 2020 Notes contained a redemption feature such that in the event of a qualified sale of preferred stock or other equity securities resulting in aggregate gross proceeds to the Company of at least $15.0 million, all principal and accrued and unpaid interest under the 2020 Notes will automatically convert into the preferred stock issued in such a financing at a price per share equal to 80% of the lowest price per share of the preferred stock sold in the financing. This redemption feature and other features contained in the 2020 Notes were determined to be embedded derivatives requiring bifurcation and were separately accounted for as a single compound derivative instrument. Upon the issuances of the 2020 Notes, the Company recorded the fair value of the derivative liability of $2.9 million as a debt discount on the 2020 Notes and as a single compound derivative instrument. The debt discount was being amortized to interest expense using the effective interest method over the term of the 2020 Notes. During the year ended December 31, 2020, the Company recognized interest expense related to the 2020 Notes of $0.9 million, which is inclusive of amortization of debt discount. In July 2020, the 2020 Notes were redeemed whereby the outstanding principal balance of $10.1 million and accrued interest of $0.2 million was converted into shares of Series E convertible preferred stock at a price equal to 80% of the amount per share paid by the investors in the Series E preferred stock financing. The redemption of the 2020 Notes was accounted for as a debt extinguishment, which resulted in a loss of $1.6 million that was recognized in other income (expense) in the consolidated statement of operations and comprehensive loss. The loss on extinguishment was calculated as the difference between (i) the fair value of the shares of Series E convertible preferred stock issued to settle the 2020 Notes and (ii) the carrying value of the 2020 Notes, net of the unamortized debt discount, plus the fair value of the derivative liability associated with the 2020 Notes at the time of extinguishment.

Convertible Preferred Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2021
Temporary Equity Disclosure [Abstract]
Convertible Preferred Stock	Note 9. Convertible preferred stock In July and August 2020, the Company issued an aggregate of 10,513,921 shares of Series E convertible preferred stock at a purchase price of $6.7836 per share in exchange for net proceeds of approximately $67.3 million. Contemporaneous with the initial closing of the Series E convertible preferred stock financing, the 2020 Notes (see Note 8) were redeemed whereby all of the outstanding principal and accrued interest amounting to $10.3 million was converted into 1,889,548 shares of Series E convertible preferred stock. In connection with the Series E convertible preferred stock financing, the Company amended and restated its certificate of incorporation. The amended and restated certificate of incorporation amended the liquidation right held by holders of Series C and Series C-1 This amendment of the liquidation right was determined to be significant using the qualitative approach. As such, the Company accounted for the amendment as an extinguishment of the outstanding Series C and Series C-1 C-1 C-1 C-1 In October 2020, immediately prior to the completion of the IPO, all of the then-outstanding shares of convertible preferred stock automatically converted into 28,196,388 shares of common stock at the applicable conversion ratio then in effect.

Stock-based Compensation

Stock-based Compensation	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-based Compensation	Note 10. Stock-based compensation Total stock-based compensation is as follows: Year ended December 31, 2021 2020 2019 (in thousands) Cost of revenue $ 738 $ 60 $ 16 Research and development 6,939 822 232 Sales and marketing 11,213 1,629 188 General and administrative 8,841 2,578 903 Total stock-based compensation $ 27,731 $ 5,089 $ 1,339 Stock-based compensation costs capitalized as part of capitalized software costs was $0.9 million and $0.2 million during the years ended December 31, 2021 and 2020. No such costs were capitalized during the years ended December 31, 2019. Equity incentive plans In November 2010, the Company adopted the 2010 Equity Incentive Plan (the “2010 Plan”) under which the Board had the authority to issue stock options to employees, directors and consultants. In October 2020, the Company’s board of directors and stockholders adopted and approved the 2020 Incentive Award Plan, (the “2020 Plan”) and 2020 Employee Stock Purchase Plan (the “ESPP”). The Company’s 2010 Plan was terminated in connection with the IPO and no further grants will be made under the 2010 Plan from the date that the 2020 Plan became effective. As of December 31, 2021, 5,106,223 shares of common stock are issuable upon the exercise of outstanding awards under the 2010 Plan. As of December 31, 2021, the Company had reserved 6,991,055 shares of common stock for issuance under the 2020 Plan, of which 6,244,669 are available for issuance in connection with grants of future awards. As a result of the uncertainty created by the DOJ investigation and the claims audits, the Company suspended its practice of granting equity awards to new hires, except for new restricted stock unit grants that the Company has the option to settle in cash at the time of vesting, suspended its ESPP and deferred the settlement of outstanding RSUs, each effective as of November 9, 2021. The Board of Directors also determined to suspend the non-employee non-employee Stock options Stock option activity for the year ended December 31, 2021 is set forth below: Number of shares Weighted average exercise price Weighted average remaining contractual term Aggregate intrinsic value (in years) (in thousands) Balance December 31, 2020 6,468,844 $ 2.78 8.77 $ 271,944 Grants 323,105 46.97 Exercises (859,200 ) 2.01 Cancelled/forfeited (525,934 ) 9.68 Balance December 31, 2021 5,406,815 $ 4.87 7.88 $ 12,860 Vested and exercisable at December 31, 2021 2,377,275 $ 3.21 7.18 $ 6,585 The weighted-average grant-date fair value of options granted during the years ended December 31, 2021, 2020 and 2019 were $24.72, $3.22 and $2.85 per share, respectively. The aggregate intrinsic values of options outstanding and vested and exercisable were calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock. The intrinsic value of options exercised during the years ended December 31, 2021 and 2020 was $32.4 million and $5.0 million, respectively, and was immaterial during the year ended December 31, 2019. As of December 31, 2021, total unrecognized stock-based compensation related to outstanding unvested stock options was $13.2 million, which the Company expects to recognize over a remaining weighted-average period of 2.4 years. The estimated grant-date fair value of the Company’s stock options was calculated using the Black-Scholes option pricing model, based on the following assumptions: Year ended December 31, Valuation assumptions: 2021 2020 2019 Expected volatility 53%-57% 60%-71% 58%-60% Expected term 5.8-6.7 years 5.1-7.0 years 5.0-10.0 years Risk-free interest rate 0.62%- 0.23%- 1.46%-2.51% Dividend yield — — — Restricted stock units Restricted stock units (“RSUs”) granted under the 2020 Plan are share awards that generally entitle the holder to receive freely tradable shares of the Company’s common stock upon vesting. However, the Company has deferred the settlement of outstanding RSUs effective November 9, 2021. The RSUs cannot be transferred and the awards are subject to forfeiture if the holder’s service to the Company terminates prior to the release of the vesting restrictions. RSU activity for the year ended December 31, 2021 is set forth below: Number of shares Weighted grant date fair per share Unvested as of December 31, 2020 8,270 $ 50.70 RSUs granted 509,860 43.40 RSUs vested (43,859 ) 52.34 RSUs forfeited (125,820 ) 41.36 Unvested as of December 31, 2021 348,451 $ 43.19 As of December 31, 2021, there were 17,310 RSUs outstanding that had vested but not settled, which were subsequently settled for $0.1 million in cash in March 2022. As of December 31, 2021, there was $13.9 million of total unrecognized compensation cost related to the RSUs that is expected to be recognized over a weighted-average period of 3.4 years. Performance-based restricted stock units In June 2021, the Company granted 80,000 RSUs with performance-based vesting conditions primarily related to sales targets that must be met by December 31, 2022 for the awards to vest. The vesting conditions were deemed probable as of December 31, 2021. The grant date fair value of the awards was $3.0 million. None of these awards have vested or were forfeited as of December 31, 2021. Employee stock purchase plan As of December 31, 2021, the Company reserved 1,109,239 shares of common stock for issuance under the ESPP, of which 934,496 are available for future issuance. The ESPP provides for consecutive, overlapping 24-month Each offering period consists of four six-month Subsequent to the suspension of the ESPP on November 9, 2021, all outstanding participant contribution amounts of $2.2 million were refunded to participants during the fourth quarter of 2021 and all future purchases under the current offering periods were cancelled. The Company accounted for the suspension of the ESPP as a cancellation of the ESPP and recognized $9.0 million of stock-based compensation in the fourth quarter of 2021 primarily as a result of the suspension. The Company recorded an aggregate of $17.4 million of stock-based compensation related to the ESPP for the year ended December 31, 2021, which includes the amounts recorded upon the suspension of the ESPP. The fair value of the ESPP shares is estimated using the Black-Scholes option pricing model, based on the following assumptions for the offering period that started in May 2021: Valuation assumptions: Year ended December 31, Expected volatility 44%-57% Expected term 0.5-2.0 years Risk-free interest rate 0.04%-0.16% Dividend yield —

