Inogen Inc 10-K

ITEM 8. FINANCIAL STATEMENTS AN D SUPPLEMENTARY DATA The financial statements and supplementary data required by this item are included in Part IV, Item 15 of this Report. ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE None. 84 ITEM 9A. CONTRO LS AND PROCEDURES Evaluation of disclosure controls and procedures The Company maintains a system of disclosure controls and procedures as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which are designed to provide reasonable assurance that information required to be disclosed in the reports that the Company files or submits under the Exchange Act, is recorded, processed, summarized and reported accurately and completely within the time periods specified in the SEC’s rules and forms. These disclosure controls and procedures include, among other processes, controls and procedures designed to ensure that information required to be disclosed in the reports that the Company files or submits under the Exchange Act is accumulated and communicated to management, including the Chief Executive Officer and Chief Financial Officer, as appropriate, to allow timely decisions regarding required disclosure. Due to inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Further, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions over time, or that the degree of compliance with the policies and procedures may deteriorate. Accordingly, even effective disclosure controls and procedures can only provide reasonable assurance of achieving their control objectives. Our management, with the participation of our Chief Executive Officer and our Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2023. Based upon the evaluation described above, our Chief Executive Officer and Chief Financial Officer concluded that, as of December 31, 2023, our disclosure controls and procedures were effective at the reasonable assurance level. Changes in internal controls over financial reporting There has been no change in our internal control over financial reporting identified in connection with the evaluation required by paragraph (d) of Rule 13a-15 or 15d-15 that occurred during our most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting. Limitations on effectiveness of controls In designing and evaluating the disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. In addition, the design of disclosure controls and procedures must reflect the fact that there are resource constraints, and that management is required to apply its judgment in evaluating the benefits of possible controls and procedures relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, have been detected. Because of the inherent limitations in any control system, misstatements due to error or fraud may occur and not be detected. Management’s report on internal control over financial reporting Our management is responsible for establishing and maintaining adequate internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act). Our management, including our Chief Executive Officer and Chief Financial Officer, conducted an assessment of the effectiveness of our internal control over financial reporting based on the criteria set forth in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework) (COSO). Based on our evaluation under the COSO framework, our management concluded that our internal control over financial reporting was effective as of December 31, 2023 to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements in accordance with U.S. GAAP. The effectiveness of our internal control over financial reporting as of December 31, 2023 has been audited by our independent registered public accounting firm, Deloitte & Touche LLP, as stated in their report, which appears herein. For purposes of conducting its 2023 evaluation of the effectiveness of the Company's internal control over financial reporting, management has excluded the acquisition of Physio-Assist, completed on September 14, 2023, which constitutes 1% of total assets (excluding goodwill and intangible assets, which were integrated into the Company’s control environment) and less than 1% of revenues. Refer to Note 3 – Acquisitions in the notes to the consolidated financial statements included in Part IV, Item 16, "Form 10-K Summary" of this Annual Report on Form 10-K for further discussion. 85 REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM To the stockholders and the Board of Directors of Inogen, Inc. Opinion on Internal Control over Financial Reporting We have audited the internal control over financial reporting of Inogen, Inc. and subsidiaries (the “Company”) as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework (2013) issued by COSO. We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated financial statements as of and for the year ended December 31, 2023, of the Company and our report dated March 1, 2024, expressed an unqualified opinion on those financial statements. As described in Management's Report on Internal Control over Financial Reporting, management excluded from its assessment the internal control over financial reporting at Physio-Assist SAS ("Physio-Assist"), which was acquired on September 14, 2023, and whose financial statements constitute 1% of total assets (excluding goodwill and intangible assets, which were integrated into the Company’s control environment) and less than 1% of revenues of the consolidated financial statement amounts as of and for the year ended December 31, 2023. Accordingly, our audit did not include the internal control over financial reporting at Physio-Assist. Basis for Opinion The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Report on Internal Control over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion. Definition and Limitations of Internal Control over Financial Reporting A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements. Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. /s/ DELOITTE & TOUCHE LLP Los Angeles, California March 1, 2024 86 ITEM 9B. OTHER IN FORMATION Annual Meeting Our annual meeting of stockholders will be held at 10:00 a.m. Pacific Time on Wednesday, June 5, 2024, as a virtual meeting. Holders of record at the close of business on Monday, April 8, 2024, will be entitled to vote at the meeting. Insider Trading Arrangements None. ITEM 9C. DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS Not applicable. 87 PART III ITEM 10. DIRECTORS, EXECUTIVE OF FICERS AND CORPORATE GOVERNANCE The information called for by this item will be set forth in our Proxy Statement for the Annual Meeting of Stockholders to be filed with the SEC within 120 days of the fiscal year ended December 31, 2023 (the “Proxy Statement”) and is incorporated herein by reference. Our board of directors has adopted a Code of Ethics and Conduct that applies to all of our employees, officers and directors, including our Chief Executive Officer, Chief Financial Officer and other executive and senior financial officers. The full text of our Code of Ethics and Conduct is posted on the investor relations page on our website which is located at http://investor.inogen.com . We will post any amendments to our code of business conduct and ethics, or waivers of its requirements, on our website. ITEM 11. EXECUTI VE COMPENSATION The information required by this item will be disclosed in the Proxy Statement and is incorporated herein by reference. ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWN ERS AND MANAGEMENT AND RELATED STOCKHOLDERS MATTERS The information required by this item will be disclosed in the Proxy Statement and is incorporated herein by reference. ITEM 13. CERTAIN RELATIONSHIPS AND RELATE D TRANSACTIONS, AND DIRECTOR INDEPENDENCE The information required by this item will be disclosed in the Proxy Statement and is incorporated herein by reference. I TEM 14. PRINCIPAL ACCOUNTANT FEES AND SERVICES The information required by this item will be disclosed in the Proxy Statement and is incorporated herein by reference. 88 PART IV ITEM 15. EXHIBITS, FINANCIAL S TATEMENT SCHEDULES (a) The following documents are filed as part of this Annual Report on Form 10-K: 1. Financial Statements The consolidated financial statements listed in the accompanying index (page F-1) to the consolidated financial statements are filed as part of this Annual Report on Form 10-K. 2. Financial Statement Schedules See Schedule II – Valuation and Qualifying Accounts and Reserves included herein. All other schedules have been omitted because the information either has been shown in the financial statements or notes thereto or is not applicable or required under this section. (b) Exhibits Exhibits are filed as part of this Annual Report on Form 10-K and are hereby incorporated by reference. Refer to Exhibit Index included herein. ITEM 16. FO RM 10-K SUMMARY None. 89 Inogen, Inc. Index to Financial Statements and Financial Statement Schedule Report of Independent Registered Public Accounting Firm F- 2 Financial Statements Consolidated Balance Sheets as of December 31, 2023 and 2022 F- 4 Consolidated Statements of Comprehensive Loss for the Years Ended December 31, 2023, 2022 and 2021 F- 5 Consolidated Statements of Stockholders’ Equity for the Years Ended December 31, 2023, 2022 and 2021 F- 6 Consolidated Statements of Cash Flows for the Years Ended December 31, 2023, 2022 and 2021 F- 7 Notes to the Consolidated Financial Statements F- 9 Financial Statement Schedule Valuation and Qualifying Accounts for the Years Ended December 31, 2023, 2022 and 2021 F- 35 F- 1 REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM To the stockholders and the Board of Directors of Inogen, Inc. Opinion on the Financial Statements We have audited the accompanying consolidated balance sheets of Inogen, Inc. and subsidiaries (the "Company") as of December 31, 2023 and 2022, the related consolidated statements of comprehensive loss, stockholders' equity, and cash flows for each of the three years in the period ended December 31, 2023, and the related notes and the schedule listed in the Index at Item 15 (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America. We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated March 1, 2024, expressed an unqualified opinion on the Company's internal control over financial reporting. Basis for Opinion These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion. Critical Audit Matter The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates. Sales Revenue (Amounts Deferred for Lifetime Warranty) – Refer to Note 2 to the financial statements Critical Audit Matter Description The Company offers a lifetime warranty for direct-to-consumer sales of its oxygen concentrators. For a fixed price, the Company agrees to provide a fully functional oxygen concentrator for the remaining life of the patient. Lifetime warranties are only offered to patients upon the initial sale of oxygen concentrators directly from the Company and are non-transferable. Lifetime warranties are considered to be a distinct performance obligation that are accounted for separately from its sale of oxygen concentrators with a standard warranty of three years. The revenue is allocated to the distinct lifetime warranty performance obligation based on a relative stand-alone selling price (SSP) method. The Company has vendor-specific objective evidence of the selling price for its equipment. To determine the selling price of the lifetime warranty, the Company uses its best estimate of the SSP for the distinct performance obligation as the lifetime warranty is neither separately priced nor is the selling price available through third-party evidence. To estimate the selling price associated with the lifetime warranties, management considers the profit margins of service revenue, the average estimated cost of lifetime warranties and the price of extended warranties. Revenue from the distinct lifetime warranty is deferred after the delivery of the equipment and recognized based on an estimated mortality rate over five years, which is the estimated performance period of the contract based on the average patient life expectancy. Total deferred revenue related to the lifetime warranty performance obligation totaled $13.3 million at December 31, 2023. F- 2 Determining the estimated SSP requires significant judgment by management, which is informed by considering Company specific and external data. The service period used to amortize the deferred revenue also requires significant management judgment as the Company has limited historical experience and the determination of patient life expectancy is subjective in nature. Given the lack of stand-alone transactions together with the limited amount of historical data available for such offering, performing audit procedures to evaluate the estimated SSP and the service period for lifetime warranty required high degree of auditor judgment and an increased extent of effort. How the Critical Audit Matter Was Addressed in the Audit Our audit procedures related to management’s judgments regarding the stand-alone selling price and deferred revenue service period included the following, among others: • We tested the effectiveness of controls over deferred revenue for the lifetime warranty, including controls over the underlying data utilized and the selection of the stand-alone selling price and the deferred revenue service period. • We evaluated the methodology used by management to develop the stand-alone selling price and independently estimated the stand-alone selling price selected by management. In performing these procedures, we compared the stand-alone selling price selected by management to the independent estimate, which utilized external evidence of similar term extended warranties for oxygen concentrators and the Company’s profit margins. • We evaluated the reasonableness of the deferred revenue service period by comparing to patient average life expectancy in medical and other industry publications. We further evaluated the realization of deferred revenue by evaluating the appropriateness of the underlying mortality data. /s/ DELOITTE & TOUCHE LLP Los Angeles, California March 1, 2024 We have served as the Company’s auditor since 2015. F- 3 Inogen, Inc. Conso lidated Balance Sheets (amounts in thousands, except share and per share amounts) December 31, 2023 2022 Assets Current assets Cash and cash equivalents $ 125,492 $ 187,014 Marketable securities 2,979 — Accounts receivable, net 42,241 62,725 Inventories, net 21,840 34,093 Income tax receivable 669 1,626 Prepaid expenses and other current assets 13,846 19,187 Total current assets $ 207,067 $ 304,645 Property and equipment, net 50,316 43,269 Goodwill 10,057 32,852 Intangible assets, net 34,591 177 Operating lease right-of-use asset 20,338 21,653 Other assets 3,825 2,445 Total assets $ 326,194 $ 405,041 Liabilities and stockholders' equity Current liabilities Accounts payable and accrued expenses $ 30,142 $ 33,974 Accrued payroll 11,066 11,190 Warranty reserve - current 9,628 7,790 Operating lease liability - current 3,653 3,515 Earnout liability 10,000 — Deferred revenue - current 7,980 8,880 Income tax payable 27 — Total current liabilities $ 72,496 $ 65,349 Long-term liabilities Warranty reserve - noncurrent 13,850 12,123 Operating lease liability - noncurrent 18,270 19,764 Deferred revenue - noncurrent 8,227 10,399 Deferred tax liability 8,539 — Total liabilities $ 121,382 $ 107,635 Commitments and contingencies (Note 9) Stockholders' equity Common stock, $ 0.001 par value per share; 200,000,000 shares authorized; 23,324,750 and 22,941,643 shares issued and outstanding as of December 31, 2023 and 2022, respectively $ 23 $ 23 Additional paid-in capital 320,513 312,126 Accumulated deficit ( 116,949 ) ( 14,500 ) Accumulated other comprehensive income (loss) 1,225 ( 243 ) Total stockholders' equity $ 204,812 $ 297,406 Total liabilities and stockholders' equity $ 326,194 $ 405,041 See accompanying notes to the consolidated financial statements. F- 4 Inogen, Inc. Consolidated Statements of Comprehensive Loss (amounts in thousands, except share and per share amounts) Years