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Medicare Open Enrollment 2026: Dates, Rules and What to Review

By Brian Monahan Updated October 4, 2026

Reviewed October 4, 2026. Medicare Open Enrollment for 2027 coverage runs from October 15 through December 7, 2026. During this window you can join, switch or drop a Medicare Advantage plan or a Part D drug plan, or move between Original Medicare and Medicare Advantage. Any change you make takes effect on January 1, 2027, as long as the plan receives your request by December 7 (Medicare.gov).

Quick answer: Read your plan’s Annual Notice of Change, check that your drugs, doctors and pharmacies are still covered for 2027, compare plans in Medicare Plan Finder, and make any switch by December 7. If you’re happy with your plan and it isn’t ending, you don’t have to do anything: it renews automatically.

Medicare Open Enrollment 2026 key dates

Date	What happens
By September 30, 2026	Your Medicare Advantage or Part D plan mails its Annual Notice of Change (ANOC) for 2027
Early October 2026	2027 plans and prices appear in Medicare Plan Finder
October 15, 2026	Open Enrollment begins
December 7, 2026	Last day to make a change; the plan must receive your request by this date
January 1, 2027	New coverage starts
January 1 to March 31, 2027	Medicare Advantage Open Enrollment Period (one change for people already in a Medicare Advantage plan)

The October 15 to December 7, 2026 dates are confirmed by CMS. Open Enrollment is sometimes called the Annual Enrollment Period, or AEP. For how it differs from the January to March window, see our guide to AEP vs. OEP.

What you can change during Open Enrollment

According to Medicare.gov, during Open Enrollment you can:

Switch from Original Medicare to a Medicare Advantage plan
Switch from a Medicare Advantage plan back to Original Medicare
Join, drop or switch Medicare Advantage plans, with or without drug coverage
Join, drop or switch a Medicare drug plan (Part D) if you have Original Medicare

If you make more than one change during the period, the last request the plan receives before December 7 is the one that counts.

What Open Enrollment does not cover

Open Enrollment is not the time to sign up for Part A or Part B for the first time. If you missed your Initial Enrollment Period, you generally use the General Enrollment Period (January 1 to March 31) or a Special Enrollment Period. It also doesn’t give you a federal right to buy a Medicare Supplement (Medigap) policy without health questions. If you’re leaving Medicare Advantage for Original Medicare, read how to switch from Medicare Advantage to Medigap before you act.

What’s changing for 2027

CMS released its 2027 plan landscape on September 28, 2026. Highlights for people comparing plans this fall:

Medicare Advantage premiums: the weighted average monthly Medicare Advantage premium is projected to fall from $14.37 in 2026 to $12.00 in 2027.
Stand-alone Part D premiums: the average total monthly premium is projected at $36 in 2027, up from $35.09 in 2026.
Plan choice: CMS says more than 99% of people with Medicare have access to at least one Medicare Advantage plan, and 97% have 10 or more choices.
Drug costs: in 2027 the standard Part D deductible is $700 and out-of-pocket drug costs are capped at $2,400, up from $615 and $2,100 in 2026 (Medicare.gov).
Negotiated drug prices: Medicare’s negotiated prices for 15 more drugs, including Ozempic, Wegovy and Trelegy Ellipta, take effect January 1, 2027.

Averages hide big differences between plans and counties, so check your own plan’s ANOC. Our full rundown of Medicare changes for 2027 covers the details.

How to review your coverage, step by step

Read your Annual Notice of Change. It lists changes to premiums, deductibles, copays, the drug list (formulary), pharmacy network and provider network for 2027.
List your drugs, doses and pharmacies. Enter them in Medicare Plan Finder to see estimated 2027 costs for each plan. Watch for drugs that moved to a higher drug tier.
Check your doctors and hospitals. Call your providers and confirm they’ll be in network for 2027. This matters most in HMOs. See HMO vs. PPO.
Compare total yearly cost, not just the premium. Add premiums, deductibles, copays and the plan’s maximum out-of-pocket limit. Our plan comparison worksheet helps.
Look at extra benefits carefully. Dental, vision, hearing and OTC allowances vary. Check annual maximums and networks, for example in our Medicare Advantage dental guide.
Check star ratings. Plan Finder shows each plan’s overall star rating from 1 to 5.
Enroll by December 7. You can enroll through Plan Finder, by calling the plan, or by calling 1-800-MEDICARE (1-800-633-4227; TTY 1-877-486-2048).

For a printable version of these steps, use our annual Medicare plan review checklist.

If you miss the December 7 deadline

You may still have options after Open Enrollment ends:

Medicare Advantage Open Enrollment Period (January 1 to March 31): if you’re in a Medicare Advantage plan, you can switch to another Medicare Advantage plan, or drop it and return to Original Medicare and join a drug plan. You get one change.
5-star Special Enrollment Period: you can switch to a Medicare Advantage or drug plan with a 5-star overall rating once between December 8 and November 30.
Extra Help or Medicaid: Medicare.gov says people who get Extra Help may be able to change drug coverage once a month.
Other Special Enrollment Periods: moving, losing other coverage, or your plan leaving your area can open a window.

Who can help

Free, unbiased counseling is available from your State Health Insurance Assistance Program (SHIP) and from 1-800-MEDICARE. If someone else will help you make decisions, they may need an Appointment of Representative form. Be wary of anyone who calls you unexpectedly and asks for your Medicare number. Medicare’s marketing rules generally don’t allow plans to call you about enrolling unless you’ve asked them to contact you.

Frequently asked questions

When is Medicare Open Enrollment for 2027 coverage?

October 15 to December 7, 2026. Changes take effect January 1, 2027.

Do I have to do anything during Open Enrollment?

No. If your plan is continuing and still meets your needs, it renews automatically. Still, review your Annual Notice of Change, because premiums, drug lists and networks can change every year.

Can I switch from Medicare Advantage to Original Medicare during Open Enrollment?

Yes. You can also join a stand-alone Part D plan at the same time. Buying a Medigap policy is a separate step, and insurers in most states can use medical underwriting unless you have a guaranteed issue right.

Can I change Medigap plans during Open Enrollment?

Open Enrollment doesn’t apply to Medigap. You can apply to change Medigap policies at any time, but outside your Medigap Open Enrollment Period or a guaranteed issue right, the insurer may ask health questions.

What if I make a mistake or change my mind?

You can make another change before December 7. The last valid request the plan receives counts. If you’re in Medicare Advantage on January 1, you also get one change from January 1 to March 31.

Is the Part B premium changing for 2027?

CMS usually announces the next year’s Part B premium and deductible in the fall. As of this review, the 2027 amounts haven’t been announced. In 2026 the standard Part B premium is $202.90 a month. See our Part B premium guide.

This article is general information, not individual insurance advice. Medicare365 is not affiliated with or endorsed by the U.S. government or the federal Medicare program.