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 11. Income taxes The Company has not recorded an income tax provision for the years ended December 31, 2021, 2020 and 2019 due to its history of operating losses. All loss before income taxes was generated in the United States for the years ended December 31, 2021, 2020 and 2019. Reconciliation of the statutory federal income tax to the Company’s effective tax is as follows: December 31, 2021 2020 2019 (in thousands) Income tax provision at statutory rate $ (33,128 ) $ (8,370 ) $ (9,342 ) State income taxes, net of federal benefit (3,104 ) (826 ) (2,350 ) Change in valuation allowance 37,792 8,720 3,064 Stock-based compensation (716 ) (621 ) 190 Section 382 limitation on net operating loss and credit carryforwards — — 9,956 Research and development tax credits (1,210 ) (1,442 ) (1,306 ) Change in fair value of warrants 21 326 79 Derivative liability and extinguishment of debt — 545 — Return-to-provision 308 1,261 (413 ) Other 37 407 122 Total current income tax provision $ — $ — $ — The tax effects of temporary differences and carryforwards that give rise to significant portions of deferred tax assets are as follows: December 31, 2021 2020 2019 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 62,322 $ 35,943 $ 29,684 Depreciation and amortization — — — Research and development credits 5,120 3,910 2,468 Accruals and reserves 13,597 2,986 1,667 Lease liability 1,690 — — Stock-based compensation 565 589 345 Total deferred tax assets 83,294 43,428 34,164 Valuation allowance (80,226 ) (42,435 ) (33,714 ) Deferred tax assets after valuation allowance 3,068 993 450 Deferred tax liabilities: Depreciation and amortization (1,429 ) (993 ) (450 ) Right-of-use (1,639 ) — — Total deferred tax liabilities (3,068 ) (993 ) (450 ) Net deferred tax assets $ — $ — $ — Due to the uncertainties surrounding the realization of deferred assets through future income, the Company has established a full valuation allowance against its deferred tax assets and, therefore, no benefit has been recognized for the net operating loss and other deferred tax assets. The valuation allowance increased by $37.8 million, $8.7 million and $3.1 million during the years ending December 31, 2021, 2020 and 2019. As of December 31, 2021, the Company had federal net operating loss carryforwards of approximately $252.6 million, of which $32.6 million begin to expire in the year 2030 and $220.0 million will carry over indefinitely. The Company also has state net operating loss carryovers of approximately $112.6 million available to reduce future taxable income, if any. The state carryforwards begin to expire beginning in the year 2030. As of December 31, 2021, the Company had research and development credits carryovers for federal income tax purposes of approximately $3.6 million which expire beginning in the year 2031. The Company also has state research and development credit carryforwards of approximately $3.8 million as of December 31, 2021, which do not expire. Utilization of the net operating loss and credit carryforwards will be subject to an annual limitation due to the ownership percentage change limitations provided by the Internal Revenue Code of 1986, as amended, and similar state provisions. The annual limitation may result in the expiration of the net operating loss carryforwards before utilization. In the event the Company has had a change of ownership, utilization of the carryforwards could be restricted. The Company’s net operating loss deferred tax asset was reduced from the prior year as a result of limitation on the utilization of net operating loss carryforwards subject to the Internal Revenue Code Section 382. Uncertain tax positions A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: December 31, 2021 2020 2019 (in thousands) Beginning balance $ 1,676 $ 1,058 $ 576 Increases related to current year tax positions 518 618 482 Ending balance $ 2,194 $ 1,676 $ 1,058 If recognized, gross unrecognized tax benefits would not have an impact on the Company’s effective tax rate due to the Company’s full valuation allowance position. While it is often difficult to predict the final outcome of any particular uncertain tax position, the Company does not believe that the amount of gross unrecognized tax benefits will change significantly in the next twelve months. The Company’s income tax returns for all tax years remain open to examination by federal and state taxing authorities due to the taxing authorities’ ability to adjust operating loss carryforwards. The Company has elected to recognize interest and penalties related to uncertain tax positions as a component of the income tax provision. No such expenses were incurred in the years ended December 31, 2021, 2020 and 2019. The Company has not made any accruals for payment of interest related to unrecognized tax benefits.

Net Loss Per Share Attributable

Net Loss Per Share Attributable To Common Stockholders	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Loss Per Share Attributable To Common Stockholders	Note 12. Net loss per share attributable to common stockholders The following outstanding potentially dilutive common stock equivalents have been excluded from the computation of diluted net loss per share for the periods presented due to their anti-dilutive effect: Year ended December 31, 2021 2020 2019 Convertible preferred stock — — 13,710,242 Common stock options issued and outstanding 5,406,815 6,468,844 3,474,052 Restricted stock units 428,451 8,270 — Shares issuable pursuant to ESPP — 17,865 — Convertible preferred stock warrants — — 73,913 Total 5,835,266 6,494,979 17,258,207 The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders: Year ended December 31, 2021 2020 2019 (in thousands, except share and per share Numerator: Net loss $ (157,754 ) $ (39,855 ) $ (44,486 ) Gain on extinguishment of Series C and Series C-1 — 9,840 — Net loss attributable to common stockholders, basic and diluted $ (157,754 ) $ (30,015 ) $ (44,486 ) Denominator: Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 38,899,457 7,890,375 256,452 Net loss per share attributable to common stockholders, basic and diluted $ (4.06 ) $ (3.80 ) $ (173.47 )