Ended December 31, 2023 2022 2021 Revenue Sales revenue $ 251,607 $ 320,549 $ 311,730 Rental revenue 64,053 56,692 46,273 Total revenue 315,660 377,241 358,003 Cost of revenue Cost of sales revenue 158,636 197,805 161,824 Cost of rental revenue, including depreciation of $ 12,893 , $ 11,103 and $ 8,860 , respectively 30,325 25,903 19,696 Total cost of revenue 188,961 223,708 181,520 Gross profit Gross profit-sales revenue 92,971 122,744 149,906 Gross profit-rental revenue 33,728 30,789 26,577 Total gross profit 126,699 153,533 176,483 Operating expense Research and development 20,840 21,943 16,576 Sales and marketing 107,091 120,767 112,815 General and administrative 75,260 43,905 37,852 Loss on disposal of intangible asset — 52,161 — Impairment charges 32,894 — — Total operating expense 236,085 238,776 167,243 Income (loss) from operations ( 109,386 ) ( 85,243 ) 9,240 Other income (expense) Interest income, net 6,574 2,837 129 Other income (expense) 468 ( 862 ) ( 710 ) Total other income (expense), net 7,042 1,975 ( 581 ) Income (loss) before provision for income taxes ( 102,344 ) ( 83,268 ) 8,659 Provision for income taxes 105 504 14,992 Net loss ( 102,449 ) ( 83,772 ) ( 6,333 ) Other comprehensive income (loss), net of tax Change in foreign currency translation adjustment 1,358 ( 597 ) ( 800 ) Change in net unrealized gains (losses) on foreign currency hedging — ( 3,130 ) 1,746 Less: reclassification adjustment for net (gains) losses included in net loss — 1,990 47 Total net change in unrealized gains (losses) on foreign currency hedging — ( 1,140 ) 1,793 Change in net unrealized gains (losses) on marketable securities 110 25 1 Total other comprehensive income (loss), net of tax 1,468 ( 1,712 ) 994 Comprehensive loss $ ( 100,981 ) $ ( 85,484 ) $ ( 5,339 ) Basic net loss per share attributable to common stockholders (Note 2) $ ( 4.42 ) $ ( 3.67 ) $ ( 0.28 ) Diluted net loss per share attributable to common stockholders (Note 2) $ ( 4.42 ) $ ( 3.67 ) $ ( 0.28 ) Weighted-average number of shares used in calculating net loss per share attributable to common stockholders: Basic common shares 23,176,098 22,852,571 22,490,027 Diluted common shares 23,176,098 22,852,571 22,490,027 See accompanying notes to the consolidated financial statements. F- 5 Inogen, Inc. Consolidated Sta tements of Stockholders’ Equity (amounts in thousands, except share amounts) Retained Accumulated Additional earnings other Total Common stock paid-in (accumulated comprehensive stockholders' Shares Amount capital (deficit) income (loss) equity Balance, December 31, 2020 22,131,447 $ 22 $ 273,521 $ 75,605 $ 475 $ 349,623 Stock-based compensation — — 10,943 — — 10,943 Employee stock purchases 60,299 — 1,948 — — 1,948 Restricted stock awards issued, net of forfeitures ( 43,658 ) — — — — — Vesting of restricted stock units 101,811 — ( 412 ) — — ( 412 ) Shares withheld related to net restricted stock settlement ( 4,351 ) — ( 235 ) — — ( 235 ) Stock options exercised 486,038 1 13,698 — — 13,699 Net loss — — — ( 6,333 ) — ( 6,333 ) Other comprehensive income — — — — 994 994 Balance, December 31, 2021 22,731,586 $ 23 $ 299,463 $ 69,272 $ 1,469 $ 370,227 Stock-based compensation — — 12,283 — — 12,283 Employee stock purchases 62,328 — 1,691 — — 1,691 Restricted stock awards issued, net of forfeitures ( 5,134 ) — — — — — Vesting of restricted stock units 141,728 — ( 1,252 ) — — ( 1,252 ) Shares withheld related to net restricted stock settlement ( 3,019 ) — ( 103 ) — — ( 103 ) Stock options exercised 14,154 — 44 — — 44 Net loss — — — ( 83,772 ) — ( 83,772 ) Other comprehensive loss — — — — ( 1,712 ) ( 1,712 ) Balance, December 31, 2022 22,941,643 $ 23 $ 312,126 $ ( 14,500 ) $ ( 243 ) $ 297,406 Stock-based compensation — — 7,427 — — 7,427 Employee stock purchases 136,032 — 1,094 — — 1,094 Vesting of restricted stock units 192,735 — ( 517 ) — — ( 517 ) Shares withheld related to net restricted stock settlement ( 92 ) — ( 1 ) — — ( 1 ) Stock options exercised 54,432 — 384 — — 384 Net loss — — — ( 102,449 ) — ( 102,449 ) Other comprehensive income — — — — 1,468 1,468 Balance, December 31, 2023 23,324,750 $ 23 $ 320,513 $ ( 116,949 ) $ 1,225 $ 204,812 See accompanying notes to the consolidated financial statements. F- 6 Inogen, Inc. Consoli dated Statements of Cash Flows (amounts in thousands) Years Ended December 31, 2023 2022 2021 Cash flows from operating activities Net loss $ ( 102,449 ) $ ( 83,772 ) $ ( 6,333 ) Adjustments to reconcile net loss to net cash provided by (used in) operating activities: Depreciation and amortization 18,152 23,514 21,628 Loss on rental assets and other assets 4,508 3,095 1,521 Gain on sale of former rental assets ( 84 ) ( 154 ) ( 65 ) Provision for sales revenue returns and doubtful accounts 10,730 13,024 11,094 Provision for inventory losses 2,691 2,423 2,062 Loss on purchase commitments 2,057 — — Stock-based compensation expense 7,427 12,283 10,943 Deferred income taxes ( 251 ) — 14,444 Change in fair value of earnout liability 6,822 ( 15,386 ) ( 11,596 ) Loss on disposal of intangible asset — 52,161 — Impairment charges 32,894 — — Changes in operating assets and liabilities: Accounts receivable 10,141 ( 51,337 ) ( 6,127 ) Inventories 7,878 ( 5,601 ) ( 10,775 ) Income tax receivable 988 ( 281 ) 705 Prepaid expenses and other current assets 5,583 6,803 ( 8,104 ) Operating lease right-of-use asset 3,413 3,259 ( 16,087 ) Other noncurrent assets ( 1,110 ) 224 96 Accounts payable and accrued expenses ( 9,177 ) 6,759 ( 6,476 ) Accrued payroll ( 508 ) ( 6,106 ) 10,231 Warranty reserve 3,565 6,187 ( 668 ) Deferred revenue ( 3,075 ) ( 1,150 ) 1,613 Income tax payable 27 ( 82 ) ( 1,141 ) Operating lease liability ( 3,456 ) ( 3,395 ) 16,668 Net cash provided by (used in) operating activities ( 3,234 ) ( 37,532 ) 23,633 Cash flows from investing activities Purchases of available-for-sale securities ( 26,869 ) — ( 9,987 ) Maturities of available-for-sale securities 24,000 10,014 19,256 Investment in intangible assets ( 494 ) — ( 132 ) Investment in property and equipment ( 5,218 ) ( 3,337 ) ( 5,482 ) Production and purchase of rental equipment ( 21,299 ) ( 17,885 ) ( 18,453 ) Proceeds from sale of former assets 198 331 153 Acquisition of business, net of cash acquired ( 29,633 ) — — Net cash used in investing activities ( 59,315 ) ( 10,877 ) ( 14,645 ) See accompanying notes to the consolidated financial statements. F- 7 Inogen, Inc. Consolidated Statements of Cash Flows (continued) (amounts in thousands) Years Ended December 31, 2023 2022 2021 Cash flows from financing activities Proceeds from stock options exercised 384 44 13,699 Proceeds from employee stock purchases 1,094 1,691 1,948 Payment of employment taxes related to release of restricted stock ( 518 ) ( 1,355 ) ( 647 ) Net cash provided by financing activities 960 380 15,000 Effect of exchange rates on cash 67 ( 481 ) ( 426 ) Net increase (decrease) in cash and cash equivalents ( 61,522 ) ( 48,510 ) 23,562 Cash and cash equivalents, beginning of period 187,014 235,524 211,962 Cash and cash equivalents, end of period $ 125,492 $ 187,014 $ 235,524 Supplemental disclosures of cash flow information Cash paid (received) during the period for income taxes, net of refunds received $ ( 703 ) $ 499 $ 1,544 Supplemental disclosure of non-cash transactions Accrued value of earnout related to acquisition 3,178 — — Property and equipment in accounts payable and accrued liabilities 204 428 353 See accompanying notes to the consolidated financial statements. F- 8 Inogen, Inc. Notes to the Consolidat ed F inancial Statements (amounts in thousands, except share and per share amounts) 1. Nature of business Inogen, Inc. (Company or Inogen) was incorporated in Delaware on November 27, 2001. The Company is a medical technology business that primarily develops, manufactures, and markets innovative portable oxygen concentrators (POCs) used to deliver supplemental long-term oxygen therapy to patients suffering from chronic respiratory conditions. Traditionally, these patients have relied on stationary oxygen concentrator systems for use in the home and oxygen tanks or cylinders for mobile use, which the Company refers to as the delivery model. The tanks and cylinders must be delivered regularly and have a finite amount of oxygen, which requires patients to plan activities outside of their homes around delivery schedules and a finite oxygen supply. Additionally, patients must attach long, cumbersome tubing to their stationary concentrators simply to enable mobility within their homes. The Company’s proprietary Inogen One® and Inogen Rove systems concentrate the air around the patient to offer a source of supplemental oxygen anytime, anywhere with a battery and can be plugged into an outlet when at home, in a car, or in a public place with outlets available. The Company’s Inogen One systems reduce the patient’s reliance on stationary concentrators and scheduled deliveries of tanks with a finite supply of oxygen, thereby improving patient quality of life and fostering mobility. The Company incorporated Inogen Europe Holding B.V., a Dutch limited liability company, on April 13, 2017 . On May 4, 2017, Inogen Europe Holding B.V. acquired all issued and outstanding capital stock of MedSupport Systems B.V. (MedSupport) and began operating under the name Inogen Europe B.V. The Company merged Inogen Europe Holding B.V. and Inogen Europe B.V. on December 28, 2018. Inogen Europe B.V. is the remaining legal entity. Inogen completed the acquisition of New Aera, Inc. (New Aera) on August 9, 2019. On September 14, 2023 , the Company completed the acquisition of all of the issued and outstanding capital stock of Physio-Assist SAS (Physio-Assist) and its wholly-owned subsidiary PhysioAssist GmbH. 2. Summary of significant accounting policies Basis of presentation The consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP). Basis of consolidation The consolidated financial statements include the accounts of Inogen, Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated. Accounting estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases these estimates and assumptions upon historical experience, existing and known circumstances, authoritative accounting pronouncements and other factors that management believes to be reasonable. Significant areas requiring the use of management estimates relate to revenue recognition, warranty reserves and expense, determining the stand-alone selling price (SSP) and service period of performance obligations, rental asset valuations and write-downs, accounts receivable allowances for bad debts, returns and adjustments, impairment of goodwill, impairment of long-lived assets, stock-based compensation expense, income taxes, fair value of acquired intangible assets and goodwill, and fair value of earnout liabilities. Actual results could differ from these estimates. Revenue The Company generates revenue primarily from sales and rentals of its products. The Company’s products consist primarily of its proprietary line of oxygen concentrators, and related accessories. Other revenue, which is included in sales revenue on the statements of comprehensive loss, primarily comes from service contracts, replacement parts and freight revenue for product shipments. F- 9 Sales revenue Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. Revenue from product sales is generally recognized upon shipment of the product but is deferred for certain transactions when control has not yet transferred to the customer. The Company’s product is generally sold with a right of return and the Company may provide other incentives, which are accounted for as variable consideration when estimating the amount of revenue to recognize. Returns and incentives are estimated at the time sales revenue is recognized. The provision for estimated returns is calculated based on historical data and future expectations. Sales revenue incentives within the Company’s contracts are estimated based on the most likely amounts expected on the related sales transactions and recorded as a reduction to revenue at the time of sale in accordance with the terms of the contract. Accordingly, revenue is recognized net of allowances for estimated returns and incentives. For a fixed price, the Company also offers a lifetime warranty for direct-to-consumer sales for its oxygen concentrators. Lifetime warranties are only offered to patients upon the initial sale of oxygen concentrators directly from the Company and are non-transferable. Lifetime warranties are considered to be a distinct performance obligation that are accounted for separately from its sale of oxygen concentrators with a standard warranty of three years . The revenue is allocated to the distinct lifetime warranty performance obligation based on a relative SSP method. The Company has vendor-specific objective evidence of the selling price for its equipment. To determine the selling price of the lifetime warranty, the Company uses its best estimate of the SSP for the distinct performance obligation as the lifetime warranty is neither separately priced nor is the selling price available through third-party evidence. To calculate the selling price associated with the lifetime warranties, management considers the profit margins of service revenue, the average estimated cost of lifetime warranties and the price of extended warranties. Revenue from the distinct lifetime warranty is deferred after the delivery of the equipment and recognized based on an estimated mortality rate over five years, which is the estimated performance period of the contract based on the average patient life expectancy. Revenue from the sale of the Company’s repair services is recognized when the performance obligations are satisfied and collection of the receivables is probable. Other revenue from the sale of replacement parts is generally recognized when product is shipped to customers. Freight revenue consists of fees associated with the deployment of products internationally and domestically when expedited freight options are requested or when minimum order quantities are not met. Freight revenue is generally recognized upon shipment of the product but is deferred if control has not yet transferred to the customer. Shipping and handling costs for sold products and rental assets shipped to the Company’s customers are included on the consolidated statements of comprehensive loss as part of cost of sales revenue and cost of rental revenue, respectively. The payment terms and conditions of customer contracts vary by customer type and the products and services offered. For certain products or services and customer types, the Company requires payment before the products or services are delivered to the customer. The timing of sales revenue recognition, billing and cash collection results in billed accounts receivable and deferred revenue in the consolidated balance sheets. Contract liabilities primarily consist of deferred revenue related to lifetime warranties on direct-to-consumer sales revenue when cash payments are received in advance of services performed under the contract. The contract with the customer states the final terms of the sale, including the description, quantity, and price of each product or service purchase. The decrease in deferred revenue related to lifetime warranties for the years ended December 31, 2023 and December 31, 2022 was primarily driven by $ 6,438 and $ 6,598 , respectively, of revenues recognized that were included in the deferred revenue balances, partially offset by $ 3,219 and $ 5,156 of payments received in advance of satisfying performance obligations as of December 31, 2023 and December 31, 2022 , respectively. Deferred revenue related to lifetime warranties was $ 13,315 and $ 16,534 as of December 31, 2023 and December 31, 2022, respectively, and is classified within deferred revenue – current and noncurrent deferred revenue in the consolidated balance sheets. The Company elected to apply the practical expedient in accordance with Accounting Standards Codification (ASC) 606— Revenue Recognition and did not evaluate contracts of one year