(Mark One)☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026OR ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF1934 For the Transition Period FromtoCommission file number: 001-36309 INOGEN, INC. (Exact name of registrant as specified in its charter) 33-0989359(I.R.S. EmployerIdentification No.) Delaware(State or other jurisdiction ofincorporation or organization)500 Cummings Center, Suite 2800Beverly, Massachusetts(Address of principal executive offices) Registrant’s telephone number, including area code: (805) 562-0500 Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of theSecurities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to filesuch reports), and (2) has been subject to such filing requirements for the past 90 days.Yes☒No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to besubmitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorterperiod that the registrant was required to submit such files).Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, asmaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,”“smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filer☐Non-accelerated filer☐Emerging growth company☐ Accelerated filer☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition periodfor complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).Yes☐No☒ As of May 1, 2026, the registrant had 27,074,516 shares of common stock, par value $0.001, outstanding. TABLE OF CONTENTS Part I – Financial Information Item 1.Financial Statements3Consolidated Balance Sheets (unaudited) as of March 31, 2026 and December 31, 20253Consolidated Statements of Comprehensive Loss (unaudited) for the Three Months Ended March 31, 2026 andMarch 31, 20254Consolidated Statements of Stockholders’ Equity (unaudited) for the Three Months Ended March 31, 2026 andMarch 31, 20255Consolidated Statements of Cash Flows (unaudited) for the Three Months Ended March 31, 2026 and March31, 20256Condensed Notes to the Consolidated Financial Statements (unaudited)8Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations20Item 3.Quantitative and Qualitative Disclosures about Market Risk29Item 4.Controls and Procedures30Part II – Other InformationItem 1.Legal Proceedings31Item 1A.Risk Factors31Item 2.Unregistered Sales of Equity Securities and Use of Proceeds31Item 3.Defaults Upon Senior Securities32Item 4.Mine Safety Disclosures32Item 5.Other Information32Item 6.Exhibits33SIGNATURES34 INOGEN, INC. PART I – FINANCIAL INFORMATION Inogen, Inc.Consolidated Balance Sheets(unaudited)(amounts in thousands, except share and per share amounts) March 31,2026December 31,2025 Inogen, Inc.Consolidated Statements of Comprehensive Loss(unaudited)(amounts in thousands, except share and per share amounts) Inogen, Inc.Consolidated Statements of Stockholders’ Equity(unaudited)(amounts in thousands, except share amounts) Inogen, Inc.Consolidated Statements of Cash Flows(unaudited)(amounts in thousands) Inogen, Inc.Consolidated Statements of Cash Flows (continued)(unaudited)(amounts in thousands) Inogen, Inc.Condensed Notes to the Consolidated Financial Statements(unaudited)(amounts in thousands, except share and per share amounts) 1. Business overview Inogen, Inc., or the Company, is a medical technology company focused on the development, manufacture, and commercializationof respiratory products, including portable and stationary oxygen concentrators, airway clearance devices, and continuous positiveairway pressure, or CPAP, masks for the treatment of chronic respiratory conditions. The Company's portfolio includes portableoxygen concentrator systems designed to optimize output, weight, sound levels, and battery life, as well as stationary oxygenconcentrators, the Simeox airway clearance system and Aurora CPAP masks. The Company operates both as a medical technologycompany and as a home medical equipment provider, with accreditation across all 50 U.S. states and a broad network of patients,prescribers, providers, and distribution partners. The Company generates the majority of its revenue from the sale and rental of portable oxygen concentrator systems and relatedaccessories t