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 13. Subsequent events Settlement of DOJ investigation On April 29, 2022, the Company entered into a civil settlement agreement with the U.S. government that resolved the DOJ investigation related to the Company’s role in customer reimbursement claim submissions to various federal employee health plans under the FEHB program. As of December 31, 2021, the Company recorded a million settlement liability in connection with the settlement. On May 2, 2022, the Company paid the settlement amount.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of presentation and principles of consolidation The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The consolidated financial statements include the accounts of Eargo, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated.
Use of Estimates	Use of estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions, and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates and assumptions made in the accompanying consolidated financial statements include, but are not limited to, the sales returns reserve, the present value of lease liabilities, the fair value of equity securities, the fair value of financial instruments, the allowance for credit losses, the net realizable value of inventory, the fair value of assets acquired in a business combination, the useful lives of long-lived assets, accrued product warranty reserve, legal and other contingencies, certain other accruals and recoverability of the Company’s net deferred tax assets and the related valuation allowance. Management periodically evaluates its estimates, which are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates.
Cash and cash equivalents	Cash and cash equivalents Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less from the purchase date. Cash equivalents consist primarily of amounts invested in money market accounts.
Concentration of Credit Risk	Concentration of credit risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of demand deposit accounts, money market accounts and accounts receivable, including credit card receivables. The Company maintains its cash and cash equivalents, which may, at times, exceed federally insured limits, with financial institutions of high credit standing. As of December 31, 2021, the Company has not experienced any losses on its deposit accounts and money market accounts. As of December 31, 2021, the Company does not believe there is significant financial risk from nonperformance by the issuers of the Company’s deposit accounts and money market accounts. Approximately 93% and 74% of the Company’s gross accounts receivable as of December 31, 2021 and 2020, respectively, were for customers with insurance benefits, substantially all of whom were covered under the FEHB program. Furthermore, approximately 90% and 45% of the Company’s gross accounts receivable as of December 31, 2021 and 2020, respectively, were related to shipments of Eargo hearing aids to customers insured under a single insurance plan whose claims are processed through the Company’s largest third-party payor, which conducted the Primary Audit. The increase in gross accounts receivable as of December 31, 2021 was primarily due to the Primary Audit, during which certain claims with a service date after March 1, 2021 have not yet and may never be submitted for reimbursement. We remain subject to a prepayment review of claims by the payor who conducted the Primary Audit. Please see caption “DOJ investigation and settlement and claims audits” in Note 1
Fair Value Measurement	Fair value measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. The Company measures fair value based on a three-level hierarchy of inputs, of which the first two are considered observable and the last unobservable. Unobservable inputs reflect the Company’s own assumptions about current market conditions. The Company maximizes the use of observable inputs, where available, and minimizes the use of unobservable inputs when measuring fair value. The three-level hierarchy of inputs is as follows: Level Level Level To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the consolidated balance sheets for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The fair value of the Company’s outstanding term loan is estimated using the net present value of the payments, discounted at an interest rate that is consistent with a market interest rate, which is a Level 2 input. The fair value of the outstanding term loan approximates the carrying amount as the term loan bears a floating rate that approximates the market interest rate. Refer to Note 3 for discussion of certain other financial instruments.
Accounts Receivable, Net	Accounts receivable, net Accounts receivable represents amounts due from third-party institutions for credit card and debit card transactions and trade accounts receivable. Trade accounts receivable are primarily insurance claims receivable amounts due from customers, which includes third-party payors and end-users. The Company adopted Accounting Standards Codification (“ASC”) Topic 326, Financial Instruments—Credit Losses effective January 1, 2021
Inventories	Inventories Inventories are stated at the lower of standard cost (which approximates actual cost on a first-in, first-out
Property and Equipment, Net	Property and equipment, net Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization on property and equipment is calculated using the straight-line method over the estimated useful lives of the assets, generally three
Capitalized Software Development Costs	Capitalized software development costs The Company capitalizes software purchased for internal use and qualified costs incurred in connection with the development of internal use software. Purchased software consists of software products and licenses, which are amortized over the lesser of their estimated useful life or the contractual term. Internally developed software costs incurred in the preliminary stages of development are expensed as incurred. Once an application has reached the development stage, internal and external direct costs of the development are capitalized until the software is substantially complete and ready for its intended use. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable that the expenditure will result in additional functionality. Internal use software is amortized on a straight-line basis over its estimated useful life, generally three years. Post-implementation activities including training and maintenance are expensed as incurred. Capitalized costs less accumulated amortization are recorded as a component of property and equipment, net on the consolidated balance sheets.
Goodwill, Finite-Lived Acquired Intangible Assets, and Impairment	Goodwill, finite-lived acquired intangible assets, and impairment Goodwill represents the excess of the purchase price paid over the fair value of tangible and identifiable intangible net assets acquired in business combinations. In November of each fiscal year, or more frequently if indicators of impairment exist, management performs a review to determine if the carrying value of goodwill is impaired. Impairment testing is performed at the reporting unit level. The Company’s intangible assets consist of intangible assets acquired in a business combination. These assets are amortized using the straight-line method over their estimated useful lives ranging from on The Company evaluates its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or group of assets may not be fully recoverable. Recoverability is measured by comparing the carrying amount to the future net undiscounted cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the projected discounted future net cash flows arising from the asset.
Leases	Leases The Company adopted ASC Topic 842 Leases Leases right-of-use ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized based on the present value of lease payments over the lease term at the commencement date of the lease. ROU assets also include any initial direct costs incurred and any lease payments made at or before the lease commencement date, less any lease incentive received. As the Company’s leases do not provide an implicit interest rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease expense is recognized on a straight-line basis over the lease term.
Product Warranty	Product warranty The Company provides a one-year two-year
Convertible Preferred Stock Warrant Liability	Convertible preferred stock warrant liability The Company accounts for its convertible preferred stock warrants issued in connection with its various financing transactions based upon the characteristics and provisions of the instrument. Convertible preferred stock warrants classified as liabilities are recorded on the consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value at each reporting period, with the changes in fair value recognized as other income (expense), net in the consolidated statements of operations and comprehensive loss. The Company adjusted the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants were no longer considered liability instruments. Upon the closing of the IPO in October 2020
Derivative Liability	Derivative liability The Company’s convertible notes issued in 2020 (the “2020 Notes”) contain certain features that meet the definition of embedded derivatives requiring bifurcation from the 2020 Notes as a separate compound financial instrument. The derivative liability is initially measured at fair value on issuance and is subject to remeasurement at each reporting period with changes in fair value recognized in other income (expense), net in the consolidated statements of operations and comprehensive loss. In July 2020, the derivative liability was settled upon the extinguishment of the 2020 Notes. Refer to Note 3 and Note 8 for further discussion.
Revenue Recognition	Revenue recognition The Company’s revenue is generated from the sale of products (hearing aid systems and related accessories) and services (extended warranties). These products and services are primarily sold directly to customers through the Eargo website and the Company’s sales representatives. Under ASC 606, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services by following a five step process: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. Identify the contract with a customer Identify the performance obligations in the contract one-time i.e. The Company has elected to treat shipping and handling activities performed after a customer obtains control of products as a fulfillment activity. Determine the transaction price and allocation to performance obligations 45-day method of direct payment). Please see caption “DOJ investigation and settlement and claims audits” in Note 1 for more information regarding the extended right of return. To estimate product returns, the Company analyzes various factors, including historical return levels, current economic trends, and insurance coverage. Based on this information, the Company reserves a percentage of product sale revenue and accounts for the estimated impact as a reduction in the transaction price. Consideration paid or payable to a customer that is not for a distinct good or service is accounted for as a reduction of the transaction price and recorded as a reduction in revenue in the period it becomes payable. Allocate the transaction price to the performance obligations in the contract. Recognize revenue when or as the Company satisfies a performance obligation Contract costs The Company applies the practical expedient to recognize the incremental costs of obtaining a contract as expense when incurred if the amortization period would be one year or less. These incremental costs include processing fees paid to third-party financing vendors, who provide the Company’s customers with the option to finance their purchases. If a customer elects to utilize this service, the Company receives a non-recourse
Cost of Revenue	Cost of revenue Cost of revenue consists of expenses relating to the cost of finished goods, freight, personnel costs, consumables, product warranty costs, transaction fees including processing fees paid to third-party financing vendors, transaction fees, reserves for excess and obsolete inventory, depreciation and amortization, and related overhead.
Research and Development	Research and development Research and development expenses consist of personnel costs, travel expenses, tools, prototype materials and product certification and are charged to expense as incurred.
Sales and Marketing	Sales and marketing Sales and marketing expenses consist of personnel costs, travel expenses, consulting fees, public relations costs, direct marketing, advertising and promotional expenses and allocated facility overhead costs. The Company recorded advertising costs, which are expensed as incurred, of $41.9 million, $23.6 million and $18.6 million for the years ended December 31, 2021, 2020 and 2019, respectively.
Stock-based Compensation	Stock-based compensation The Company accounts for stock-based awards at fair value. The fair value of restricted stock units (“RSUs”) is equal to the closing price of the Company’s common stock on the grant date. The fair value of stock options and purchase rights under an employee stock purchase plan are estimated on the date of grant using the Black-Scholes option-pricing model. The fair value of the underlying common stock is the closing price of the Company’s common stock for grants subsequent to the Company’s IPO. The expected volatility is derived from the historical stock volatilities of comparable peer public companies within the Company’s industry that are considered to be comparable to the Company’s business over a period equivalent to the expected term of the awards due to limited trading history of the Company’s common stock. The expected term for employee option grants is determined using the simplified method due to a lack of sufficient data points. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The expected dividend yield is zero as the Company has not paid nor does it anticipate paying any dividends on its common stock in the foreseeable future. For stock-based awards that vest subject to the satisfaction of a service requirement, the fair value measurement date is the date of grant and the expense is recognized on a straight-line basis over the requisite service period. For stock-based awards with performance-based vesting conditions, the expense is recognized over the vesting period using the accelerated attribution method. The Company accounts for forfeitures as they occur.
Income Taxes	Income taxes The Company uses the asset and liability method to account for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized. Financial statement effects of uncertain tax positions are recognized when it is more-likely-than-not
Segments	Segments Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its Chief Executive Officer. To date, the Company has viewed its operations and manages its business as one operating and reportable segment, with all operations in the United States.
Employee Benefit Plan	Employee benefit plan The Company sponsors a qualified 401(k) defined contribution plan covering eligible employees. Participants may contribute a portion of their annual compensation limited to a maximum annual amount set by the Internal Revenue Service. There have been no employer contributions under this plan to date.
Net Loss per Share Attributable To Common Stockholders	Net loss per share attributable to common stockholders The Company follows the two-class two-class two-class Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration for potential dilutive securities. Diluted net loss attributable to common stockholders is computed by adjusting net loss attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and common share equivalents of potentially dilutive securities outstanding for the period. Potentially dilutive securities are not assumed to have been issued if their effect is anti- dilutive
Emerging Growth Company Status	Emerging growth company status The Company ceased to be an emerging growth company (“EGC”) on December 31, 2021 because the aggregate worldwide market value of the voting and non-voting non-affiliates
Recently Adopted and Recent Accounting Pronouncements Not Yet Adopted	Recently adopted accounting pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments January 1, 2021 Recent accounting pronouncements not yet adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes In August 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) 815-40) 470-20