or less for the existence of a significant financing component. The Company does not expect any revenue to be recognized over a multi-year period with the exception of revenue related to lifetime warranties. F- 10 The Company’s sales revenue is primarily derived from the sale of its oxygen concentrator products to individual consumers, home medical equipment providers, distributors, the Company’s private label partner and resellers worldwide. Sales revenue is classified into two areas: business-to-business sales and direct-to-consumer sales. The following table sets forth the Company’s sales revenue disaggregated by sales channel and geographic region: Years ended December 31, Revenue by region and category 2023 2022 2021 Business-to-business domestic sales $ 66,196 $ 86,049 $ 91,371 Business-to-business international sales 89,401 101,163 79,460 Direct-to-consumer domestic sales 96,010 133,337 140,899 Total sales revenue $ 251,607 $ 320,549 $ 311,730 Rental revenue The Company recognizes equipment rental revenue over the non-cancelable lease term, which is one month, less estimated adjustments, in accordance with Accounting Standards Codification (ASC) 842— Leases . The Company has separate contracts with each patient that are not subject to a master lease agreement with any third-party payor. The Company evaluates the individual lease contracts at lease inception and the start of each monthly renewal period to determine if it is reasonably certain that the monthly renewal option and the bargain renewal option associated with the potential capped free rental period would be exercised. Historically, the exercise of the monthly renewal and bargain renewal option is not reasonably certain at lease inception and at most subsequent monthly lease renewal periods. If the Company determines that the reasonably certain threshold for an individual patient is met at lease inception or at a monthly lease renewal period, such determination would impact the bargain renewal period for an individual lease. The Company would first consider the lease classification issue (sales-type lease or operating lease) and then appropriately recognize or defer rental revenue over the lease term, which may include a portion of the capped rental period. The Company has no t deferred any amounts associated with the capped rental period as of December 31, 2023 and December 31, 2022. Amounts related to the capped rental period have not been material in the periods presented. The lease term begins on the date products are shipped to patients and are recorded at amounts estimated to be received under reimbursement arrangements with third-party payors, including Medicare, private payors, and Medicaid. Due to the nature of the industry and the reimbursement environment in which the Company operates, certain estimates are required to record net revenue and accounts receivable at their net realizable values. Inherent in these estimates is the risk that they will have to be revised or updated as additional information becomes available. Specifically, the complexity of many third-party billing arrangements and the uncertainty of reimbursement amounts for certain services from certain payors may result in adjustments to amounts originally recorded. Such adjustments are typically identified and recorded at the point of cash application, claim denial or account review. The Company adjusts revenue for historical trends on revenue adjustments due to timely filings, deaths, hospice, and other types of analyzable adjustments on a monthly basis to record rental revenue at the expected collectible amounts. Accounts receivable is reduced by an allowance for doubtful accounts which provides for those accounts from which payment is not expected to be received although product was delivered and revenue was earned. The determination that an account is uncollectible, and the ultimate write-off of that account occurs once collection is considered to be highly unlikely, and it is written-off and charged to the allowance at that time. Amounts billed but not earned due to the timing of the billing cycle are deferred and recognized in revenue on a straight-line basis over the monthly billing period. For example, if the first day of the billing period does not fall on the first of the month, then a portion of the monthly billing period will fall in the subsequent month and the related revenue and cost would be deferred based on the service days in the following month. The lease agreements generally contain lease and non-lease components. Non-lease components primarily include payments for supplies. The Company elected the practical expedient to treat the lease and non-lease components as a single lease component. Rental revenue is recognized as earned, less estimated adjustments. Revenue not billed at the end of the period is reviewed for the likelihood of collections and accrued. The rental revenue stream is not guaranteed, and payment will cease if the patient no longer needs oxygen or returns the equipment. Revenue recognized is at full estimated allowable amounts; transfers to secondary insurances or patient responsibility have no net effect on revenue. Rental revenue is earned for that entire month if the patient is on service on the first day of the 30 -day period commencing on the recurring date of service for a particular claim, regardless of whether there is a change in condition or death after that date. Included in rental revenue are unbilled amounts for which the revenue recognition criteria had been met as of period-end but were not yet billed to the payor. The estimate of net unbilled rental revenue recognized is based on historical trends and estimates of future collectability. In addition, the Company estimates potential future adjustments and write-offs of these unbilled amounts and includes these estimates in the allowance for adjustments and write-offs of rental revenue which is netted against gross receivables. F- 11 Product Warranty The Company generally provides a warranty against defects in material and workmanship. The Company provides a 3-year, 5-year or lifetime warranty on Inogen One systems and a 3-year and lifetime warranty on Inogen At Home systems sold. The Company only offers a lifetime warranty for direct-to-consumer sales of its oxygen concentrators. For a fixed price, the Company agrees to provide a fully functional oxygen concentrator for the remaining life of the patient. Lifetime warranties are only offered to patients upon the initial sale of oxygen concentrators directly from the Company and are non-transferable. The Company’s products are subject to regulatory and quality standards. The Company establishes an accrued liability for the estimated warranty costs at the time of revenue recognition, with a corresponding provision to cost of goods sold. The Company evaluates the liability each reporting period. Warranty costs are primarily estimated based on product return rates, historical warranty repair costs incurred and historical failure rates. The Company may make further adjustments to the warranty reserve when deemed appropriate, giving additional consideration to length of time the product version has been sold and future expectations of performance based on new features and capabilities. Actual warranty costs could differ materially from the estimated amounts. Fair value accounting ASC 820 — Fair Value Measurements and Disclosures creates a single definition of fair value, establishes a framework for measuring fair value in U.S. GAAP and expands disclosures about fair value measurements. ASC 820 emphasizes that fair value is a market-based measurement, not an entity-specific measurement, and states that a fair value measurement is to estimate the price at which an orderly transaction to sell an asset or to transfer the liability would take place between market participants at the measurement date under current market conditions. Assets and liabilities adjusted to fair value in the balance sheet are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Level inputs, as defined by ASC 820, are as follows: Level input Input definition Level 1 Inputs are unadjusted, quoted prices for identical assets or liabilities in active markets at the measurement date. Level 2 Inputs, other than quoted prices included in Level 1, that are observable for the asset or liability through corroboration with market data at the measurement date. Level 3 Unobservable inputs that reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. The Company’s financial instruments consist of cash and cash equivalents, marketable securities, accounts receivable, accounts payable and accrued expenses. The carrying values of its financial instruments approximate fair value based on their short-term nature. Fair value of financial instruments The Company obtained the fair value of its available-for-sale investments, which are not in active markets, from a third-party professional pricing service using quoted market prices for identical or comparable instruments, rather than direct observations of quoted prices in active markets. The Company's professional pricing service gathers observable inputs for all of its fixed income securities from a variety of industry data providers (e.g., large custodial institutions) and other third-party sources. Once the observable inputs are gathered, all data points are considered, and the fair value is determined. The Company validates the quoted market prices provided by its primary pricing service by comparing their assessment of the fair values against the fair values provided by its investment managers. The Company's investment managers use similar techniques to its professional pricing service to derive pricing as described above. As all significant inputs were observable, derived from observable information in the marketplace or supported by observable levels at which transactions are executed in the marketplace, the Company has classified its marketable securities within Level 2 of the fair value hierarchy. F- 12 The following table summarizes fair value measurements by level for the assets measured at fair value on a recurring basis for cash, cash equivalents and marketable securities: As of December 31, 2023 Gross Cash Adjusted unrealized and cash Marketable cost gains Fair value equivalents securities Cash $ 12,611 $ — $ 12,611 $ 12,611 $ — Level 1: Money market accounts 72,368 — 72,368 72,368 — Level 2: Corporate bonds 2,979 — 2,979 — 2,979 U.S. Treasury securities 19,252 136 19,388 19,388 — Institutional Insured Liquidity Deposit Savings 21,125 — 21,125 21,125 — Total $ 128,335 $ 136 $ 128,471 $ 125,492 $ 2,979 As of December 31, 2022 Gross Cash Adjusted unrealized and cash cost gains Fair value equivalents Cash $ 27,970 $ — $ 27,970 $ 27,970 Level 1: Money market accounts 113,534 — 113,534 113,534 Level 2: Corporate bonds 6,474 — 6,474 6,474 U.S. Treasury securities 18,913 26 18,939 18,939 Institutional Insured Liquidity Deposit Savings 20,097 — 20,097 20,097 Total $ 186,988 $ 26 $ 187,014 $ 187,014 Fair value of derivative instruments and hedging activities The Company transacts business in foreign currencies and has international sales and expenses denominated in foreign currencies, subjecting the Company to foreign currency risk. The Company has entered into foreign currency forward contracts, generally with maturities of twelve months or less, to reduce the volatility of cash flows, primarily related to forecasted revenue denominated in certain foreign currencies. These contracts allow the Company to sell Euros in exchange for U.S. dollars at specified contract rates. Forward contracts are used to hedge forecasted sales over specific months. Changes in the fair value of these forward contracts designed as cash flow and balance sheet hedges are recorded as a component of accumulated other comprehensive income within stockholders’ equity and are recognized in the consolidated statements of comprehensive loss during the period which approximates the time the corresponding sales occur. The Company may also enter into foreign exchange contracts that are not designated as hedging instruments for financial accounting purposes. These contracts are generally entered into to offset the gains and losses on certain asset and liability balances until the expected time of repayment. Accordingly, any gains or losses resulting from changes in the fair value of the non-designated contracts are reported in other income (expense), net in the consolidated statements of comprehensive loss. The gains and losses on these contracts generally offset the gains and losses associated with the underlying foreign currency-denominated balances, which are also reported in other income (expense), net. The Company records the assets or liabilities associated with derivative instruments and hedging activities at fair value based on Level 2 inputs in other current assets or other current liabilities, respectively, in the consolidated balance sheets. The Company had a related payable of $ 155 and $ 422 as of December 31, 2023 and 2022, respectively. F- 13 The Company documents the hedging relationship and its risk management objective and strategy for undertaking the hedge, the hedging instrument, the hedged transaction, the nature of the risk being hedged, how the hedging instrument’s effectiveness in offsetting the hedged risk will be assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Company assesses hedge effectiveness and ineffectiveness at a minimum quarterly but may assess it monthly. For derivative instruments that are designed and qualify as part of a cash flow hedging relationship, the effective portion of the gain or loss on the derivative is reported in other comprehensive loss and reclassified into earnings in the same periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current period earnings. The Company will discontinue hedge accounting prospectively when it determines that the derivative is no longer effective in offsetting cash flows attributable to the hedge risk. The cash flow hedge is de-designated because a forecasted transaction is not probable of occurring, or management determines to remove the designation of the cash flow hedge. In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Company continues to carry the derivative at its fair value on the balance sheets and recognizes any subsequent changes in the fair value in earnings. When it is probable that a forecasted transaction will not occur, the Company will discontinue hedge accounting and recognize immediately in earnings gains and losses that were accumulated in other comprehensive loss related to the hedging relationship. Fair value of accumulated other comprehensive income (loss) The components of accumulated other comprehensive income (loss) were as follows: As of December 31, 2023 Foreign Unrealized Unrealized Accumulated currency gains gains (losses) other translation on marketable on cash comprehensive adjustments securities flow hedges income (loss) Balance as of December 31, 2022 $ ( 269 ) $ 26 $ — $ ( 243 ) Other comprehensive income 1,358 110 — 1,468 Balance as of December 31, 2023 $ 1,089 $ 136 $ — $ 1,225 As of December 31, 2022 Foreign Unrealized Unrealized Accumulated currency gains gains (losses) other translation on marketable on cash comprehensive adjustments securities flow hedges income (loss) Balance as of December 31, 2021 $ 328 $ 1 $ 1,140 $ 1,469 Other comprehensive income (loss) ( 597 ) 25 ( 1,140 ) ( 1,712 ) Balance as of December 31, 2022 $ ( 269 ) $ 26 $ — $ ( 243 ) Comprehensive income (loss) is the total net earnings and all other non-owner changes in equity. Except for net income (loss) and unrealized gains and losses on cash flow hedges, the Company does not have any transactions or other economic events that qualify as comprehensive income (loss). Fair value of earnout liability The earnout liability will be adjusted to fair value at each reporting date until settled. At the end of each reporting period after the acquisition date, the arrangement is remeasured at its fair value, with changes in fair value