Lantheus Holdings, Inc. New Standards Disclosure

Recent Accounting Pronouncements

The Company has considered all new accounting standards issued by the Financial Accounting Standards Board (“FASB”).

Accounting Pronouncements Adopted During the Period

In December 2023, the FASB issued Accounting Standards Update (“ASU”) 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures,” which requires enhanced income tax disclosures, including specific categories and disaggregation of information in the effective tax rate reconciliation, disaggregated information related to income taxes paid, income or loss from continuing operations before income tax expense or benefit, and income tax expense or benefit from continuing operations. The requirements of the ASU are effective for annual periods beginning after December 15, 2024, with early adoption permitted. The Company adopted ASU 2023-09 prospectively and the disclosures included in this Annual Report on Form 10-K (“Form 10-K”) reflect the disclosures required under ASU 2023-09. See Note 5, “Income Taxes,” to these consolidated financial statements for more information.

Accounting Pronouncements Not Yet Adopted

In December 2025, the FASB issued ASU 2025-11, “Interim Reporting (Topic 270) Narrow-Scope Improvements,” which clarifies that the interim reporting requirements in Topic 270 apply to all entities that issue interim financial statements prepared in accordance with U.S. GAAP and consolidates such requirements within Topic 270. The amendments provide a comprehensive

list within Topic 270 of required interim disclosures, establishes a principle requiring disclosure of events or changes occurring after the end of the most recent annual reporting period that have a material impact on interim results and clarifies the form and content requirements applicable to interim financial statements. The requirements of ASU 2025-11 are effective for interim reporting periods within annual reporting periods beginning after December 15, 2027 (for the Company’s Form 10-Q for the three months ending March 31, 2028). The Company is currently in the process of evaluating the effects of this pronouncement on its consolidated financial statements and related disclosures.

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,” which simplifies the capitalization guidance by removing all references to software development project stages so that the guidance is neutral to different software development methods. Entities will now capitalize costs associated with internal-use software only when management has authorized and committed funding, and it is probable that the project will be completed and the software will be used to perform its intended function. ASU 2025-06 is effective for interim and annual periods beginning after December 15, 2027, with early adoption permitted. The Company is currently in the process of evaluating the effects of this pronouncement on its consolidated financial statements and related disclosures.

In July 2025, the FASB issued ASU 2025-05, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets,” which provides a practical expedient related to the estimation of expected credit losses for accounts receivable and current contract assets that arise from transactions accounted for under ASC 606, “Revenue Recognition.” ASU 2025-05 requires an entity to disclose whether it has elected to use the practical expedient. An entity that makes the accounting policy election is required to disclose the date through which subsequent cash collections are evaluated. The requirements of ASU 2025-05 are effective for annual periods beginning after December 15, 2025, and interim periods beginning in the first quarter of 2026. Early adoption is permitted in both interim and annual reporting periods in which financial statements have not yet been issued or made available for issuance. The Company is currently in the process of evaluating the effects of this pronouncement and believes that the adoption will not have a material impact on its consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU 2024-04, “Debt - Debt with Conversion and Other Options (Subtopic 470-20),” which clarifies the requirements for determining whether certain settlements of convertible debt instruments should be accounted for as an induced conversion rather than as extinguishment of debt. The requirements of ASU 2024-04 are effective for the annual periods beginning after December 15, 2025, including interim periods within those fiscal years. Early adoption is permitted. For the Company, the requirements under ASU 2024-04 will be effective for its Form 10-Q for the first quarter of 2026. The adoption of ASU 2024-04 is not expected to have a material impact on the Company’s consolidated financial statements and related disclosures in 2026.

In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40),” and in January 2025, the FASB issued ASU 2025-01, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date.” ASU 2024-03 requires additional income statement disclosures, including the disaggregation of specific categories of expenses underlying the line items presented on the income statement. Additionally, ASU 2024-03 requires enhanced disclosure of selling expenses. As clarified by ASU 2025-01, the requirements of the guidance are effective for annual periods beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027. For the Company, annual reporting requirements under ASU 2024-03 will be effective for its Form 10-K for the year ending December 31, 2027 and interim reporting requirements will be effective beginning in the first quarter of 2028. Early adoption is permitted and the amendments should be applied on a prospective basis, however retrospective application is permitted. The Company is currently in the process of evaluating the impact of this pronouncement on its consolidated financial statements and related disclosures.