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Embedded Derivatives
Summary of Change in Estimated Fair Value of Derivative Liability	The following table provides a summary of the change in the estimated fair value of the Company’s derivative liability: Total Balance—December 31, 2019 $ — Initial fair value of derivative liability 2,879 Change in fair value of derivative liability 206 Extinguishment of derivative liability (3,085 ) Balance—December 31, 2020 $ —
Convertible Preferred Stock Warrant Liability
Summary of Change in Estimated Fair Value of Convertible Preferred Stock Warrant Liability	The following table provides a summary of the change in the estimated fair value of the Company’s convertible preferred stock warrant liability: Total Balance—December 31, 2019 396 Fair value of convertible preferred stock warrants issued in connection with debt financing 270 Change in fair value of warrant liability 1,265 Conversion of preferred stock warrants to common stock warrants upon the closing of the IPO (1,931 ) Balance—December 31, 2020 $ —
Summary of Fair Value of Convertible Preferred Stock Warrants Converted to Common Stock Warrants upon Closing of IPO Determined Using Following Assumptions	The fair value of the convertible preferred stock warrants, which were converted to common stock warrants upon the closing of the IPO in October 2020, was determined using the following assumptions: Valuation assumptions: December 31, Expected volatility 67%-71% Expected term 2.17-9.9 years Risk-free interest rate 0.15%-0.75% Dividend yield —

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Inventories	Inventories consist primarily of raw materials related to component parts and finished goods. The following is a summary of the Company’s inventories by category: December 31, 2021 2020 (in thousands) Raw materials $ 1,905 $ 853 Finished goods 3,807 1,886 Total inventories $ 5,712 $ 2,739
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following: December 31, 2021 2020 (in thousands) Advanced payroll deposits $ 3,889 $ — Prepaid insurance fees 2,945 1,931 Prepaid marketing costs 1,948 245 Prepaid software subscription 1,468 995 Other 623 569 Total prepaid expenses and other current assets $ 10,873 $ 3,740
Summary of Property And Equipment, Net	Property and equipment, net, consists of the following: December 31, 2021 2020 (in thousands) Capitalized software $ 11,569 $ 6,744 Tools and lab equipment 4,712 4,426 Furniture and fixtures 906 906 Leasehold improvements 861 757 Computer and equipment 401 288 18,449 13,121 Less accumulated depreciation and amortization (8,898 ) (5,087 ) Total property and equipment, net $ 9,551 $ 8,034
Summary of Accrued Expenses	Accrued expenses consist of the following: December 31, 2021 2020 (in thousands) Accrued compensation $ 4,845 $ 5,861 Accrued warranty reserve 4,014 2,390 Refunds due to customers 376 581 Accrued vendor costs — 751 Total accrued expenses $ 9,235 $ 9,583
Summary of Sales Returns Reserve	The sales returns reserve consists of the following activity: Year ended December 31, 2021 2020 2019 (in thousands) Sales returns reserve, beginning balance $ 4,326 $ 3,759 $ 2,713 Reduction of revenue 37,674 22,676 17,739 Utilization of sales returns reserve (28,172 ) (22,109 ) (16,693 ) Sales returns reserve, ending balance $ 13,828 $ 4,326 $ 3,759
Summary of Allowance for Credit Losses	The allowance for credit losses consists of the following activity: Year ended December 31, 2021 2020 2019 (in thousands) Allowance for credit losses, beginning balance $ 1,868 $ 225 $ — Charged to expense 9,615 2,352 225 Accounts written off, net of recoveries (6,645 ) (709 ) — Allowance for credit losses, ending balance $ 4,838 $ 1,868 $ 225
Summary of Accrued Warranty Reserve	The accrued warranty reserve consists of the following activity: Year ended December 31, 2021 2020 2019 (in thousands) Accrued warranty reserve, beginning balance $ 2,390 $ 450 $ 53 Charged to cost of revenue 3,229 3,178 1,589 Utilization of accrued warranty reserve (1,605 ) (1,238 ) (1,192 ) Accrued warranty reserve, ending balance $ 4,014 $ 2,390 $ 450

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Summary of Preliminary Purchase Price Allocation for Acquisition	The table below presents the purchase price allocation: (in thousands) Goodwill $ 873 Intangible assets 1,990 Total fair value of consideration $ 2,863