recorded in earnings. Changes in fair value will be recognized in general and administrative expense. The Company has obligations to pay up to $ 13,000 and $ 31,400 in earnout payments for the Physio-Assist acquisition and the New Aera acquisition, respectively, in cash if certain future financial and regulatory results are met. The earnout liabilities were valued using Level 3 inputs. F- 14 The fair value of the New Aera earnout was determined historically by employing a Monte Carlo simulation in a risk-neutral framework. The underlying simulated variable includes recognized revenue. The recognized revenue volatility estimate was based on a study of historical asset volatility for a set of comparable public companies. The model included other assumptions including the market price of risk, which was calculated as the weighted average cost of capital less the long-term risk-free rate. The earnout period for recognized revenue is each calendar year beginning with calendar year 2019 and ending on the calendar year in which the earnout consideration equals the earnout cap. As a result of the earnout requirements not expected to be met for New Aera due to the asset disposal, the Company considered the fair value measurement of the earnout liability to be $ 0 as of December 31, 2023 and 2022. Additional information on the loss on disposal of intangible asset contained later in this Note in Long-lived assets . The fair value of the Physio-Assist earnout was valued using a probability weighted expected return methodology and was discounted using a rate and probability that appropriately captures the risk associated with the achievement of one of two milestones related to FDA de novo authorization or 510(k) clearance for the Simeox Airway Clearance System within four years of the date of the closing of the transaction. Significant increases or decreases in these inputs could result in a significant impact on our fair value measurement. The reconciliation of the earnout liabilities measured and carried at fair value on a recurring basis is as follows: Balance as of December 31, 2021 $ 16,016 Change in fair value ( 16,016 ) Balance as of December 31, 2022 $ — Addition for acquisition 3,178 Change in fair value 6,822 Balance as of December 31, 2023 $ 10,000 Cash, cash equivalents, and marketable securities The Company considers all short-term highly liquid investments with a maturity of three months or less to be cash equivalents. The Company’s marketable debt securities are classified and accounted for as available-for-sale. Cash equivalents are recorded at cost plus accrued interest, which is considered adjusted cost, and approximates fair value. Marketable debt securities are included in cash equivalents and marketable securities based on the maturity date of the security. The Company considers investments with maturities greater than three months, but less than one year, to be marketable securities. Investments are reported at fair value with realized and unrealized gains or losses reported in other income (expense), net. The Company reviews its investments to identify and evaluate investments that have an indication of possible impairment. Factors considered in determining whether a loss is temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company's intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. Expected credit losses are declines in fair value that are not expected to recover and are charged to other income (expense), net. Accounts receivable Accounts receivable are customer obligations due under normal sales and rental terms. The Company performs credit evaluations of the customers’ financial condition and generally does not require collateral. The allowance for doubtful accounts is maintained at a level that, in management’s opinion, is adequate to absorb potential losses related to accounts receivable and is based upon the Company’s continuous evaluation of the collectability of outstanding balances. Management’s evaluation takes into consideration such factors as past bad debt experience, economic conditions and information about specific receivables. The Company’s evaluation also considers the age and composition of the outstanding amounts in determining their net realizable value. The allowance for doubtful accounts is based on estimates, and ultimate losses may vary from current estimates. As adjustments to these estimates become necessary, they are reported in general and administrative expense for sales revenue in the periods in which they become known. The allowance is increased by bad debt provisions, net of recoveries, and is reduced by direct write-offs. The Company generally does not allow returns from providers for reasons not covered under its standard warranty. Therefore, provision for returns applies primarily to direct-to-consumer sales. This reserve is calculated primarily based on actual historical return rates under the Company’s 30-day return program and is applied to the related sales revenue for the last month of the quarter reported. F- 15 The Company also records an estimate for rental revenue adjustments which is recorded as a reduction of rental revenue and net rental accounts receivable balances. These adjustments result from contractual adjustments, audit adjustments, untimely claims filings, or billings not paid due to another provider performing same or similar functions for the patient in the same period, all of which prevent billed revenue from becoming realizable. The reserve is based on historical revenue adjustments as a percentage of rental revenue billed and unbilled during the related period. When recording the allowance for doubtful accounts for sales revenue, the bad debt expense account (general and administrative expense account) is charged and when recording allowance for sales returns, the sales returns account (contra sales revenue account) is charged. The Company consistently applies its allowance estimation methodology from period-to-period. The Company’s best estimate is made on an accrual basis and adjusted in future periods as required. Any adjustments to the prior period estimates are included in the current period. As additional information becomes known, the Company adjusts its assumptions accordingly to change its estimate of accounts receivable. For the years ended December 31, 2023 and December 31, 2022 , the Company had increases of $ 1,055 and $ 1,483 , respectively, in the net rental revenue related to prior years. Net accounts receivable (gross accounts receivable, net of allowances) balance concentrations by major category as of December 31, 2023 and December 31, 2022 were as follows: As of As of December 31, 2023 December 31, 2022 Net accounts receivable $ % $ % Rental (1) $ 6,401 15.2 % $ 5,246 8.4 % Business-to-business and other receivables (2) 35,840 84.8 % 57,479 91.6 % Total net accounts receivable $ 42,241 100.0 % $ 62,725 100.0 % (1) Rental includes Medicare, Medicaid/other government, private insurance and patient pay. (2) Business-to business receivables included extended terms for two customers: 1) one customer had a net accounts receivable balance of $ 8,639 and $ 22,641 as of December 31, 2023 and December 31, 2022 , respectively; and 2) one customer had a net accounts receivable balance of $ 4,994 and $ 9,861 as of December 31, 2023 and December 31, 2022, respectively. Each customer received extended payment terms through a direct financing plan offered. The following table sets forth the percentage breakdown of the Company’s net accounts receivable by aging category and invoice due date as of December 31, 2023 and December 31, 2022. As of As of December 31, 2023 December 31, 2022 Net accounts receivable by aging category $ % $ % Held and Unbilled $ 1,388 3.3 % $ 303 0.5 % Aged 0-90 days 32,020 75.8 % 61,556 98.1 % Aged 91-180 days 8,222 19.5 % 565 0.9 % Aged 181-365 days 574 1.4 % 287 0.5 % Aged over 365 days 37 0.0 % 14 0.0 % Total net accounts receivable $ 42,241 100.0 % $ 62,725 100.0 % The following table sets forth the accounts receivable allowances as of December 31, 2023 and December 31, 2022: As of As of December 31, 2023 December 31, 2022 Allowances - accounts receivable $ % $ % Doubtful accounts $ 2,341 5.2 % $ 77 0.1 % Sales returns 479 1.1 % 483 0.8 % Total allowances - accounts receivable $ 2,820 6.3 % $ 560 0.9 % F- 16 Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash, cash equivalents, marketable securities and accounts receivable. At times, cash account balances may be in excess of the amounts insured by the Federal Deposit Insurance Corporation. However, management believes the risk of loss to be minimal. The Company performs periodic evaluations of the relative credit standing of these institutions and has not experienced any losses on its cash and cash equivalents to date. The Company has also entered into hedging relationships with a single counterparty to offset the forecasted Euro-based revenues. The credit risk has been reduced due to a net settlement arrangement whereby the Company is allowed to net settle transactions with a single net amount payable by one party to the other. Concentration of customers and vendors The Company primarily sells its products to traditional home medical equipment providers, distributors, and resellers in the United States and in foreign countries on a credit basis. The Company also sells its products direct-to-consumers primarily on a prepayment basis. Medicare's service reimbursement programs represented more than 10% of the Company’s total revenue for the years ended December 31, 2023 , 2022 and 2021. Two customers each represented more than 10% of the Company's net accounts receivable balance with net accounts receivable balances of $ 8,639 and $ 4,994 , respectively, as of December 31, 2023 and $ 22,641 and $ 9,861 , respectively, as of December 31, 2022. The Company also rents products directly to consumers for insurance reimbursement, which resulted in a customer concentration relating to Medicare’s service reimbursement programs. Medicare’s service reimbursement programs accounted for 67.7 %, 77.0 % and 81.9 % of rental revenue in 2023, 2022 and 2021 , respectively, and based on total revenue were 13.7 %, 11.6 % and 10.6 % for 2023, 2022 and 2021 , respectively. Accounts receivable balances relating to Medicare’s service reimbursement programs (including held and unbilled, net of allowances) amounted to $ 2,059 or 4.9 % of total net accounts receivable as of December 31, 2023 compared to $ 2,138 or 3.4 % of total net accounts receivable as of December 31, 2022. The Company currently purchases raw materials from a limited number of vendors, which resulted in a concentration of three major vendors. The three major vendors supply the Company with raw materials used to manufacture the Company’s products. For the year ended December 31, 2023 , the Company’s three major vendors accounted for 30.8 %, 16.1 % and 7.9 %, respectively, of total raw material purchases. For the year ended December 31, 2022 , the Company’s three major vendors accounted for 28.1 %, 17.7 % and 8.0 %, respectively, of total raw material purchases. A portion of revenue is earned from sales outside the United States. Approximately 77.7 %, 70.9 % and 74.1 % of the non-U.S. revenue for the years ended December 31, 2023, 2022 and 2021, respectively, were invoiced in Euros. A breakdown of the Company’s revenue from U.S. and non-U.S. sources for the years ended December 31, 2023, 2022 and 2021, respectively, is as follows: Years ended December 31, 2023 2022 2021 U.S. revenue $ 226,259 $ 276,078 $ 278,543 Non-U.S. revenue 89,401 101,163 79,460 Total revenue $ 315,660 $ 377,241 $ 358,003 F- 17 Inventories Inventories are stated at the lower of cost and net realizable value, using the first-in, first-out (FIFO) method. The Company records adjustments to inventory for potentially excess, obsolete, slow-moving or impaired items, and losses on firm purchase commitments as a component of cost of sales in our consolidated statements of comprehensive loss. The Company recorded noncurrent inventory related to inventories that are expected to be realized or consumed after one year of $ 1,225 and $ 1,249 as of December 31, 2023 and 2022, respectively. Noncurrent inventories are primarily related to raw materials purchased in bulk to support long-term expected repairs to reduce costs and are classified in other assets. The Company had prepayments for raw materials of $ 0 and $ 7,017 as of December 31, 2023 and 2022, respectively, that were classified in prepaid expenses and other current assets. During the years ended December 31, 2023, 2022 and 2021 , $ 2,187 , $ 1,221 and $ 906 , respectively, of inventory was transferred to rental equipment and was considered a noncash transaction in the production and purchase of rental equipment on the consolidated statements of cash flows. Inventories that are considered current consist of the following: December 31, 2023 2022 Raw materials and work-in-progress $ 18,036 $ 26,496 Finished goods 6,871 9,324 Less: reserves ( 3,067 ) ( 1,727 ) Inventories, net $ 21,840 $ 34,093 Property and equipment Property and equipment are stated at cost. Depreciation and amortization are calculated using the straight-line method over the assets’ estimated useful lives as follows: Rental equipment 1.5 - 8 years Manufacturing equipment and tooling 3 - 5 years Computer equipment and software 2 - 3 years Furniture and equipment 3 - 5 years Leasehold improvements Lesser of estimated useful life or remaining lease term Expenditures for additions, improvements and replacements are capitalized and depreciated to a salvage value of $ 0 . Repair and maintenance costs on rental equipment are included in cost of rental revenue on the consolidated statements of comprehensive loss. Repair and maintenance expense, which includes labor, parts and freight, for rental equipment was $ 5,143 , $ 4,528 and $ 3,387 for the years ended December 31, 2023, 2022 and 2021, respectively. Included within property and equipment is construction in process, primarily related to the design and engineering of tooling, jigs and other machinery. In addition, this item also includes computer software or development costs that have been purchased but have not completed the final configuration process for implementation into the Company’s systems. These items have not been placed in service; therefore, no depreciation or amortization was recognized for these items in the respective periods. Depreciation and amortization expense related to rental equipment and other property and equipment are summarized below for the years ended December 31, 2023, 2022 and 2021, respectively. Years ended December 31, 2023 2022 2021 Rental equipment $ 12,893 $ 11,103 $ 8,860 Other property and equipment 4,057 3,942 3,993 Total depreciation and amortization $ 16,950 $ 15,045 $ 12,853 F- 18 Property and equipment and rental equipment with associated accumulated depreciation is summarized below as of December 31, 2023 and 2022, respectively. December 31, Property and equipment 2023 2022 Rental equipment, net of allowances of $ 2,606 and $ 2,255 , respectively $ 67,804 $ 61,679 Other property and equipment 30,357 33,434 Property and equipment $ 98,161 $ 95,113 Accumulated depreciation Rental equipment $ 31,023 $ 31,320 Other property and equipment 16,822 20,524 Accumulated depreciation $ 47,845 $ 51,844 Property and equipment, net Rental equipment, net of allowances of $ 2,606 and $ 2,255 , respectively $ 36,781 $ 30,359 Other property and equipment 13,535 12,910 Property and equipment, net $ 50,316 $ 43,269 Long-lived assets The Company accounts for the impairment and disposition of long-lived assets in accordance with ASC 360 — Property, Plant, and Equipment . Long-lived assets are reviewed for indicators of impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. The evaluation is performed at the lowest level of identifiable cash flows, which is at the individual asset level or the asset group level. The undiscounted cash flows expected to be generated by the related assets are estimated over their useful life