Sources: CMS, SSA, Medicare.gov, and BLS
Last updated · Sources: CMS, SSA, BLS
Official premium and IRMAA amounts
- CMS — 2026 Medicare Parts A & B Premiums and Deductibles; 2026 Part D IRMAA (Nov 14, 2025)
- Medicare.gov — Medicare costs
Rules, determinations and appeals
- SSA — Lower your IRMAA
- SSA — Form SSA-44 (Life-Changing Event)
- 20 CFR Part 418, Subpart B — Medicare Part B income-related monthly adjustment (MAGI definition §418.1010; tax year used §418.1135)
Law and inflation data used for projections
- 42 U.S.C. §1395r(i) — income-related reduction in premium subsidy, inflation adjustment (i)(5)
- BLS — CPI-U, U.S. city average, all items, not seasonally adjusted (CUUR0000SA0). October 2025 was not published due to the 2025 lapse in appropriations.