Onterris, Inc. New Standards Disclosure

Recently Adopted Accounting Pronouncements

ASU 2023-05 —In August 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-05 Business Combinations — Joint Venture Formations (Subtopic 805-60): Recognition and Initial Measurement, under which an entity that qualifies as either a joint venture or a corporate joint venture is required to apply a new basis of accounting upon the formation of the joint venture. Specifically, the ASU provides that a joint venture or a corporate joint venture must initially measure its assets and liabilities at fair value on the formation date. The amendments in ASU 2023-05 are effective for all joint ventures within the ASU’s scope that are formed on or after January 1, 2025. The Company adopted the standard on January 1, 2025. The adoption of the standard did not have a material impact on the Company's consolidated financial statements.

ASU 2023-09 —In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which improves the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. ASU 2023-09 is effective for the Company's fiscal year beginning after December 15, 2024 and is being applied using the retrospective approach. The Company adopted the standard on January 1, 2025. The adoption did not have an impact on the recognition or measurement of income taxes in the Company's consolidated financial statements, and only required additional disclosures. The Company updated its income tax disclosures in accordance with the guidance.

Recently Issued Accounting Pronouncements Not Yet Adopted

ASU 2024-03 —In November 2024, the FASB issued ASU 2024-03, Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (ASU 2024-03), which is intended to improve the disclosures about a public business entity’s expenses and address requests from investors for more detailed information about the types of expenses

in commonly presented expense captions (such as cost of sales; selling, general, and administrative expenses; and research and development). ASU 2024-03 is effective for the Company's fiscal year beginning January 1, 2027 and interim periods within fiscal years beginning after December 15, 2027, and allows the use of a prospective or retrospective approach. The Company plans to adopt the standard on January 1, 2027 and is currently evaluating the impact of the adoption of the standard on its consolidated financial statements.

ASU 2025-06 —In September 2025, the FASB issued ASU 2025-06, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software (ASU 2025-06), which removes all references to software development project stages, making the guidance neutral to different software development methodologies. Under the ASU, software capitalization will begin when management has authorized and committed to funding the software project and it is probable that the project will be completed and the software will be used as intended. ASU 2025-06 is effective for the Company's fiscal year beginning January 1, 2028, and interim periods within fiscal years beginning after December 15, 2027, and allows the use of a prospective, modified transition, or retrospective approach. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of the standard on its consolidated financial statements.