Medicare Open Enrollment 2026: Dates and 7-Step Checklist

The 2026 enrollment calendar

Medicare has one main window each fall when anyone with Medicare can change how they get their coverage. In 2026 it runs from Thursday, October 15 through Monday, December 7. There is a second, narrower window at the start of each year for people already in Medicare Advantage. Both are described on Medicare.gov.

Coverage changes made in the fall window start January 1, 2027. Changes made in the January–March window start the first of the month after the plan gets your request.

What you can and cannot change in the fall

During October 15 to December 7 you can:

• Move from Original Medicare to a Medicare Advantage plan
• Move from a Medicare Advantage plan back to Original Medicare
• Switch from one Medicare Advantage plan to another
• Join a Part D prescription drug plan for the first time
• Switch from one Part D plan to another
• Drop Part D coverage entirely

You cannot use this window to:

• Enroll in Part A or Part B for the first time (that is the Initial Enrollment Period around your 65th birthday, or the General Enrollment Period)
• Buy or change a Medigap supplement policy without health questions (Medigap has separate rules; see below)

If you make more than one change during the window, the last one submitted by December 7 is the one that counts.

The January–March window is narrower

The Medicare Advantage Open Enrollment Period, January 1 through March 31, exists as a safety valve. If you picked an Advantage plan in the fall and find in January that your doctor is not in the network or your drug is not covered, you can switch once. Medicare.gov lists what is allowed: “Switch to another Medicare Advantage Plan with or without drug coverage, or drop your Medicare Advantage Plan and return to Original Medicare.”

You cannot use it to move from Original Medicare into Medicare Advantage, and you cannot use it to switch from one standalone Part D plan to another if you are on Original Medicare.

The 2026 numbers you will see on plan documents

Plan comparisons only make sense against the base costs of Medicare itself. These are the 2026 figures from the CMS fact sheet:

You pay the Part B premium whether you choose Original Medicare or Medicare Advantage. Some Advantage plans advertise a “Part B giveback” that refunds part of it. Higher-income enrollees pay more; the full table is in the Part B premium and IRMAA article.

The 2027 amounts are not out yet. CMS released the 2026 figures on November 14, 2025 and the 2025 figures on November 8, 2024, so expect the 2027 premium during the second half of open enrollment. Our IRMAA brackets page updates the day CMS publishes.

What this means for you

Example 1: Retired teacher on Original Medicare with a Part D plan, happy with her doctors. She does not need to change anything, but her Part D plan’s Annual Notice of Change shows her blood pressure drug moved to a higher tier for 2027. During the October 15 to December 7 window she compares drug plans on Medicare.gov’s plan finder, enters her exact prescriptions, and switches to a plan that keeps the drug on a lower tier. Her Original Medicare coverage is untouched. Her new drug plan starts January 1, 2027 (Medicare.gov).

Example 2: Couple in a Medicare Advantage plan that is leaving their county. Their plan mails a non-renewal notice. If they do nothing, they will be moved to Original Medicare on January 1 with no drug coverage. In the fall window they pick a new Advantage plan with drug coverage. If it does not work out, they can switch again between January 1 and March 31, 2027.

Example 3: Man turning 65 in November 2026. His Initial Enrollment Period, not the fall open enrollment, governs his first Part A and Part B sign-up, and it overlaps with the open enrollment window. He enrolls in Part B, and because his premium will be deducted from Social Security, he budgets for $202.90 a month in 2026 and a different amount in 2027 once CMS announces it (CMS fact sheet). He also uses his one-time Medigap open enrollment, the limited window after Part B starts, when insurers cannot refuse him or charge more for health conditions.

The 7-step open enrollment checklist

Work through these between now and December 7.

Step 1: Read your Annual Notice of Change (before October 15)

Every Medicare Advantage and Part D plan mails this before open enrollment begins. It lists every 2027 change: premium, deductible, copays, drug formulary, pharmacy network, provider network, and extra benefits. Mark anything that gets worse for you.

Step 2: List your doctors, hospitals and prescriptions

Write down every prescriber, specialist and hospital you use, and every prescription with dose and quantity. This list is what you will check plans against. For Original Medicare with a standalone drug plan, only the prescription list matters for the plan comparison.

Step 3: Confirm your Social Security and Medicare accounts work

Create or log in to your account at Medicare.gov and your my Social Security account at ssa.gov. The Medicare account saves your drug list for plan comparisons. The Social Security account shows your Part B deduction and, in December, your COLA notice with the 2027 premium. The 2026 COLA raised the average retired-worker benefit from $2,015 to $2,071 (SSA fact sheet); the 2027 COLA is expected in October.

Step 4: Compare plans on Medicare.gov (once 2027 plans are posted)

Plan details for 2027 appear on the plan finder shortly before open enrollment opens. Enter your zip code, your drugs and your pharmacies. Sort by “lowest yearly drug and premium cost,” not by premium alone. A plan with a $0 premium and high copays often costs more over a year than a plan with a modest premium.

Step 5: Check the networks (Medicare Advantage only)

Call each doctor’s office and ask whether they accept the specific 2027 plan, not just “Medicare.” Networks change January 1. A plan directory is a starting point, but the office’s own answer is what counts.

Step 6: Decide by early December, not December 7

Submit changes online through Medicare.gov, by calling 1-800-MEDICARE, or through the plan directly. Do it at least a week early so a missing signature or a website outage does not cost you the year. Save the confirmation number.

Step 7: Verify in January

Your new card and welcome packet should arrive before January 1, 2027. Check that your first January claim processes under the new plan. If something is wrong with an Advantage plan, you have until March 31, 2027 to switch once.

Medigap: different rules, different clock

Medigap (Medicare Supplement) policies are not part of the fall open enrollment. Your no-health-questions window is a limited period starting the month you are 65 or older and enrolled in Part B. After that, in most states, an insurer can review your health before selling you a policy or can charge more. A few states have their own annual Medigap windows. If you are thinking of leaving Medicare Advantage for Original Medicare plus Medigap, check whether you can get a Medigap policy before you drop the Advantage plan.

Watch for scams during open enrollment

Open enrollment is the peak season for fraud calls. Medicare does not call you to sell plans, and it never asks for your Medicare number to “verify” coverage. Agents cannot legally cold-call you about Medicare Advantage or Part D unless you asked them to. If a caller pressures you to switch plans today, hang up and call 1-800-MEDICARE.

Key dates at a glance

Dates are from Medicare.gov. For how the Part B premium interacts with your January Social Security payment, see the 2027 payment schedule.

This article is for general information only and is not financial, tax, legal or insurance advice. Found an error? See our corrections policy.