based on updated projections. If the evaluation indicates that the carrying amount of the assets may not be recoverable, any potential impairment is measured based upon the fair value of the related assets or asset group as determined by an appropriate market appraisal or other valuation technique. Assets classified as held for sale, if any, are recorded at the lower of carrying amount or fair value less costs to sell. During the year ended December 31, 2023, the Company determined that an impairment indicator was present related to negative cash flows and a decrease in the Company’s public stock price that caused the Company's market capitalization to fall below its carrying amount (stockholders' equity). The relevant long-lived asset grouping was evaluated for impairment. An undiscounted cash flow analysis demonstrated sufficient undiscounted cash flows in excess of the asset group’s carrying value. Estimates and significant assumptions included in the long-lived asset impairment analysis included identification of the asset group and undiscounted cash flow projections. The Company concluded that its definite-lived intangible assets and long-lived assets were not impaired based on the results of the quantitative analyses performed. On December 19, 2022, the Company determined to dispose of the technology intangible assets previously acquired from New Aera related to the Tidal Assist ® Ventilator (TAV ® ) technology by ceasing development of such assets and abandoning the TAV program (the Disposal Determination). Prior to December 19, 2022, the TAV intangible asset was held and used, including ongoing research and development and no significant revenue. The Company made the Disposal Determination based on the Company’s assessment that continued development of the assets would not be economically feasible. The assessment considered many factors, including 1) the lack of compatibility and functionality of the technology intangible asset within the Company’s existing product portfolio, 2) the lack of commercial potential of such products that were not approved for ventilation Medicare reimbursement and a negative litigation outcome that occurred subsequent to the approved coding process, and 3) the substantial additional investment that would be required in order to attempt to achieve any commercial potential with substantial risk that no benefit would ever be achievable. There had been no significant revenue associated with the sale of products developed from the technology intangible asset acquired from New Aera to date and the Company does not expect any revenue from such products going forward. Upon abandonment, the Company recognized a loss on disposal of $ 52,161 in our consolidated statements of comprehensive loss for the year ended December 31, 2022 for intangible assets, inventories, fixed assets, and construction in process associated with the TAV technology. As a result of no future sales, the fair value of the earnout resulted in a benefit of $ 13,687 to general and administrative expense during the fourth quarter of 2022. F- 19 During the year ended December 31, 2021, the Company determined that an impairment indicator was present related to TAV developments as a result of the court order to dismiss the Company’s preliminary injunction related to the Department of Health and Human Services and the Centers for Medicare and Medicaid Services lawsuit. The relevant long-lived asset grouping was evaluated for impairment. An undiscounted cash flow analysis demonstrated sufficient undiscounted cash flows in excess of the asset group’s carrying value. Estimates and significant assumptions included in the long-lived asset impairment analysis included identification of the asset group and undiscounted cash flow projections. The Company concluded that its definite-lived intangible assets and long-lived assets were not impaired based on the results of the quantitative analyses performed. Goodwill and other identifiable intangible assets Goodwill represents the excess acquisition cost over the fair value of the net tangible and intangible assets acquired. Goodwill is not amortized and is tested for impairment on an annual basis as of October 1 or whenever an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit or asset below its carrying amount. If the carrying amount of goodwill exceeds the implied estimated fair value, an impairment charge to current operations is recorded to reduce the carrying value to the implied estimated fair value. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value is less than its carrying amount. If, based on a review of qualitative factors, it is more likely than not that the fair value is less than its carrying amount, the Company will use a quantitative approach, and calculate the fair value and compare it to its carrying amount. If the fair value exceeds the carrying amount, there is no indication of impairment. If the carrying amount exceeds the fair value, an impairment loss is recorded equal to the difference. Finite-lived intangible assets are amortized over their useful lives and are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Technology and customer relationships are amortized using the straight-line method. Business combinations The results of operations of the businesses acquired by the Company are included as of the acquisition date. The purchase price of an acquisition is allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. To the extent the purchase price exceeds the fair value of the net identifiable tangible and intangible assets acquired and liabilities assumed, such excess is allocated to goodwill. The Company may adjust the preliminary purchase price allocation, as necessary, for up to one year after the acquisition closing date if it obtains more information regarding asset valuations and liabilities assumed. Acquisition-related expenses are recognized separately from the business combination and are expensed as incurred. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (ROU) assets, operating lease liability – current, and operating lease liability – noncurrent on the consolidated balance sheets. 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 at commencement date based on the present value of lease payments over the lease term. The Company uses an incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments as the rate implicit in each lease is generally not readily determinable. The operating lease ROU asset also includes any lease payments made to the lessor at or before the commencement date and excludes lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components. The Company elected the practical expedient to treat the lease and non-lease components as a single lease component. Additionally, the Company elected the practical expedient to not record leases with an initial term of twelve months or less on the consolidated balance sheets. F- 20 Loss contingencies The Company is involved in various lawsuits, claims, investigations, and proceedings that arise in the ordinary course of business. The Company records a liability when it believes that it is both probable that a loss has been incurred and the amount can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount. The Company reviews at least quarterly and adjusts accordingly to reflect the impact of negotiations, settlements, rulings, advice of legal counsel, and updated information. Research and development Research and development costs are expensed as incurred. Advertising costs Advertising costs, which approximated $ 27,120 , $ 33,265 and $ 35,183 during the years ended December 31, 2023, 2022 and 2021 , respectively, are expensed as incurred, excluding the production costs of direct response advertising. Advertising costs are included in sales and marketing expense in the accompanying consolidated statements of comprehensive loss. Restructuring charges Restructuring costs include workforce reductions, termination benefits, office downsizing, centralizing manufacturing activities, and equipment relocation. Key assumptions used in calculating the restructuring costs include the terms of, and payments under, agreements to terminate certain contractual obligations and the timing of reductions in workforce. Income taxes The Company accounts for income taxes in accordance with ASC 740 — Income Taxes . Under ASC 740, income taxes are recognized for the amount of taxes payable or refundable for the current period and deferred tax liabilities and assets are recognized for the future tax consequences of transactions that have been recognized in the Company’s consolidated financial statements or tax returns. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is provided when it is more likely than not that some portion, or all, of the deferred tax asset will not be realized. The Company accounts for uncertainties in income taxes in accordance with ASC 740-10 — Accounting for Uncertainty in Income Taxes . ASC 740-10 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. This accounting standard also provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company recognizes interest and penalties on taxes, if any, within its income tax provision on its consolidated statements of comprehensive loss. Accounting for stock-based compensation The Company accounts for its stock-based compensation in accordance with ASC 718 — Compensation—Stock Compensation , which establishes accounting for share-based awards, exchanged for employee services and requires companies to expense the estimated fair value of these awards over the requisite employee service period. Stock–based compensation cost for stock options and employee stock purchase plan are determined at the grant date using the Black-Scholes option pricing model. Stock-based compensation cost for stock incentive awards is based on the number of shares ultimately expected to vest, estimated at each reporting date based on management’s expectations regarding the relevant performance criteria. The value of the award that is ultimately expected to vest is recognized as expense on a straight-line basis over the employee’s requisite service period. As part of the provisions of ASC 718, the Company is required to estimate potential forfeitures of stock grants and adjust compensation cost recorded accordingly. The estimate of forfeitures will be adjusted over the requisite service period to the extent that actual forfeitures differ, or are expected to differ, from such estimates. Changes in estimated forfeitures will be recognized through a cumulative catch-up adjustment in the period of change and will also impact the amount of stock compensation expense to be recognized in future periods. F- 21 Foreign currency The functional currency of the Company’s international subsidiaries is the local currency. The financial statements of the subsidiaries are translated to U.S. dollars using month-end exchange rates for assets and liabilities and average exchange rates for revenue, cost of revenue, operating expense and provision for income taxes. Translation gains and losses are recorded in accumulated other comprehensive income (loss) as a component of stockholders’ equity. Foreign exchange transaction gains and losses resulting from the conversion of the transaction currency to functional currency are reflected as a component of foreign currency exchange gains or losses in other income (expense), net in the consolidated statements of comprehensive loss. Business segments The Company operates and reports in only one operating and reportable segment – development, manufacturing, marketing, sales, and rental of respiratory products. Management reports financial information on a consolidated basis to the Company’s chief operating decision maker. Loss per share Loss per share (EPS) is computed in accordance with ASC 260 — Earnings per Share and is calculated using the weighted-average number of common shares outstanding during each period. Diluted EPS assumes the conversion, exercise or issuance of all potential common stock equivalents (which can include dilution of outstanding stock options, restricted stock units and restricted stock awards) unless the effect is to reduce a loss or increase the income per share. For purposes of this calculation, common stock subject to repurchase by the Company, options, and other dilutive awards are considered to be common stock equivalents and are only included in the calculation of diluted loss per share when their effect is dilutive. Basic loss per share is calculated using the Company’s weighted-average outstanding common shares. Diluted loss per share is calculated using the Company’s weighted-average outstanding common shares including the dilutive effect of stock awards as determined under the treasury stock method. The computation of EPS is as follows: Years ended December 31, 2023 2022 2021 Numerator—basic and diluted: Net loss $ ( 102,449 ) $ ( 83,772 ) $ ( 6,333 ) Denominator: Weighted average common shares - basic common stock (1) 23,176,098 22,852,571 22,490,027 Weighted average common shares - diluted common stock 23,176,098 22,852,571 22,490,027 Net loss per share - basic common stock $ ( 4.42 ) $ ( 3.67 ) $ ( 0.28 ) Net loss per share - diluted common stock (2) $ ( 4.42 ) $ ( 3.67 ) $ ( 0.28 ) Denominator calculation from basic to diluted: Weighted average common shares - basic common stock (1) 23,176,098 22,852,571 22,490,027 Stock options and other dilutive awards 160,682 115,155 166,258 Weighted average common shares - diluted common stock 23,336,780 22,967,726 22,656,285 Shares excluded from diluted weighted-average shares: Stock options 104,681 329,586 151,344 Restricted stock units and restricted stock awards 926,859 528,398 167,237 Shares excluded from diluted weighted average shares 1,031,540 857,984 318,581 (1) Unvested restricted stock units and restricted stock awards are not included as shares outstanding in the calculation of basic earnings per share. Vested restricted stock units and restricted stock awards are included in basic earnings per share if all vesting and performance criteria have been met. Performance-based restricted stock units and restricted stock awards are included in the number of shares used to calculate diluted earnings per share as long as all applicable performance criteria are met, and their effect is dilutive. Restricted stock awards are eligible to receive all dividends declared on the Company’s common shares during the vesting period; however, such dividends are not paid until the restrictions lapse. (2) Due to net losses for the years ended December 31, 2023, 2022 and 2021 , diluted loss per share is the same as basic. F- 22 Recently issued accounting pronouncements not yet adopted In November 2023, the FASB issued the Accounting Standards Update (ASU) No. 2023-09, Segment Reporting (Topic 280):Improvements to Reportable Segment Disclosures . The new guidance expands annual and interim disclosure requirements for reportable segments, primarily through enhanced disclosures about significant segment expenses. The ASU is effective for fiscal years beginning after January 1, 2024, and for interim periods beginning January 1, 2025, with early adoption permitted. The Company is currently evaluating the effect of the new guidance but does not expect it to have a material impact on the Company’s consolidated financial statement presentation or results. In December 2023, the FASB issued the ASU No. 2023-09, Improvements to Income Tax Disclosures . The new guidance requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. The standard is intended to benefit investors by providing more detailed income tax disclosures that would be useful in making capital allocation decisions. The ASU is effective for fiscal years beginning after December 15, 2025, and interim periods within those years, with early adoption permitted. The Company is currently evaluating the effect of the new guidance but does not expect it to have a material impact on the Company’s consolidated financial statement presentation or results. 