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Undiscounted Future Minimum Lease Payments Due under Non-cancelable Operating Leases	As of December 31, 2021, undiscounted future minimum lease payments due under the non-cancelable Operating leases (in thousands) 2022 $ 1,327 2023 1,114 2024 1,081 2025 1,331 2026 1,372 Thereafter 3,607 Total minimum future lease payments 9,832 Present value adjustment for minimum lease commitments (2,442 ) Total lease liability $ 7,390

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill are as follows: Total (in thousands) Balance December 31, 2020 $ — Addition due to business acquisition 873 Balance December 31, 2021 $ 873
Summary of Intangible Assets, Net	Intangible assets, net consist of the following as of December 31, 2021: Gross Accumulated Net carrying (in thousands) Developed technologies $ 1,700 $ 212 $ 1,488 Other 290 97 193 Total intangible assets, net $ 1,990 $ 309 $ 1,681
Summary of Estimated Future Amortization Expense of Finite-lived Intangible Assets, Net	The following table summarizes estimated future amortization expense of finite-lived intangible assets, net as of December 31, 2021: Amount (in thousands) 2022 $ 618 2023 425 2024 425 2025 213 Total $ 1,681

Debt Obligations (Tables)

Debt Obligations (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Balance of Term Loan	The balance of the term loans is as follows: December 31, 2021 2020 (in thousands) Principal value of long-term debt $ 15,000 $ 15,000 Net of debt discount and accretion of final payment 257 (163 ) Long-term debt, current and noncurrent 15,257 14,837 Less: Long-term debt, current portion (3,333 ) — Long-term debt, noncurrent portion $ 11,924 $ 14,837
Schedule of Future Minimum Payments	Future minimum payments of principal and estimated payments of interest on the Company’s outstanding variable rate borrowings as of December 31, 2021 are as follows: Total (in thousands) 2022 $ 3,950 2023 7,038 2024 6,028 Total future payments 17,016 Less amounts representing interest (1,078 ) Less final payment (938 ) Total principal amount of term loan payments $ 15,000

Stock-based Compensation (Table

Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of Total Stock-based Compensation	Total stock-based compensation is as follows: Year ended December 31, 2021 2020 2019 (in thousands) Cost of revenue $ 738 $ 60 $ 16 Research and development 6,939 822 232 Sales and marketing 11,213 1,629 188 General and administrative 8,841 2,578 903 Total stock-based compensation $ 27,731 $ 5,089 $ 1,339
Summary of Stock Option Activity	Stock option activity for the year ended December 31, 2021 is set forth below: Number of shares Weighted average exercise price Weighted average remaining contractual term Aggregate intrinsic value (in years) (in thousands) Balance December 31, 2020 6,468,844 $ 2.78 8.77 $ 271,944 Grants 323,105 46.97 Exercises (859,200 ) 2.01 Cancelled/forfeited (525,934 ) 9.68 Balance December 31, 2021 5,406,815 $ 4.87 7.88 $ 12,860 Vested and exercisable at December 31, 2021 2,377,275 $ 3.21 7.18 $ 6,585
Assumptions used in Estimating Grant-Date Fair Value of Stock-based Awards Using Black-Scholes Option Pricing Model	The estimated grant-date fair value of the Company’s stock options was calculated using the Black-Scholes option pricing model, based on the following assumptions: Year ended December 31, Valuation assumptions: 2021 2020 2019 Expected volatility 53%-57% 60%-71% 58%-60% Expected term 5.8-6.7 years 5.1-7.0 years 5.0-10.0 years Risk-free interest rate 0.62%- 0.23%- 1.46%-2.51% Dividend yield — — —
Schedule of RSU Activity	RSU activity for the year ended December 31, 2021 is set forth below: Number of shares Weighted grant date fair per share Unvested as of December 31, 2020 8,270 $ 50.70 RSUs granted 509,860 43.40 RSUs vested (43,859 ) 52.34 RSUs forfeited (125,820 ) 41.36 Unvested as of December 31, 2021 348,451 $ 43.19
Fair Value of ESPP Shares Estimated Using Black-Scholes Option Pricing Model	The fair value of the ESPP shares is estimated using the Black-Scholes option pricing model, based on the following assumptions for the offering period that started in May 2021: Valuation assumptions: Year ended December 31, Expected volatility 44%-57% Expected term 0.5-2.0 years Risk-free interest rate 0.04%-0.16% Dividend yield —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Statutory Federal Income Tax to Effective Tax	Reconciliation of the statutory federal income tax to the Company’s effective tax is as follows: December 31, 2021 2020 2019 (in thousands) Income tax provision at statutory rate $ (33,128 ) $ (8,370 ) $ (9,342 ) State income taxes, net of federal benefit (3,104 ) (826 ) (2,350 ) Change in valuation allowance 37,792 8,720 3,064 Stock-based compensation (716 ) (621 ) 190 Section 382 limitation on net operating loss and credit carryforwards — — 9,956 Research and development tax credits (1,210 ) (1,442 ) (1,306 ) Change in fair value of warrants 21 326 79 Derivative liability and extinguishment of debt — 545 — Return-to-provision 308 1,261 (413 ) Other 37 407 122 Total current income tax provision $ — $ — $ —
Schedule of Tax Effects of Temporary Differences and Carryforwards of Significant Portions of Deferred Tax Assets	The tax effects of temporary differences and carryforwards that give rise to significant portions of deferred tax assets are as follows: December 31, 2021 2020 2019 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 62,322 $ 35,943 $ 29,684 Depreciation and amortization — — — Research and development credits 5,120 3,910 2,468 Accruals and reserves 13,597 2,986 1,667 Lease liability 1,690 — — Stock-based compensation 565 589 345 Total deferred tax assets 83,294 43,428 34,164 Valuation allowance (80,226 ) (42,435 ) (33,714 ) Deferred tax assets after valuation allowance 3,068 993 450 Deferred tax liabilities: Depreciation and amortization (1,429 ) (993 ) (450 ) Right-of-use (1,639 ) — — Total deferred tax liabilities (3,068 ) (993 ) (450 ) Net deferred tax assets $ — $ — $ —
Schedule of Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows: December 31, 2021 2020 2019 (in thousands) Beginning balance $ 1,676 $ 1,058 $ 576 Increases related to current year tax positions 518 618 482 Ending balance $ 2,194 $ 1,676 $ 1,058

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable To Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Summary of Outstanding Potentially Dilutive Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share	The following outstanding potentially dilutive common stock equivalents have been excluded from the computation of diluted net loss per share for the periods presented due to their anti-dilutive effect: Year ended December 31, 2021 2020 2019 Convertible preferred stock — — 13,710,242 Common stock options issued and outstanding 5,406,815 6,468,844 3,474,052 Restricted stock units 428,451 8,270 — Shares issuable pursuant to ESPP — 17,865 — Convertible preferred stock warrants — — 73,913 Total 5,835,266 6,494,979 17,258,207
Computation of Basic And Diluted Net Loss Per Share Attributable to Common Stockholders	The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders: Year ended December 31, 2021 2020 2019 (in thousands, except share and per share Numerator: Net loss $ (157,754 ) $ (39,855 ) $ (44,486 ) Gain on extinguishment of Series C and Series C-1 — 9,840 — Net loss attributable to common stockholders, basic and diluted $ (157,754 ) $ (30,015 ) $ (44,486 ) Denominator: Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 38,899,457 7,890,375 256,452 Net loss per share attributable to common stockholders, basic and diluted $ (4.06 ) $ (3.80 ) $ (173.47 )

