SECTION 2. CHANGE

TO PREMIUM GROWTH ADJUSTMENT METHODOLOGY

The Applicable Percentage Table and the Section 36B Required Contribution Percentage indexing adjustments are computed using the methodology described in section 4 of Rev. Proc. 2014-37, 2014-33 I.R.B. 363, and in guidance issued by the Department of Health and Human Services (HHS). For 2025 and a number of years prior to 2025, the rate of premium growth was based on per enrollee spend

ing for employer-sponsored insurance as published in the National Health Expenditure Account. However, beginning in calendar year 2026, HHS guidance provided a new premium growth measure that captures increases in individual market premiums in addition to increases in employer-sponsored insurance premiums for purposes of calculating the premium adjustment percentage for the 2026 benefit year and beyond. See HHS Marketplace Integrity and Affordability rule, 90 Fed. Reg. 27074 (June 25, 2025). For taxable year 2027, the Treasury Department and the IRS will use the premium growth measure provided in the 2026 HHS Marketplace Integrity and Affordability rule for purposes of the Applicable Percentage Table and the Section 36B Required Contribution Percentage indexing adjustments.