Medicare Open Enrollment 2026 Checklist (Oct. 15

Key takeaways

Medicare open enrollment runs from October 15 to December 7, 2026, and changes take effect January 1, 2027.
Read your plan's Annual Notice of Change and compare total yearly costs, not just premiums.
Part D out-of-pocket drug costs are capped at $2,400 in 2027, up from $2,100 in 2026; also check your IRMAA and whether you qualify for Extra Help.

Run your own numbers Medicare Part D Calculator 2027 — Estimate your 2027 drug costs under the $2,400 out-of-pocket cap, and your payment plan bills.

Every fall, Medicare gives you a window to change how you get your coverage. Open enrollment runs from October 15 to December 7, 2026, and any change you make starts on January 1, 2027. If you do nothing, most plans renew automatically, but their premiums, drug lists and networks can change every year.

This checklist walks through what to review, in order, so you can decide whether to stay or switch.

Key dates

Date	What happens
By September 30	Your Medicare Advantage or Part D plan sends its Annual Notice of Change for next year.
Early October	Next year’s plans and prices appear in the Medicare Plan Finder.
October 15 to December 7	Open enrollment: join, switch or drop a Medicare Advantage or Part D plan.
January 1	Your new coverage starts.
January 1 to March 31	Medicare Advantage open enrollment: if you’re in a Medicare Advantage plan, you can make one switch.

What can you change during open enrollment?

Switch from Original Medicare to a Medicare Advantage plan, or back.
Switch from one Medicare Advantage plan to another.
Join, switch or drop a Part D prescription drug plan.

Joining a new plan generally ends your old one automatically, so you don’t need to cancel first. Medigap (Medicare Supplement) policies aren’t part of open enrollment. More on that below.

If you’re joining Part D after going without creditable drug coverage, a late enrollment penalty may be added to your premium. The Medicare late enrollment penalty calculator estimates it.

Step 1: Read your Annual Notice of Change

Your plan’s Annual Notice of Change lists what’s different next year: the premium, deductible, copays, drug list (formulary), pharmacy network and, for Medicare Advantage, the doctor and hospital network. Look for:

Drugs you take that are dropped from the list or moved to a higher cost tier.
New prior authorization or step therapy rules on your drugs.
Doctors, hospitals or pharmacies leaving the network.
A higher premium or deductible.

If nothing important changed and the plan still works for you, staying put is fine. If something did, compare plans.

Step 2: List your drugs, doctors and pharmacies

Before you compare, write down:

Every prescription, with the dose and how often you take it.
The doctors and hospitals you want to keep.
Your preferred pharmacy, and whether you’d use mail order.

The Medicare Plan Finder on Medicare.gov uses your drug list to estimate each plan’s total yearly cost, including premiums, the deductible and copays.

Step 3: Compare the total cost, not the premium

A $0-premium plan can cost more over a year than one with a premium, once you add the deductible and your copays. Compare plans on:

Premium × 12
Deductible
Drug costs for your list at your pharmacy
Copays for the care you expect to use
For Medicare Advantage, the out-of-pocket maximum for in-network care

Remember that you still pay the Part B premium when you’re in a Medicare Advantage plan. For 2026, the standard Part B premium is $202.90 a month, and higher earners pay more (see below). Medicare usually announces next year’s Part B premium in the fall.

Step 4: Check the Part D rules for next year

Part D drug coverage has changed a lot since 2025:

Out-of-pocket cap: your costs for covered Part D drugs are capped at $2,400 in 2027, up from $2,100 in 2026. Premiums don’t count toward the cap.
Deductible: plans can charge a deductible of up to $700 in 2027 ($615 in 2026). Some charge less or none.
Insulin: covered insulin costs no more than $35 for a month’s supply.
Vaccines: recommended adult vaccines covered by Part D, such as shingles, cost you nothing.
Payment plan: the Medicare Prescription Payment Plan lets you pay your drug costs in monthly amounts over the year instead of all at once at the pharmacy. Ask your plan how to join.

The Medicare Part D calculator estimates your 2027 drug costs under these rules, shows the month you’d reach the cap and what the payment plan’s monthly bills would be.

Step 5: Medicare Advantage or Original Medicare?

Medicare Advantage plans often have lower premiums and extras such as dental, vision and hearing coverage, but they use networks and often require prior authorization. Check:

Are your doctors and hospitals in the network, and will they be all year?
What’s the out-of-pocket maximum?
Do you travel or spend part of the year in another state?

Original Medicare lets you see any provider that accepts Medicare nationwide. Most people pair it with a Part D plan and a Medigap policy to cover deductibles and coinsurance.

Be careful switching back to Original Medicare. Outside your first Medigap enrollment period, insurers in most states can ask health questions and turn you down or charge more. Some states give extra rights. Check with your state’s insurance department or SHIP before you give up a Medigap policy or move away from one.

Step 6: Check your IRMAA

Higher-income beneficiaries pay an extra amount, called IRMAA, on top of the Part B premium and any Part D premium. It’s based on your tax return from two years earlier:

2026 premiums use your 2024 income. In 2026, IRMAA starts above $109,000 of modified AGI for individuals and $218,000 for joint filers. See all the levels on our 2026 IRMAA brackets page.
2027 premiums will use your 2025 income. CMS publishes next year’s brackets in the fall.
2028 premiums will use your 2026 income, so a Roth conversion or large capital gain before December 31 can raise your premiums two years from now.

IRMAA is the same whichever plan you choose: the Part D surcharge applies to Medicare Advantage plans with drug coverage too. Use the IRMAA calculator to see your bracket and how close you are to the next one.

If your income has dropped because you retired, cut back your hours, married, divorced or lost a spouse, you can ask Social Security to use a more recent year. Our guide on how to appeal IRMAA explains Form SSA-44.

Step 7: See if you qualify for help paying

Extra Help (the Part D Low-Income Subsidy) lowers drug plan premiums, deductibles and copays for people with limited income and savings. Apply through Social Security.
Medicare Savings Programs, run by your state’s Medicaid office, can pay your Part B premium and sometimes your deductibles and coinsurance.

The income and asset limits change each year and vary by state, so apply if you think you’re close.

Step 8: Make the change

You can enroll:

Online through the Medicare Plan Finder at Medicare.gov.
By calling 1-800-MEDICARE (1-800-633-4227).
Directly with the plan, on its website or by phone.

Keep the confirmation number and check the welcome letter and new member card that arrive before January 1. If you’re switching drug plans, make sure your prescriptions are on file at your pharmacy under the new plan.

Free, unbiased help is available from your State Health Insurance Assistance Program (SHIP). SHIP counselors don’t sell insurance.

If you miss December 7

January 1 to March 31: if you’re in a Medicare Advantage plan, you can switch to another one or return to Original Medicare and join a Part D plan, once.
Special enrollment periods open up after events such as moving, losing other coverage or qualifying for Extra Help.
Five-star plans: you can switch into a plan with a five-star quality rating once between December 8 and November 30.

Otherwise, you’ll have to wait until next fall.

Sources

Key terms

About this guide. This Calcvera guide was written by Hassan Arslan, first published September 26, 2026 and last reviewed October 22, 2026. It is general education, not financial, tax or legal advice. See our editorial policy or report an error.