Description of Business and O_2

Description of Business and Other Matters - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Apr. 29, 2022	Mar. 31, 2021	Dec. 31, 2020
Description Of Business [Line Items]
Cash and cash equivalents	$ 110,500			$ 212,185
Accumulated deficit	356,812			199,058
Settlement Liability	34,372	$ 34,400		0
Sales returns reserve	13,827		$ 13,300	$ 4,326
Bad debt expense	9,600
Bad debt write off	5,800
Accounts Receivable [Member]
Description Of Business [Line Items]
Sales returns reserve	11,400
FEHB program [Member]
Description Of Business [Line Items]
Sales returns reserve	$ 44,000

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)segment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Summary Of Significant Accounting Policies [Line Items]
Product warranty limited warranty period	1 year
Advertising costs | $	$ 41,900	$ 23,600	$ 18,600
Number of operating segment | segment	1
Number of reportable segment | segment	1
Employee benefit plan, employer contributions | $	$ 0
Change in accounting principle, accounting standards update, adopted	true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true
ASU 2016-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Internal Use Software
Summary Of Significant Accounting Policies [Line Items]
Finite-lived intangible asset, useful life	3 years
Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment	3 years
Finite-lived intangible asset, useful life	1 year
Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment	5 years
Finite-lived intangible asset, useful life	4 years
Accounts Receivable | Credit Concentration Risk | FEHB
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	93.00%	74.00%
Accounts Receivable | Credit Concentration Risk | Eargo Hearing Aids
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	90.00%	45.00%

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Millions	Dec. 31, 2021USD ($)
Fair Value Disclosures [Abstract]
Financial assets outstanding	$ 0
Financial liabilities outstanding	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Change in Estimated Fair Value of Convertible Preferred Stock Warrant Liability (Details) - Convertible Preferred Stock Warrant Liability $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance	$ 396
Fair value of convertible preferred stock warrants issued in connection with debt financing	270
Change in fair value of warrant liability	1,265
Conversion of preferred stock warrants to common stock warrants upon the closing of the IPO	(1,931)
Balance	$ 0

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Fair Value of Convertible Preferred Stock Warrants Converted to Common Stock Warrants upon Closing of IPO Determined Using Following Assumptions (Details) - Convertible Preferred Stock Warrant Liability	Dec. 31, 2020
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Expected term	2 years 2 months 1 day
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Expected term	9 years 10 months 24 days
Expected Volatility | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	67
Expected Volatility | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	71
Risk-Free Interest Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.15
Risk-Free Interest Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.75
Dividend Yield
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Change in Estimated Fair Value of Derivative Liability (Details) - Embedded Derivatives $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance — December 31, 2019	$ 0
Initial fair value of derivative liability	2,879
Change in fair value of derivative liability	206
Extinguishment of derivative liability	(3,085)
Balance — December 31, 2020	$ 0

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 1,905	$ 853
Finished goods	3,807	1,886
Total inventories	$ 5,712	$ 2,739

Balance Sheet Components - Su_2

Balance Sheet Components - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Advanced payroll deposits	$ 3,889	$ 0
Prepaid insurance fees	2,945	1,931
Prepaid marketing costs	1,948	245
Prepaid software subscription	1,468	995
Other	623	569
Total prepaid expenses and other current assets	$ 10,873	$ 3,740

Balance Sheet Components - Su_3

Balance Sheet Components - Summary of Property And Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 18,449	$ 13,121
Less accumulated depreciation and amortization	(8,898)	(5,087)
Total property and equipment, net	9,551	8,034
Capitalized Software
Property Plant And Equipment [Line Items]
Total property and equipment, gross	11,569	6,744
Tools and Lab Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	4,712	4,426
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment, gross	906	906
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	861	757
Computer and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 401	$ 288

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2021
Depreciation and amortization expense		$ 4,202	$ 2,525	$ 1,528
Amortization of capitalized software costs		2,100	800	300
Reduction in revenue	$ 13,300	37,674	22,676	17,739
Bad debt expense		9,615	2,352	$ 225
Bad debt write off		5,800
Sales returns reserve		13,827	$ 4,326		$ 13,300
Accounts Receivable [Member]
Sales returns reserve		$ 11,400

Balance Sheet Components - Su_4

Balance Sheet Components - Summary of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued compensation	$ 4,845	$ 5,861
Accrued warranty reserve	4,014	2,390
Refunds due to customers	376	581
Accrued vendor costs	0	751
Total accrued expenses	$ 9,235	$ 9,583

Balance Sheet Components - Su_5

Balance Sheet Components - Summary of Allowance for Sales Returns (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Sales returns reserve, beginning balance	$ 4,326	$ 4,326	$ 3,759	$ 2,713
Reduction to revenue	$ 13,300	37,674	22,676	17,739
Utilization of sales returns reserve		(28,172)	(22,109)	(16,693)
Sales returns reserve, ending balance		$ 13,828	$ 4,326	$ 3,759

Balance Sheet Components - Su_6

Balance Sheet Components - Summary of Allowance for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Allowance for credit losses, beginning balance	$ 1,868	$ 225	$ 0
Charged to expense	9,615	2,352	225
Accounts written off, net of recoveries	(6,645)	(709)	0
Allowance for credit losses, ending balance	$ 4,838	$ 1,868	$ 225

Balance Sheet Components - Su_7

Balance Sheet Components - Summary of Accrued Warranty Reserve (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued warranty reserve, beginning balance	$ 2,390	$ 450	$ 53
Charged to cost of revenue	3,229	3,178	1,589
Utilization of accrued warranty reserve	(1,605)	(1,238)	(1,192)
Accrued warranty reserve, ending balance	$ 4,014	$ 2,390	$ 450

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - Clementine $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)
Business Acquisition [Line Items]
Cash acquired	$ 2.9
Developed Technologies
Business Acquisition [Line Items]
Acquired intangible assets, weighted average amortization period	3 years 7 months 6 days

Acquisitions - Summary of Preli

Acquisitions - Summary of Preliminary Purchase Price Allocation for Acquisition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill	$ 873	$ 0
Clementine
Business Acquisition [Line Items]
Goodwill	873
Intangible assets	1,990
Total fair value of consideration	$ 2,863

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)ft²	Dec. 31, 2021USD ($)Month	Dec. 31, 2020USD ($)	Apr. 29, 2022USD ($)	Feb. 28, 2021USD ($)
Commitments And Contingencies [Line Items]
Operating lease number of renewal options | Month		2
Operating lease liabilities	$ 6,800	$ 7,390			$ 400
Operating lease right-of-use assets	$ 6,900	$ 7,165	$ 1,079
ROU asset and operating lease liability, weighted-average incremental borrowing rate		7.70%
Operating lease, weighted-average remaining lease term		7 years 1 month 6 days
Operating lease costs		$ 1,500	1,300
Cash paid for operating lease liabilities		1,400	1,200
Settlement Liability		$ 34,372	$ 0	$ 34,400
U.S. Government
Commitments And Contingencies [Line Items]
Settlement Liability				$ 34,400
San jose, California
Commitments And Contingencies [Line Items]
Number of square feet of office space leased | ft²	30,000
Operating lease, description		The lease commenced in September 2021 and has a 93-month term with two 60-month renewal options.

