Medicare Open Enrollment 2026: What to Review Before 7 December

Medicare’s Annual Enrollment Period is open right now — from 15 October to 7 December 2026 — and every choice you make takes effect on 1 January 2027. The 2027 numbers are in: Part B at $202.90 a month, the Part D out-of-pocket cap rising to $2,100, and a new Part B projection for 2027 that is the smallest increase in years. If you are 65+, or helping a parent who is, here is the review worth doing before 7 December.

The dates

Annual Enrollment Period (AEP): 15 October – 7 December 2026. Changes you make take effect 1 January 2027. Missing the window means waiting a year — with only narrow exceptions — so this is the one autumn deadline that really bites.

Budget these four numbers first

• Part B premium: $202.90 a month in 2026 (up from $185), deducted from most Social Security cheques; Part B deductible: $283. The 2027 trustee-projected premium is about $209.50 (≈+3.25%) — the smallest rise since 2023.
• Part D out-of-pocket cap: $2,100 for 2026 (up $100 from 2025), with a maximum Part D deductible of $615. Prices negotiated for some high-cost drugs begin to apply for the first time.
• IRMAA surcharges for higher earners: $81.20–$487 a month on top of Part B in 2026, based on income from two years back; the top IRMAA bracket ($500k single / $750k joint) is frozen through 2028.
• Drug-cost floors: insulin capped at $35 a month under Part D, and adult recommended vaccines at $0 cost-sharing — the two most predictable savings in the whole programme.

The trap: auto-renewing without reading the ANOC

Every September your plan sends an Annual Notice of Change (ANOC) — premiums, deductibles, drug tiers and pharmacy networks all change year to year. The number-one budget mistake is filing it unread and discovering in January that your drug moved to a higher tier. Read the ANOC, then compare plans on Medicare’s Plan Finder with your actual prescriptions entered.

The second trap: the Advantage-to-Medigap door

If you are in a Medicare Advantage plan and thinking of moving back to Original Medicare with a Medigap supplement, know this: outside the initial enrollment period, Medigap insurers in most states can use medical underwriting — they can charge more or decline you. The door back is not always open at the same price. Check your state’s rules before you switch.

New in 2026: IRMAA planning and Part D caps

Two changes matter for budgeting. First, the Part D cap of $2,100 is a genuine ceiling on drug spending — once you hit it, covered drugs cost nothing more that year, so spread-out timing of prescriptions matters less than it used to. Second, if you are still working or just retired, remember IRMAA looks back two years: a high-income year in 2025 can set your 2027 surcharge, and life-changing events (retirement, divorce, the death of a spouse) let you file for a reconsideration of the surcharge.

Free help before you decide

• Medicare.gov Plan Finder — compare plans with your own drugs and pharmacies.
• SHIP counselors (shiphelp.org) — free, state-level, one-to-one counselling, not sales.
• 1-800-MEDICARE — the official helpline, open 24 hours.

None of these is trying to sell you a plan, which is exactly why they belong before any broker conversation.

For readers in the UK and Canada

Medicare is US-only, but the “read the renewal notice” habit applies everywhere.