3. Acquisitions On July 10, 2023, the Company entered into a share purchase agreement to acquire Physio-Assist, which is in the business of the design, production, and marketing of medical devices for bronchial decongestion (airway clearance technique) for patients suffering from obstructive respiratory diseases. On September 14, 2023, the Company completed the acquisition of all of the issued and outstanding capital stock of Physio-Assist and its wholly-owned subsidiary PhysioAssist GmbH for a purchase price consisting of $ 32,250 in cash consideration and the fair value of a potential earnout of $ 3,178 based on future regulatory clearances. The Company incurred acquisition-related expenses of approximately $ 1,860 in the twelve months ended December 31, 2023, which were recorded within general and administrative expense. A potential earnout payment of either $ 13,000 (without a clinical trial requirement) or $ 11,000 (with a required clinical trial less related development costs) is dependent upon the achievement of one of two milestones related to the FDA de novo authorization or 510(k) clearance for the Simeox Airway Clearance System within four years of the date of the closing of the transaction. The fair value of the earnout liability was measured using the probability weighted expected return methodology and was discounted using a rate and probability that appropriately captures the risk associated with the obligation. The acquisition was treated as a business combination. Assets and liabilities of the acquired company were recorded at their estimated fair values at the date of acquisition. The excess purchase price over the fair value of net tangible assets and identifiable intangible assets acquired has been allocated to goodwill. Goodwill represents the expected synergies with the existing business, the acquired assembled workforce, and future cash flows after the acquisition. The fair value assigned to the identifiable intangible assets was determined primarily by using the excess earnings method. The key assumptions included in the excess earnings method included revenue recognized, cost of revenue, and the discount rate. The Company’s allocation of the purchase price of Physio-Assist is preliminary and any measurement period adjustments that result from the finalization of the purchase price allocation will be recorded retrospectively to the acquisition date. Changes are possible and could change the allocation of the purchase price. F- 23 The following table summarizes the preliminary allocation of the purchase price over the estimated fair value of the assets acquired and liabilities assumed in the acquisition of Physio-Assist: Cash $ 2,617 Accounts receivable 184 Inventories 296 Other assets 325 Property and equipment 82 Operating lease right-of-use asset 306 Intangible assets 34,100 Goodwill 9,755 Total assets acquired $ 47,665 Accounts payable and accrued expenses $ 1,108 Bank loans 1,922 Other current liabilities 376 Operating lease liability 306 Deferred tax liability - noncurrent 8,525 Total liabilities assumed $ 12,237 Total identifiable net assets $ 35,428 Cash consideration $ 32,250 Fair value of contingent earnout consideration 3,178 Total purchase price $ 35,428 Included in the acquired intangible assets were $ 32,300 of developed technology, $ 1,600 of customer relationships, and $ 200 related to trade name. The fair value measurements of the intangibles were based primarily on Level 3 inputs. Certain working capital accounts such as accounts receivables, inventories, other current assets, accounts payable and accrued expenses, bank loans and other current liabilities, as well as intangibles and related income tax amounts may be adjusted subsequent to the acquisition as they are realized at different values. These changes would be reflected as measurement period adjustments. All of the bank loans were settled subsequent to the acquisition date and prior to December 31, 2023. The consolidated financial and operating results reflect the Physio-Assist operations beginning September 14, 2023. The following unaudited pro forma information for the twelve months ended December 31, 2023 and 2022 presents the revenues and net loss assuming the acquisition of Physio-Assist had occurred as of January 1, 2022. Twelve months ended December 31, 2023 2022 Total revenue $ 318,737 $ 379,305 Net loss $ ( 105,230 ) $ ( 87,079 ) 4. Goodwill and other identifiable intangible assets Goodwill The changes in the carrying amount of goodwill for the years ended December 31, 2023 and 2022 were as follows: Balance as of December 31, 2021 $ 32,979 Translation adjustment ( 127 ) Balance as of December 31, 2022 $ 32,852 Translation adjustment 344 Impairment charge ( 32,894 ) Acquisition 9,755 Balance as of December 31, 2023 $ 10,057 F- 24 As a result of a decrease in Company’s public stock price that caused the Company's market capitalization to fall below its carrying amount (stockholders' equity) during July 2023 and noted by management to be more than temporary as the quarter progressed, a quantitative analysis was required to be performed during the quarter ended September 30, 2023. The Company used a discounted cash flow analysis based on Level 3 inputs and determined that the goodwill carrying amount exceeded its fair value and, as such, an impairment charge of $ 32,894 was incurred in the quarter ended September 30, 2023. Accumulated impairment losses were $ 32,894 for the year ended December 31, 2023. The Company performed an assessment of qualitative factors and determined that no events or circumstances existed that would lead to a determination that it is more likely than not that the fair value of indefinite-lived assets were less than the carrying amount. As a result of the TAV technology intangible asset disposal, a quantitative analysis was required to be performed as of December 31, 2022 and concluded that there was no impairment. Intangible assets There were no impairment losses related to the Company’s intangible assets as of December 31, 2023 and 2022 . Amortization expense for intangible assets for the years ended December 31, 2023, 2022 and 2021 was as follows: Years ended December 31, 2023 2022 2021 Research and development expense $ 986 $ 7,813 $ 7,813 Sales and marketing expense 155 116 181 General and administrative expense 61 540 781 Total $ 1,202 $ 8,469 $ 8,775 I ntangible assets as of December 31, 2023 and 2022 consisted of the following: Average estimated Gross useful lives carrying Accumulated December 31, 2023 (in years) amount amortization Net amount Developed technology 10 $ 33,303 $ 971 $ 32,332 Licenses 10 185 185 — Patents and websites 5 4,518 4,429 89 Customer relationships 4 2,974 1,372 1,602 Trade name 4 206 15 191 Commercials 3 494 117 377 Total $ 41,680 $ 7,089 $ 34,591 Average estimated Gross useful lives carrying Accumulated December 31, 2022 (in years) amount amortization Net amount Licenses 10 $ 185 $ 183 $ 2 Patents and websites 5 4,514 4,353 161 Customer relationships 4 1,284 1,284 — Commercials 2 - 3 256 242 14 Total $ 6,239 $ 6,062 $ 177 F- 25 Annual estimated amortization expense for each of the succeeding fiscal years is as follows: December 31, 2023 2024 $ 4,026 2025 3,978 2026 3,846 2027 3,731 2028 3,330 Thereafter 15,680 Total $ 34,591 5. Current liabilities Accounts payable and accrued expenses as of December 31, 2023 and 2022 consisted of the following: December 31, 2023 2022 Accounts payable $ 13,454 $ 18,237 Accrued inventory (in-transit and unvouchered receipts) and trade payables 10,054 10,837 Accrued purchasing card liability 2,197 2,606 Accrued loss on purchase commitments 2,057 — Accrued franchise, sales and use taxes 472 492 Other accrued expenses 1,908 1,802 Total accounts payable and accrued expenses $ 30,142 $ 33,974 Accrued payroll as of December 31, 2023 and 2022 consisted of the following: December 31, 2023 2022 Accrued bonuses $ 1,110 $ 2,620 Accrued wages and other payroll related items 4,170 4,967 Accrued vacation 3,194 3,133 Accrued severance 2,284 — Accrued employee stock purchase plan deductions 308 470 Total accrued payroll $ 11,066 $ 11,190 6. Leases The Company has entered into operating leases primarily for commercial buildings. These leases have terms which range from 3 years to 11 years, some of which include options to extend the leases for up to 5 years. Rent expense, including short-term lease cost, was $ 4,017 , $ 3,870 , and $ 4,095 for the years ended December 31, 2023, 2022 and 2021, respectively. Operating lease right-of-use assets and liabilities commencing after January 1, 2019 are recognized at commencement date based on the present value of lease payments over the lease term. The operating leases do not contain material residual value guarantees or material restrictive covenants. In July 2023, the Company entered into an Assignment and Assumption of Lease Agreement in which a third party (Assignee) assumed the rights, title, and interest in the lease, including assumption of lease payments. As inducement for the Assignee to enter into the agreement, the Company paid an incentive of $ 395 , provided for four months of free rent for the period October 1, 2023 through January 31, 2024, and conveyed ownership of certain items of the facility's furniture and equipment. Commencing February 1, 2024 and ending May 31, 2031, the Assignee assumes responsibility for the monthly lease payments. Notwithstanding the Assignee's assumption of lease payments, Inogen remains the primary obligor under the lease to the landlord. The Assignee gained control to the facility on September 29, 2023, and related sublease income was not material. F- 26 Lease payments assumed by the Assignee are: Payments due in the 12-month period ending December 31, 2024 $ 1,041 2025 1,136 2026 1,136 2027 1,136 2028 1,136 Thereafter 2,745 $ 8,330 Information related to the Company’s right-of-use assets and related operating lease liabilities were as follows: Year ended Year ended December 31, 2023 December 31, 2022 Cash paid for operating lease liabilities $ 4,044 $ 3,964 Operating lease cost 3,979 3,828 Non-cash right-of-use assets obtained in exchange for new operating lease obligations 1,781 225 Weighted-average remaining lease term 2.9 years 2.3 years Weighted-average discount rate 4.5 % 2.9 % Maturities of lease liabilities due in the 12-month period ending December 31, 2024 $ 4,162 2025 3,271 2026 3,290 2027 3,313 2028 2,953 Thereafter 6,823 $ 23,812 Less imputed interest ( 1,889 ) Total lease liabilities $ 21,923 Operating lease liability - current $ 3,653 Operating lease liability - noncurrent 18,270 Total lease liabilities $ 21,923 7. Income taxes The components of the Company’s income (loss) before provision for income taxes are as follows: Years ended December 31, 2023 2022 2021 United States $ ( 99,015 ) $ ( 84,422 ) $ 7,621 Foreign ( 3,329 ) 1,154 1,038 Income (loss) before provision for income taxes $ ( 102,344 ) $ ( 83,268 ) $ 8,659 F- 27 The provision for income taxes consists of the following: Years ended December 31, Current tax expense 2023 2022 2021 Federal $ — $ — $ — State 229 201 271 Foreign 127 303 266 Total current tax expense $ 356 $ 504 $ 537 Deferred tax expense (benefit) Federal — — 10,263 State — — 4,194 Foreign ( 251 ) — ( 22 ) Total deferred tax expense (benefit) $ ( 251 ) $ — $ 14,435 Interest and penalties — — 20 Total deferred tax expense (benefit), net — — — Provision for income taxes $ 105 $ 504 $ 14,992 The components of deferred tax assets and liabilities consist of the following: As of December 31, Deferred tax assets (liabilities) 2023 2022 Accrued expenses $ 10,121 $ 10,600 Net operating loss and credit carryforward 41,195 27,824 Allowance, reserves and other 3,015 2,784 Stock-based compensation 5,809 4,042 Intangible amortization — 2,045 Lease liability 5,098 5,674 Capitalized R&D under Sec 174 6,257 2,915 Deferred tax assets $ 71,495 $ 55,884 Property, plant, and equipment ( 8,806 ) ( 8,674 ) Intangible amortization ( 6,528 ) — Right-of-use asset ( 4,732 ) ( 5,277 ) Deferred tax liabilities $ ( 20,066 ) $ ( 13,951 ) Valuation allowance ( 59,968 ) ( 41,933 ) Total $ ( 8,539 ) $ — Reconciliation of the federal statutory income tax rate to the effective income tax rate for the years ended December 31, 2023, 2022 and 2021 is as follows: Years ended December 31, 2023 2022 2021 U.S. Statutory rate 21.00 % 21.00 % 21.00 % State income taxes, net of federal benefit 1.43 % 3.53 % - 1.39 % Stock-based compensation - 0.66 % - 1.02 % - 21.72 % R&D credit, net of reserve 1.00 % 1.32 % - 5.95 % Change in fair value - 1.40 % 3.88 % - 28.19 % Nondeductible compensation - 0.09 % - 1.50 % 7.04 % Valuation allowance - 14.80 % - 27.75 % 201.69 % Goodwill impairment charge - 6.75 % — — Other 0.17 % - 0.07 % 0.63 % Effective income tax rate - 0.10 % - 0.61 % 173.11 % F- 28 The Company operates in several taxing jurisdictions, including U.S. federal, multiple U.S. states, Netherlands, France and Germany. The statute of limitations has expired for all tax years prior to 2020 for federal and prior to 2017 for various state tax purposes. The statute of limitations has expired for all tax years prior to 2021 for France, prior to 2020 for Germany, and prior to 2019 for Netherlands purposes. However, the net operating loss generated on the Company’s federal and state tax returns in prior years may be subject to adjustments by the federal and state tax authorities. As of December 31, 2023 , the Company had $ 126,771 , $ 66,039 and $ 10,851 of federal, state and foreign net operating loss carryforwards, respectively. Federal net operating loss carryforwards of $ 118,975 have an indefinite life while the remaining federal and state net operating loss carryforwards begin to expire in 2033 and 2028 , respectively, if not utilized. Foreign net operating loss carryforwards of $ 10,851 also have an indefinite life. As of December 31, 2023 , the Company had federal and California research and development credit carryforwards of $ 6,576 and $ 4,882 , respectively. The federal credit will begin to expire in 2024 ; the California credit has indefinite carryforward. As of December 31, 2023, the Company had a federal foreign tax credit carryforward of $ 774 . The federal credit will begin to expire in 2027 . Utilization of the Company’s net operating loss and tax credit carryforwards may be subject to annual limitations arising from ownership change limitations provided by the Internal Revenue Code and similar state and foreign provisions. Such annual limitations could result in the expiration of the net operating loss and tax credit carryforwards before their utilization. The Company recognizes deferred tax assets to the extent it believes these assets are more likely than not to be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. The amount of deferred tax assets considered realizable is subject to adjustment in future periods if estimates of future taxable income are reduced. As of December 31, 2023 and 2022, the Company determined that net deferred tax assets are not more likely than not realizable based on cumulative three-year pretax losses and recorded a full valuation allowance. The Company’s valuation allowance may increase or decrease during the next 12 months based on future operating results. The increase in valuation allowance of $ 18,035 is attributable to losses generated in the current year. The Company recognizes interest and penalties on taxes, within its income tax provision on its consolidated statements of comprehensive loss. Included in the balance of unrecognized tax benefits as of December 31, 2023, 2022 and 2021 , were $ 2,778 , $ 2,366 and $ 2,078 , respectively, of tax benefits that, if recognized, would affect the effective tax rate. The Company believes that there will be no significant increases or decreases to unrecognized tax benefits within the next 12 months. A reconciliation of the beginning and ending amount of unrecognized tax benefit is as follows: December 31, Reconciliation of liability for unrecognized tax benefits 2023 2022 2021 Balance at beginning of period $ 2,366 $ 2,078 $ 1,932 Additions based on tax positions related