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Undiscounted Future Minimum Lease Payments Due under Non-cancelable Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021	Feb. 28, 2021
Commitments and Contingencies Disclosure [Abstract]
2022	$ 1,327
2023	1,114
2024	1,081
2025	1,331
2026	1,372
Thereafter	3,607
Total minimum future lease payments	9,832
Present value adjustment for minimum lease commitments	(2,442)
Total lease liability	$ 7,390	$ 6,800	$ 400

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Changes in Carrying Amount of Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Balance December 31, 2020	$ 0
Addition due to business acquisition	873
Balance December 31, 2021	$ 873

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of goodwill	$ 0
Amortization expense	0.3
Impairments of intangible assets	$ 0

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Summary of Intangible Assets, Net (Details) $ in Thousands	Dec. 31, 2021USD ($)
Finite Lived Intangible Assets [Line Items]
Gross carrying value	$ 1,990
Accumulated amortization	309
Net carrying value	1,681
Developed Technologies
Finite Lived Intangible Assets [Line Items]
Gross carrying value	1,700
Accumulated amortization	212
Net carrying value	1,488
Other
Finite Lived Intangible Assets [Line Items]
Gross carrying value	290
Accumulated amortization	97
Net carrying value	$ 193

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Summary of Estimated Future Amortization Expense of Finite-lived Intangible Assets, Net (Details) $ in Thousands	Dec. 31, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2022	$ 618
2023	425
2024	425
2025	213
Net carrying value	$ 1,681

Debt Obligations - Additional I

Debt Obligations - Additional Information (Details) - USD ($) $ in Thousands

May 03, 2020

Dec. 31, 2018

Sep. 30, 2020

Aug. 31, 2020

Jul. 31, 2020

Mar. 31, 2020

Jun. 30, 2019

Dec. 31, 2021

Dec. 31, 2020

Dec. 31, 2019

Sep. 30, 2021

Apr. 30, 2020

Jun. 30, 2018

Debt Instrument [Line Items]

Proceeds from debt financing

$ 0

$ 15,000

$ 5,000

Principal value

15,000

15,000

Debt, final payment as percentage of original aggregate principal amount

6.00%

Interest expense

1,068

1,920

711

Loss on extinguishment of debt

0

1,627

0

Promissory Note | CARES Act | PPP Loan

Debt Instrument [Line Items]

Repayments on outstanding debt

$ 4,600

$ 4,600

Interest expense

100

2020 Notes

Debt Instrument [Line Items]

Aggregate principal amount

$ 8,900

$ 1,200

Interest expense

900

Interest rate

6.00%

Debt instrument convert, threshold percentage of equity financing price per share

80.00%

Debt discount

$ 2,900

2020 Notes | Other Income (Expense)

Debt Instrument [Line Items]

Loss on extinguishment of debt

$ 1,600

Minimum | 2020 Notes

Debt Instrument [Line Items]

Potential proceeds from sale of equity

$ 15,000

Series E Convertible Preferred Stock

Debt Instrument [Line Items]

Percentage of share price paid by investor in preferred stock financing

80.00%

Series E Convertible Preferred Stock | 2020 Notes

Debt Instrument [Line Items]

Debt conversion, outstanding principal

$ 10,100

Debt conversion, accrued interest convertible to preferred stock, value

$ 200

2018 Loan Agreement

Debt Instrument [Line Items]

Aggregate principal amount

$ 12,500

Proceeds from debt financing

$ 7,000

2018 Loan Agreement | Series C Convertible Preferred Stock | Silicon Valley Bank

Debt Instrument [Line Items]

Warrants issued to purchase shares of convertible preferred stock

30,173

Amendments 2018 Loan Agreement

Debt Instrument [Line Items]

Aggregate principal amount

$ 20,000

Proceeds from debt financing

$ 15,000

$ 5,000

Principal value

$ 12,000

Repayments on outstanding debt

10,200

Final payment fee

9,500

Payments on existing term loan

$ 700

Debt, final payment as percentage of original aggregate principal amount

6.25%

Interest expense

$ 1,100

$ 1,000

$ 700

Effective interest rate

7.12%

Amendments 2018 Loan Agreement | Series C Convertible Preferred Stock | Silicon Valley Bank

Debt Instrument [Line Items]

Warrants issued to purchase shares of convertible preferred stock

14,999

Amendments 2018 Loan Agreement | Series E Convertible Preferred Stock | Silicon Valley Bank

Debt Instrument [Line Items]

Warrants issued to purchase shares of convertible preferred stock

53,487

Amendments 2018 Loan Agreement | Wall Street Journal Prime Rate

Debt Instrument [Line Items]

Term loans, interest rate

1.00%

(4.25%)

Debt Obligations - Schedule of

Debt Obligations - Schedule of Balance of Term Loan (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Principal value of long-term debt	$ 15,000	$ 15,000
Net of debt discount and accretion of final payment	257	(163)
Long-term debt, current and noncurrent	15,257	14,837
Less: Long-term debt, current portion	(3,333)	0
Long-term debt, noncurrent portion	$ 11,924	$ 14,837

Debt Obligations - Schedule o_2

Debt Obligations - Schedule of Future Minimum Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2022	$ 3,950
2023	7,038
2024	6,028
Total future payments	17,016
Less amounts representing interest	(1,078)
Less final payment	(938)
Total principal amount of term loan payments	$ 15,000	$ 15,000

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Aug. 31, 2020	Jul. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 20, 2020
Temporary Equity [Line Items]
Proceeds from convertible preferred stock issuance, net of issuance costs			$ 0	$ 67,867	$ 865
Common Stock
Temporary Equity [Line Items]
Convertible preferred stock converted into common stock						28,196,388
Series E Convertible Preferred Stock
Temporary Equity [Line Items]
Issuance of stock	10,513,921
Shares issued price per share	$ 6.7836
Proceeds from convertible preferred stock issuance, net of issuance costs	$ 67,300
Series E Convertible Preferred Stock | 2020 Notes
Temporary Equity [Line Items]
Conversion of convertible securities in to stock		1,889,548
Debt conversion, convertible to preferred stock, value		$ 10,300
Series C and Series C-1 Convertible Preferred Stock
Temporary Equity [Line Items]
Gain on extinguishment of Series C and Series C-1 convertible preferred stock			$ 9,800
Net carrying value				59,700
Fair value				$ 49,900

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Total Stock-based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 27,731	$ 5,089	$ 1,339
Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	738	60	16
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	6,939	822	232
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	11,213	1,629	188
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 8,841	$ 2,578	$ 903

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Details) - USD ($)	Mar. 31, 2022	Nov. 09, 2021	Oct. 31, 2020	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation costs capitalized					$ 878,000	$ 203,000	$ 0
Shares of common stock issuable upon exercise of outstanding awards					2,377,275
Weighted-average grant-date fair value of options granted					$ 24.72	$ 3.22	$ 2.85
Unrecognized stock-based compensation related to outstanding unvested stock options					$ 13,200,000
Unrecognized stock-based compensation related to outstanding unvested stock options, period of recognition					2 years 4 months 24 days
Number of shares, RSUs granted					509,860
Number of shares, RSUs vested					43,859
Total stock-based compensation					$ 27,731,000	$ 5,089,000	$ 1,339,000
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation related to outstanding unvested stock options					$ 13,900,000
Unrecognized stock-based compensation related to outstanding unvested stock options, period of recognition					3 years 4 months 24 days
Number of shares, RSUs vested					17,310
Restricted Stock Units (RSUs) | Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value	$ 100,000
Performance-based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, RSUs granted				80,000
Share-based compensation, options grants in period, grant date fair value				$ 3,000,000
Stock Option Repricing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation					$ 32,400,000	$ 5,000,000
2010 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock issuable upon exercise of outstanding awards					5,106,223
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance					6,991,055
Number of shares available for grant					6,244,669
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance					934,496
Number of shares available for grant					1,109,239
Employees eligible compensation maximum percentage					15.00%
Purchase shares of common stock at price per share equal to lesser			85.00%
Total stock-based compensation		$ 9,000			$ 17,400,000
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Refund Amount		$ 2,200,000