to current year 400 242 146 Reductions based on tax positions related to prior year ( 34 ) — — Additions based on tax positions related to prior year 46 46 — Balance at end of period $ 2,778 $ 2,366 $ 2,078 F- 29 8. Stockholders’ equity Common stock Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors, subject to the prior rights of holders of other classes of stock outstanding. Preferred stock Pursuant to the amended and restated certificate of incorporation filed by the Company in connection with the completion of its initial public offering, the Company’s board of directors is authorized to issue up to 10,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, redemption rights, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of common stock. The issuance of preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing change in the Company’s control or other corporate action. As of December 31, 2023 and 2022, no shares of preferred stock were issued or outstanding, and the board of directors has not authorized or designated any rights, preferences, privileges and restrictions for any class of preferred stock. Dividends There were no dividends declared during the years ended December 31, 2023, 2022 and 2021. Stock incentive plans The Company has a 2014 Equity Incentive Plan (2014 Plan) under which the Company granted restricted stock units, restricted stock awards, performance units, performance shares, and options to purchase shares of its common stock. As of December 31, 2023, awards with respect to 1,077,837 shares of the Company's common stock were outstanding. An additional 895,346 shares were added to the 2014 Plan share reserve in 2023. The Company’s stockholders approved the adoption of the 2023 Equity Incentive Plan (2023 Plan) on May 31, 2023 that provides for the grant of incentive stock options, within the meaning of Section 422 of the Internal Revenue Code, to the Company’s employees and any parent and subsidiary corporation’s employees, and for the grant of nonstatutory stock options, restricted stock, restricted stock units, restricted stock awards, stock appreciation rights, performance units, and performance shares to its employees, directors, and consultants and its parent and subsidiary corporations’ employees and consultants. The 2023 Plan became effective June 5, 2023. The 2014 Plan terminated upon effectiveness of the 2023 Plan and no further awards will be made under the 2014 Plan, but the 2014 Plan will continue to govern awards previously granted under it. The number of shares of common stock reserved for issuance under the 2023 Plan was: (i) 400,000 shares, plus (ii) (A) 2,027,790 shares that, as of immediately before the termination or expiration of the 2014 Plan, had been reserved but not issued under any 2014 Plan awards and are not subject to any awards granted under the 2014 Plan, plus (B) any shares subject to awards granted under the 2014 Plan or the 2012 Plan that, after the 2014 Plan is terminated or expired, expire or otherwise terminate without having been exercised or issued in full or are forfeited to or repurchased by the Company due to failure to vest, plus (C) any shares that, after the 2014 Plan is terminated or expired, are tendered to or withheld by us for payment of an exercise or purchase price or for tax withholding obligations with respe ct to an award granted under the 2014 Plan or 2012 Plan, with the maximum number of shares that may be added to the 2023 Plan under subsection (ii) above equal to 2,950,000 shares. As of December 31, 2023, 1,713,834 shares of common stock remained available for issuance under the 2023 Plan. The shares available for issuance under the 2023 Plan will be increased by any shares returned to the 2012 Plan and 2014 Plan as a result of 1) expiration or termination of awards and 2) tendered to or withheld by us for payment of an exercise or purchase price or for tax withholding obligations. Stock options Options typically expire between seven and ten years from the date of grant and vest over one to four-year terms. Options have been granted to employees, directors and consultants of the Company, as determined by the board of directors, at the deemed fair market value of the shares underlying the options at the date of grant. F- 30 The activity for stock options under the Company’s stock plans for the years ended December 31, 2023, 2022 and 2021 is as follows: Remaining weighted- Weighted- average Per share average contractual average Price per exercise terms intrinsic Options share price (in years) value Outstanding as of December 31, 2020 955,479 $ 0.75 -$ 83.30 $ 35.49 1.85 $ 11.81 Exercised ( 486,038 ) 0.75 - 46.66 28.19 Forfeited ( 10,000 ) 83.30 83.30 Outstanding as of December 31, 2021 459,441 1.17 - 83.30 42.18 1.36 4.31 Vested and exercisable as of December 31, 2021 459,441 1.17 - 83.30 42.18 1.36 4.31 Vested and expected to vest as of December 31, 2021 459,441 1.17 - 83.30 42.18 1.36 4.31 Outstanding as of December 31, 2021 459,441 1.17 - 83.30 42.18 1.36 4.31 Exercised ( 14,154 ) 1.17 - 8.37 3.14 Forfeited ( 15,417 ) 38.54 - 44.19 43.27 Expired ( 81,586 ) 38.54 - 43.21 40.08 Outstanding as of December 31, 2022 348,284 1.17 - 83.30 44.21 0.43 2.07 Vested and exercisable as of December 31, 2022 348,284 1.17 - 83.30 44.21 0.43 2.07 Vested and expected to vest as of December 31, 2022 348,284 1.17 - 83.30 44.21 0.43 2.07 Outstanding as of December 31, 2022 348,284 1.17 - 83.30 44.21 0.43 2.07 Exercised ( 54,432 ) 1.17 - 8.37 7.03 Forfeited ( 6,019 ) 8.37 - 44.19 32.92 Expired ( 267,833 ) 8.37 - 83.30 49.10 Outstanding as of December 31, 2023 20,000 83.30 83.30 0.36 — Vested and exercisable as of December 31, 2023 20,000 83.30 83.30 0.36 — Vested and expected to vest as of December 31, 2023 20,000 $ 83.30 $ 83.30 0.36 $ — The total intrinsic value of options exercised during the years ended December 31, 2023, 2022, and 2021 was $ 735 , $ 309 and $ 14,524 , respectively. As of December 31, 2023, all stock-based compensation expense for options granted under the Plans was recognized. Stock incentive awards The Company grants restricted stock units (RSUs) and restricted stock awards (RSAs) under the 2014 and 2023 Plans (Stock Awards). The Stock Awards vest either based solely on the satisfaction of time-based service conditions or on the satisfaction of time-based service conditions combined with performance criteria. Stock Awards are subject to forfeiture if the holder’s services to the Company terminate before vesting. Stock Awards granted with only time-based service vesting conditions generally vest over three-year and four-year service periods, as defined in the terms of each award. Stock Awards that vest based on the satisfaction of time-based service conditions combined with performance criteria generally vest over a three-year service and performance period, based on performance criteria established at the time of the award. The portion of the Stock Award that is earned may equal or be more or less than the targeted number of shares subject to the Stock Award depending on whether the performance criteria are met. F- 31 Stock Awards activity for the years ended December 31, 2023, 2022 and 2021 is summarized below: Weighted- average grant Performance date fair and value Restricted stock units Time-based time-based Total per share Unvested restricted stock units as of December 31, 2020 (1) 245,462 88,458 333,920 $ 49.29 Granted 240,044 88,902 328,946 56.01 Vested ( 109,504 ) — ( 109,504 ) 52.79 Forfeited/canceled ( 86,836 ) ( 78,248 ) ( 165,084 ) 46.88 Unvested restricted stock units as of December 31, 2021 (1) 289,166 99,112 388,278 $ 54.81 Unvested and expected to vest restricted stock units outstanding as of December 31, 2021 331,358 $ 54.98 Unvested restricted stock units as of December 31, 2021 289,166 99,112 388,278 $ 54.81 Granted 769,976 164,722 934,698 29.76 Vested ( 142,942 ) ( 37,678 ) ( 180,620 ) 55.04 Forfeited/canceled ( 95,259 ) ( 42,959 ) ( 138,218 ) 45.10 Unvested restricted stock units as of December 31, 2022 (1) 820,941 183,197 1,004,138 $ 32.72 Unvested and expected to vest restricted stock units outstanding as of December 31, 2022 840,413 $ 32.37 Unvested restricted stock units as of December 31, 2022 820,941 183,197 1,004,138 $ 32.72 Granted 1,214,144 621,990 1,836,134 12.29 Vested ( 214,644 ) ( 15,618 ) ( 230,262 ) 35.68 Forfeited/canceled ( 674,037 ) ( 442,881 ) ( 1,116,918 ) 23.62 Unvested restricted stock units as of December 31, 2023 (1) 1,146,404 346,688 1,493,092 $ 14.67 Unvested and expected to vest restricted stock units outstanding as of December 31, 2023 1,159,877 $ 14.79 Weighted- average grant Performance date fair and value Restricted stock awards Time-based time-based Total per share Unvested restricted stock awards outstanding as of December 31, 2020 (1) 42,076 33,355 75,431 $ 93.96 Vested ( 15,728 ) — ( 15,728 ) 91.17 Forfeited/canceled ( 15,932 ) ( 27,726 ) ( 43,658 ) 98.05 Unvested restricted stock awards outstanding as of December 31, 2021 (1) 10,416 5,629 16,045 $ 87.12 Unvested and expected to vest restricted stock awards outstanding as of December 31, 2021 15,532 $ 90.08 Unvested restricted stock awards outstanding as of December 31, 2021 10,416 5,629 16,045 $ 87.12 Vested ( 4,496 ) ( 5,629 ) ( 10,125 ) 99.46 Forfeited/canceled ( 5,134 ) — ( 5,134 ) 74.25 Unvested restricted stock awards outstanding as of December 31, 2022 (1) 786 — 786 $ 59.55 Unvested and expected to vest restricted stock awards outstanding as of December 31, 2022 748 $ 60.39 Unvested restricted stock awards outstanding as of December 31, 2022 786 — 786 $ 59.55 Vested ( 786 ) — ( 786 ) 59.55 Unvested restricted stock awards outstanding as of December 31, 2023 — — — $ — Unvested and expected to vest restricted stock awards outstanding as of December 31, 2023 — $ — (1) Outstanding restricted stock units and restricted stock awards are based on the maximum payout of the targeted number of shares. As of December 31, 2023 , the unrecognized compensation cost related to unvested employee restricted stock units was $ 11,771 , excluding estimated forfeitures. This amount is expected to be recognized over a weighted-average period of 1.9 years. F- 32 Employee stock purchase plan The Company’s 2014 Employee Stock Purchase Plan (ESPP) provides for the grant to all eligible employees an option to purchase stock under the ESPP, within the meaning Section 423 of the Internal Revenue Code. The ESPP permits participants to purchase common stock through payroll deductions of up to 15 % of their eligible compensation, which includes a participant’s base straight time gross earnings, incentive compensation, bonuses, overtime and shift premium, but exclusive of payments for equity compensation and other similar compensation. A participant may purchase a maximum of 1,500 shares during a purchase period. Amounts deducted and accumulated by the participant are used to purchase shares of the Company’s common stock at the end of each six-month period. The purchase price of the shares will be 85 % of the lower of the fair market value of the Company’s common stock on the first trading day of each offering period or on the exercise date. The offering periods are currently approximately six months in length beginning on the first business day on or after March 1 and September 1 of each year and ending on the first business day on or after September 1 and March 1 approximately six months later. As of December 31, 2023 , a total of 550,595 shares of common stock were available for sale pursuant to the ESPP. The number of shares available for sale under the ESPP is increased annually on the first day of each fiscal year equal to the least of: • 179,069 shares; • 1.5 % of the outstanding shares of the Company’s common stock on the last day of the Company’s immediately preceding fiscal year; or • such other amount as may be determined by the administrator. For 2023 , an additional 179,069 shares were added to the ESPP share reserve pursuant to the provision described above. Stock-based compensation Stock-based compensation expense recognized for the years ended December 31, 2023, 2022 and 2021, was as follows: Years ended December 31, Stock-based compensation expense by type of award: 2023 2022 2021 Restricted stock units and restricted stock awards $ 7,037 $ 11,748 $ 10,229 Employee stock purchase plan 390 535 714 Total stock-based compensation expense $ 7,427 $ 12,283 $ 10,943 Employee stock-based compensation expense was calculated based on awards of stock options, restricted stock units and restricted stock awards ultimately expected to vest based on the Company’s historical award cancellations. The employee stock-based compensation expense recognized for the years ended December 31, 2023, 2022 and 2021 has been reduced for estimate forfeitures of restricted stock at a rate of 5.3 %, 4.1 % and 4.1 %, respectively. ASC 718 – Compensation-Stock Compensation requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. For the years ended December 31, 2023, 2022 and 2021, respectively, stock-based compensation expense recognized under ASC 718, included in cost of revenue, research and development expense, sales and marketing expense, and general and administrative expense was as follows: Years ended December 31, 2023 2022 2021 Cost of revenue $ 540 $ 1,127 $ 1,106 Research and development 1,592 1,591 1,276 Sales and marketing 1,598 2,785 2,388 General and administrative 3,697 6,780 6,173 Total stock-based compensation expense $ 7,427 $ 12,283 $ 10,943 F- 33 Valuation assumptions The employee stock-based compensation expense is recognized under ASC 718. Stock-based compensation cost for stock awards is based on the number of shares ultimately expected to vest, estimated at each reporting date based on management’s expectations regarding the relevant performance criteria. The value of the award that is ultimately expected to vest is recognized as expense on a straight-line basis over the employee’s requisite service period for stock awards with a time-based service condition and on a graded vesting basis over the employee’s requisite service period for stock awards with performance and time-based service conditions. Stock-based compensation cost for the employee stock purchase plan is determined at the grant date using the Black-Scholes option pricing model. During the years ended December 31, 2023, 2022 and 2021, the Company did not grant any stock option awards. The following table displays the assumptions that have been applied to estimate the fair value of the Company’s shares to be issued under the ESPP using the Black-Scholes option pricing model. 