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Number of shares, Balance	6,468,844
Number of shares, Grants	323,105
Number of shares, Exercises	(859,200)
Number of shares, Cancelled/forfeited	(525,934)
Number of shares, Balance	5,406,815	6,468,844
Number of shares, Vested and exercisable	2,377,275
Weighted average exercise price, Balance		$ 2.78
Weighted average exercise price, Grants	$ 46.97
Weighted average exercise price, Exercises	2.01
Weighted average exercise price, Cancelled/forfeited	9.68
Weighted average exercise price, Balance	4.87
Weighted average exercise price, Vested and exercisable	$ 3.21
Weighted average remaining contractual term, Balance	7 years 10 months 17 days	8 years 9 months 7 days
Weighted average remaining contractual term, Vested and exercisable	7 years 2 months 4 days
Aggregate intrinsic value, Balance	$ 12,860	$ 271,944
Aggregate intrinsic value, Vested and exercisable	$ 6,585

Stock-based Compensation - Assu

Stock-based Compensation - Assumptions used in Estimating Grant-Date Fair Value of Stock-based Awards Using Black-Scholes Option Pricing Model (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Valuation assumptions:
Expected volatility, Minimum	53.00%	60.00%	58.00%
Expected volatility, Maximum	57.00%	71.00%	60.00%
Risk-free interest rate, Minimum	0.62%	0.23%
Risk-free interest rate, Maximum	1.11%	1.20%
Minimum
Valuation assumptions:
Expected term	5 years 9 months 18 days	5 years 1 month 6 days	5 years
Risk-free interest rate, Minimum			1.46%
Maximum
Valuation assumptions:
Expected term	6 years 8 months 12 days	7 years	10 years
Risk-free interest rate, Maximum			2.51%

Stock-based Compensation - Su_3

Stock-based Compensation - Summary of RSU Activity (Details)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Balance | shares	8,270
Number of shares, RSUs granted | shares	509,860
Number of shares, RSUs vested | shares	(43,859)
Number of shares, RSUs forfeited | shares	(125,820)
Number of shares, Balance | shares	348,451
Number of shares, Balance | $ / shares	$ 50.70
Number of shares, RSUs granted | $ / shares	43.40
Number of shares, RSUs vested | $ / shares	52.34
Number of shares, RSUs forfeited | $ / shares	41.36
Number of shares, Balance | $ / shares	$ 43.19

Stock-based Compensation - As_2

Stock-based Compensation - Assumptions Used in Estimated Fair Value of 2020 Employee Stock Purchase Plan Using Black-Scholes Option Pricing Model (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Valuation assumptions:
Expected volatility, Minimum	53.00%	60.00%	58.00%
Expected volatility, Maximum	57.00%	71.00%	60.00%
Risk-free interest rate, Minimum	0.62%	0.23%
Risk-free interest rate, Maximum	1.11%	1.20%
Minimum
Valuation assumptions:
Expected term	5 years 9 months 18 days	5 years 1 month 6 days	5 years
Risk-free interest rate, Minimum			1.46%
Maximum
Valuation assumptions:
Expected term	6 years 8 months 12 days	7 years	10 years
Risk-free interest rate, Maximum			2.51%
2020 Employee Stock Purchase Plan
Valuation assumptions:
Expected volatility, Minimum	44.00%
Expected volatility, Maximum	57.00%
Risk-free interest rate, Minimum	0.04%
Risk-free interest rate, Maximum	0.16%
2020 Employee Stock Purchase Plan | Minimum
Valuation assumptions:
Expected term	15 days
2020 Employee Stock Purchase Plan | Maximum
Valuation assumptions:
Expected term	2 months

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Income tax provision	$ 0	$ 0	$ 0
Increase in valuation allowance	37,800	8,700	3,100
Unrecognized tax benefits interest and penalties related to uncertain tax position	0	$ 0	$ 0
Accrual for payment of interest related to unrecognized tax benefits	0
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 252,600
Operating loss carryforwards expiration year	2030
Net operating loss carryforwards, indefinitely	$ 220,000
Net operating loss carryforwards, within expiration year	32,600
Federal | Research and Development Credits Carryovers
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount	$ 3,600
Tax credit carryforward expiration year	2031
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 112,600
Operating loss carryforwards expiration year	2030
State | Research and Development Credits Carryovers
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount	$ 3,800

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Statutory Federal Income Tax to Effective Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax provision at statutory rate	$ (33,128)	$ (8,370)	$ (9,342)
State income taxes, net of federal benefit	(3,104)	(826)	(2,350)
Change in valuation allowance	37,792	8,720	3,064
Stock-based compensation	(716)	(621)	190
Section 382 limitation on net operating loss and credit carryforwards			9,956
Research and development tax credits	(1,210)	(1,442)	(1,306)
Change in fair value of warrants	21	326	79
Derivative liability and extinguishment of debt		545
Return-to-provision adjustments	308	1,261	(413)
Other	37	407	122
Total current income tax provision	$ 0	$ 0	$ 0

Income Taxes - Schedule of Tax

Income Taxes - Schedule of Tax Effects of Temporary Differences and Carryforwards of Significant Portions of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 62,322	$ 35,943	$ 29,684
Research and development credits	5,120	3,910	2,468
Accruals and reserves	13,597	2,986	1,667
Lease liability	1,690
Stock-based compensation	565	589	345
Total deferred tax assets	83,294	43,428	34,164
Valuation allowance	(80,226)	(42,435)	(33,714)
Deferred tax assets after valuation allowance	3,068	993	450
Deferred tax liabilities:
Depreciation and amortization	(1,429)	(993)	(450)
Right-of-use asset	(1,639)
Total deferred tax liabilities	(3,068)	(993)	(450)
Net deferred tax assets	$ 0	$ 0	$ 0

Income Taxes - Schedule of Re_2

Income Taxes - Schedule of Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Beginning balance	$ 1,676	$ 1,058	$ 576
Increases related to current year tax positions	518	618	482
Ending balance	$ 2,194	$ 1,676	$ 1,058

Ne Loss Per Share Attributable

Ne Loss Per Share Attributable To Common Stockholders - Summary of Outstanding Potentially Dilutive Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	5,835,266	6,494,979	17,258,207
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share			13,710,242
Common Stock Options Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	5,406,815	6,468,844	3,474,052
Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	428,451	8,270
Shares Issuable Pursuant to ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share		17,865
Convertible Preferred Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share			73,913

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable To Common Stockholders - Computation of Basic And Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ (157,754)	$ (39,855)	$ (44,486)
Gain on extinguishment of Series C and Series C-1 convertible preferred stock		9,840
Net loss attributable to common stockholders, basic and diluted	$ (157,754)	$ (30,015)	$ (44,486)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	38,899,457	7,890,375	256,452
Net loss per share attributable to common stockholders, basic and diluted	$ (4.06)	$ (3.80)	$ (173.47)

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Thousands	Apr. 29, 2022	Dec. 31, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Settlement Liability	$ 34,400	$ 34,372	$ 0
Civil Settlement Agreement
Subsequent Event [Line Items]
Settlement Liability		$ 34,400