2023 2022 2021 Expected term (years) 0.50 0.50 0.50 Risk free interest rate 3.51 - 5.36 % 0.07 - 3.51 % 0.07 - 0.12 % Expected dividend yield None None None Volatility 47.97 - 71.53 % 47.97 - 59.21 % 44.59 - 83.92 % 9. Commitments and contingencies Purchase obligations The Company had approximately $ 83,000 of outstanding purchase orders due within one year with its outside vendors and suppliers as of December 31, 2023 . The Company has $ 2,057 accrued within accounts payable and other accrued expenses in the consolidated balance sheet as of December 31, 2023 related to estimated losses for firm commitment contractual obligations under these agreements. Losses on these firm commitment contractual obligations are recognized based upon the terms of the respective agreement and similar factors considered for the write-down of inventory, including expected sales requirements as determined by internal sales forecasts. Warranty obligation The following table identifies the changes in the Company’s aggregate product warranty liabilities for the years ended December 31, 2023, 2022 and 2021, respectively: December 31, 2023 2022 2021 Product warranty liability at beginning of period $ 19,913 $ 13,726 $ 14,394 Accruals for warranties issued 9,843 10,416 9,168 Adjustments related to preexisting warranties (including changes in estimates) 5,014 8,234 ( 597 ) Settlements made (in cash or in kind) ( 11,292 ) ( 12,463 ) ( 9,239 ) Product warranty liability at end of period $ 23,478 $ 19,913 $ 13,726 During the year ended December 31, 2023, the Company recorded $ 5,014 of changes in estimates related to preexisting warranties due to data and information that became available during the current year. The changes in estimates were primarily due to the increased cost to repair for all products stemming from the current year inflationary environment and increased product failure rates. Legislation and HIPAA The healthcare industry is subject to numerous laws and regulations of federal, state and local governments. These laws and regulations include, but are not necessarily limited to, matters such as licensure, accreditation, government healthcare program participation requirements, reimbursement for patient services, and Medicare and Medicaid fraud and abuse. Compliance with government laws and regulations can be subject to future government review and interpretation as well as regulatory actions unknown or unasserted at this time. The Health Insurance Portability and Accountability Act of 1996 (HIPAA) was enacted to ensure health insurance portability, reduce healthcare fraud and abuse, guarantee security and privacy of health information, and enforce standards for health information. The Health Information Technology for Economic and Clinical Health Act (HITECH Act), in part, imposes notification requirements of certain security breaches relating to protected health information. The Company is not aware of any pending claims against it under the HIPAA and HITECH regulations that are applicable to the Company’s business. F- 34 Legal proceedings The Company is party to various legal proceedings and investigations arising in the normal course of business. The Company carries insurance, subject to specified deductibles under the policies, to protect against losses from certain types of legal claims. At this time, the Company does not anticipate that any of these other proceedings arising in the normal course of business will have a material adverse effect on the Company’s business. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources, and other factors. 10. Restructuring charges The Company incurred $ 3,426 of restructuring costs during the year ended December 31, 2023, primarily in connection with the Company's cost reduction initiatives, which were recorded within general and administrative expense in the consolidated statements of comprehensive loss. The restructuring charges consisted primarily of severance and termination benefits. Other related costs consisted of targeted workforce reductions, office downsizing, centralizing manufacturing activities, and equipment relocation. The Company had $ 638 of accrued liabilities related to restructuring charges as of December 31, 2023. 11 . Foreign currency exchange contracts and hedging As of December 31, 2023 and December 31, 2022 , the Company’s total non-designated and designated derivative contracts had notional amounts totaling approximately $ 30,373 and $ 0 , respectively, and $ 37,314 and $ 0 , respectively. These contracts were comprised of offsetting contracts with the same counterparty, each expires within one month . During the years ended December 31, 2023, 2022, and 2021 , these contracts had, net of tax, an unrealized gain or loss of $ 0 , an unrealized loss of $ 1,140 and an unrealized gain of $ 1,793 , respectively. The nonperformance risk of the Company and the counterparty did not have a material impact on the fair value of the derivatives. During the year ended December 31, 2023 , there were no ineffective portions relating to these hedges and the hedges remained effective through their respective settlement dates. During the year ended December 31, 2022 , there were three ineffective portions related to these hedges. During the year ended December 31, 2021, there were no ineffective portions relating to these hedges and the hedges remained effective through their respective settlement dates. As of December 31, 2023 , the Company had no designated hedges and five non-designated hedges. As of December 31, 2022 , the Company had no designated hedges and three non-designated hedges. Schedule II: Valuation and Quali fying Accounts Balance at Beginning Balance at of Year Additions Deletions End of Year Year ended December 31, 2023 Allowance for doubtful accounts (1) $ 77 $ 2,273 $ 9 $ 2,341 Allowance for sales returns (2) 483 8,457 8,461 479 Allowance for rental asset loss (3) 2,255 3,290 2,939 2,606 Year ended December 31, 2022 Allowance for doubtful accounts (1) $ 52 $ 97 $ 72 $ 77 Allowance for sales returns (2) 810 12,927 13,254 483 Allowance for rental asset loss (3) 1,290 2,940 1,975 2,255 Year ended December 31, 2021 Allowance for doubtful accounts (1) $ 52 $ 60 $ 60 $ 52 Allowance for sales returns (2) 742 11,034 10,966 810 Allowance for rental asset loss (3) 575 1,153 438 1,290 (1) The additions to the allowance for doubtful accounts represent the estimates of bad debt expense based upon factors for which the company evaluates the collectability of accounts receivable, with actual recoveries netted into additions. Deductions are the actual write-offs of the receivables. (2) The additions to the allowance for sales returns represent estimates of returns based upon historical returns experience, primarily for the direct-to-consumer sales channel. Deductions are the actual returns of products. (3) The additions to the allowance for rental asset loss represent estimated losses of the Company’s rental assets that will potentially be unrecoverable from the patient. Deductions are the actual write-offs of the rental assets. F- 35 EXHIBIT INDEX Exhibit Number Description Incorporated by Reference From Form Incorporated by Reference From Exhibit Number Date Filed 2.1 Agreement and Plan of Merger dated August 6, 2019, by and among Inogen, Inc., Move Merger Sub, Inc., New Aera, Inc. and Gregory J. Kapust, as the entitled holders’ agent. 8-K 2.1 08/07/19 2.2 Share Purchase Agreement dated July 10, 2023, by and among Inogen, Inc. and Mr. Adrien Mithalal, Mr. Jean-Sébastien Lantz, Mrs. Anne Reiser, CAAP Creation, Societe De Capital Risque Provencale Et Corse, Region Sud Investissement, Mérieux Participations 2, Relyens Innovation Santé and certain individual sellers identified herein . 8-K 2.1 07/13/23 3.1 Thirteenth Amended and Restated Certificate of Incorporation of the Registrant. 10-K 3.1 02/25/20 3.2 Amended and Restated Bylaws of the Registrant. 8-K 3.1 11/02/22 4.1 Specimen Common Stock Certificate of the Registrant. S-1/A 4.1 01/16/14 4.2 Description of Securities. 10-K 4.4 02/25/20 10.1+ Form of Director and Executive Officer Indemnification Agreement. S-1 10.1 11/27/13 10.2+ 2002 Stock Plan, as amended. S-1 10.2 11/27/13 10.3+ Form of Notice of Stock Option Grant and Stock Option Agreement under the 2002 Stock Plan, as amended. S-1 10.3 11/27/13 10.4+ 2012 Equity Incentive Plan, as amended. S-1 10.4 11/27/13 10.5+ Form of Stock Option Agreement under the 2012 Equity Incentive Plan. S-1 10.5 11/27/13 10.6+ 2014 Equity Incentive Plan. S-1/A 10.6 01/28/14 10.7A+ Form of Stock Option Agreement under the 2014 Equity Incentive Plan. 10-Q 10.1 11/07/17 10.7B+ Form of Restricted Stock Unit Agreement – Time-Based under the 2014 Equity Incentive Plan. 10-Q 10.2 11/07/17 10.7C+ Form of Restricted Stock Unit Agreement – Performance-Based under the 2014 Equity Incentive Plan. 10-Q 10.3 11/07/17 10.7D+ Form of Restricted Stock Award Agreement – Time-Based under the 2014 Equity Incentive Plan. 10-Q 10.4 11/07/17 10.7E+ Form of Restricted Stock Award Agreement – Performance-Based under the 2014 Equity Incentive Plan. 10-Q 10.5 11/07/17 10.8+ 2014 Employee Stock Purchase Plan. S-1/A 10.8 01/28/14 10.9+ Executive Incentive Compensation Plan. S-1 10.9 11/27/13 10.10 License Agreement, dated July 23, 2007, between the Registrant and Air Products and Chemicals, Inc. S-1/A 10.19 12/23/13 10.11 Amendment to License Agreement, dated October 23, 2009, between the Registrant and Air Products and Chemicals, Inc. S-1 10.20 11/27/13 10.12 Amendment No. 2 to License Agreement, dated October 4, 2010, between the Registrant and Air Products and Chemicals, Inc. S-1 10.21 11/27/13 90 Exhibit Number Description Incorporated by Reference From Form Incorporated by Reference From Exhibit Number Date Filed 10.13 Amendment No. 3 to License Agreement, dated March 22, 2011, between the Registrant and Air Products and Chemicals, Inc. S-1 10.22 11/27/13 10.14+ Amended and Restated Employment and Severance Agreement, effective January 1, 2017, between the Registrant and Byron Myers. 10-K 10.28 02/28/17 10.15 Lease Agreement by and between the Company, Cleveland American, LLC and Holdings Cleveland American, LLC, dated as of May 31, 2017. 10-Q 10.1 08/07/18 10.16 First Amendment to Lease Agreement between the Company, Cleveland American, LLC and Holdings Cleveland American, LLC, dated as of January 10, 2018. 10-Q 10.2 08/07/18 10.17 Second Amendment to Lease Agreement between the Company, Cleveland American, LLC and Holdings Cleveland American, LLC, dated as of May 1, 2018. 10-Q 10.3 08/07/18 10.18 Lease Agreement, dated June 19, 2019, by and between the Company, and RAF Pacifica Group – Real Estate Fund IV, LLC, APG Hollywood Center, LLC, and APG Airport Freeway Center, LLC. 10-Q 10.1 08/07/19 10.19 Lease Agreement, dated August 29, 2019, by and between the Company, and TCG Industrial Shiloh LLC. 10-Q 10.1 11/05/19 10.20 Lease Agreement Amendment No. 1, dated November 1, 2019, by and between the Company, and TCG Industrial Shiloh LLC. 10-Q 10.2 11/05/19 10.21+ Employment and Severance Agreement between the Company and Nabil Shabshab, dated January 22, 2021. 8-K 10.1 01/25/21 10.22 First Amendment to Agreement and Plan of Merger, dated August 6, 2019 between the Company and New Aera, dated January 18, 2021. 10-K 10.40 02/24/21 10.23+ Employment and Severance Agreement between the Company and George Parr, dated April 12, 2021. 10-Q 10.6 05/04/21 10.24+ Employment and Severance Agreement, between the Company and Stanislav Glezer, dated June 21, 2021. 10-Q 10.1 08/04/21 10.25+ Employment and Severance Agreement, between the Company and Jason M. Somer, dated July 12, 2021. 10-Q 10.2 08/04/21 10.26 First Amendment to Lease dated as of June 17, 2021, by and between the Company and RAF Pacifica Group – Real Estate Fund IV, LLC, APG Hollywood Center, LLC and APG Airport Freeway Center, LLC. 10-Q 10.1 11/04/21 10.27* Private Label Distribution Agreement, by and between the Company and OxyGo HQ Florida, LLC, dated as of September 23, 2021. 10-Q 10.2 11/04/21 10.28+ Transition Agreement and Release, dated September 30, 2021, between the Company and Brenton Taylor. 10-Q 10.3 11/04/21 10.29+ Amended and Restated Employment and Severance Agreement, dated October 11, 2021, between the Company and Stanislav Glezer. 10-Q 10.4 11/04/21 10.30+ Offer Letter by and between the Company and Michael K. Sergesketter, dated December 10, 2021. 8-K 10.1 12/13/21 91 Exhibit Number Description Incorporated by Reference From Form Incorporated by Reference From Exhibit Number Date Filed 10.31+ Transition Agreement and Release between the Company and Alison Bauerlein, dated December 10, 2021. 8-K 10.2 12/13/21 10.32+ Consulting Agreement by and between the Company and Raymond Huggenberger, effective December 29, 2021. 8-K 10.1 12/30/21 10.33+ Employment and Severance Agreement by and between the Company and Kristin A. Caltrider, effective March 21, 2022. 8-K 10.1 03/04/22 10.34+ Transition Agreement and Release between the Company and Bart Sanford, dated February 6, 2023. 8-K 10.1 02/10/23 10.35+ 2023 Equity Incentive Plan . 8-K 10.1 06/06/23 10.36A+ Form of Stock Option Agreement under the 2023 Equity Incentive Plan. 8-K 10.2 06/06/23 10.36B+ Form of Restricted Stock Unit Agreement (Time-Based) under the 2023 Equity Incentive Plan. 8-K 10.3 06/06/23 10.36C+ Form of Restricted Stock Unit Agreement (Performance-Based) under the 2023 Equity Incentive Plan . 8-K 10.4 06/06/23 10.37 Terms and Conditions of Convertible Bonds Issued by Physio-Assist dated July 10, 2023 . 8-K 10.1 07/13/23 10.38 Assignment and Assumption of Lease Agreement dated July 13, 2023 between Inogen, Inc. and Sonos, Inc. 8-K 10.1 07/18/23 10.39+ Severance Agreement and Release between the Company and George Parr, dated July 31, 2023. 8-K 10.1 08/11/23 10.40+ Offer Letter by and between Inogen, Inc. and Michael K. Sergesketter, dated September 6, 2023. 8-K 10.1 09/07/23 10.41+ Employment and Severance Agreement by and between the Company and Kevin Smith, dated November 10, 2023. 8-K 10.1 11/13/23 10.42+ Separation Agreement and Release by and between the Company and Nabil Shabshab, dated November 22, 2023. 8-K 10.1 11/27/23 10.43+ Employment and Severance Agreement by and between the Company and Michael Bourque, dated effective as March 4, 2024 . 8-K 10.1 01/24/24 10.44+ Employment Contract by and between the Company and Grégoire Ramade, dated October 5, 2023 Filed Herewith 10.45+ Addendum No. 1 to the Employment Contract dated January 4, 2024, between the Company and Gregoire Ramade. Filed Herewith 23.1 Consent of Deloitte & Touche LLP, Independent Registered Public Accounting Firm. Filed Herewith 24.1 Powers of Attorney (contained in the signature page to this Annual Report on Form 10-K). Filed Herewith 31.1 Certification of Principal Executive Officer pursuant to Exchange Act Rules 13a-14(a) and 15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. Filed Herewith 31.2 Certification of Principal Financial Officer pursuant to Exchange Act Rules 13a-14(a) and 15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. Filed Herewith 92 Exhibit Number Description Incorporated by Reference From Form Incorporated by Reference From Exhibit Number Date Filed 32.1~ Certifications of Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. Filed Herewith 97.1 Inogen, Inc. Clawback Policy Filed Herewith 101.INS Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document. 101.SCH Inline XBRL Taxonomy Extension Schema with Embedded Linkbase Documents. 104 The cover page of this Annual Report on Form 10-K, formatted in inline XBRL. + Indicates a management contract or compensatory plan. * Portions of the exhibit have been omitted pursuant to Item 601(b)(10) of Regulation S-K. The Company agrees to furnish to the Securities and Exchange Commission a copy of any omitted portions of the exhibit upon request. ~ The certifications attached as Exhibit 32.1 that accompany this Annual Report on Form 10-K, are deemed furnished and not filed with the Securities and Exchange Commission and are not to be incorporated by reference into any filing of Inogen, Inc. under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, whether made before or after the date of this Annual Report on Form 10-K, irrespective of any general incorporation language contained in such filing. 93 SIGNAT URES Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. INOGEN, INC. (Registrant) Dated: March 1, 2024 By: /s/ Kevin R. M. Smith Kevin R. M. Smith Chief Executive Officer President Director (Principal Executive Officer) POW ER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Kevin R. M. Smith and Michael K. Sergesketter, and each of them, as his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments to this Annual Report on Form 10-K, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his or her substitutes, may lawfully do or cause to be done by virtue thereof. Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated. Signature Title Date /s/ Kevin R. M. Smith Chief Executive Officer, President and Director March 1, 2024 Kevin R. M. Smith (Principal Executive Officer) /s/ Michael K. Sergesketter Chief Financial Officer March 1, 2024 Michael K. Sergesketter (Principal Accounting and Financial Officer) /s/ Elizabeth Mora Chairperson of the Board March 1, 2024 Elizabeth Mora /s/ Glenn Boehnlein Director March 1, 2024 Glenn Boehnlein /s/ Kevin King Director March 1, 2024 Kevin King /s/ Mary Katherine Ladone Director March 1, 2024 Mary Katherine Ladone /s/ Heather Rider Director March 1, 2024 Heather Rider /s/ Thomas West Director March 1, 2024 Thomas West 94