Medicare Open Enrollment Ends December 7: 7 Things to Check Before It’s Too Late

Medicare open enrollment for 2027 coverage ends on December 7, 2026. Any change you make before then takes effect on January 1, 2027. If you do nothing, most plans simply renew — but your premium, your covered drugs, and your doctors can still change underneath you. A twenty-minute check now can save you a year of overpaying, or an ugly surprise at the pharmacy counter in January.

This is not the general explainer — for the full background, see our full guide to Medicare open enrollment for 2026–2027. This is the last-weeks checklist: the seven things worth checking before the Medicare open enrollment deadline December 7.

1. Read your Annual Notice of Change first

Your plan was required to send you an Annual Notice of Change, usually called the ANOC, in the fall. It is the one letter that tells you exactly what changes on January 1: your premium, your deductible, your copays, your covered drugs, and your pharmacy network.

If you threw it away, the same information is in your online plan account and on Medicare.gov’s Plan Finder. Do not skip this step. The plan you liked in 2026 is not automatically the same plan in 2027 — and the ANOC is where the changes are hiding.

2. Check every prescription against the 2027 drug list

This is the check that saves the most money. Plans change their drug lists, called formularies, every year. A drug that was covered in 2026 may need prior authorization in 2027, move to a more expensive tier, or drop off the list entirely.

Type each of your prescriptions into Medicare.gov’s Plan Finder and compare what you would actually pay month by month under each plan. If a drug is not covered, talk to your doctor now about whether a covered alternative works — not in January, when you are standing at the pharmacy counter.

3. Learn the 2027 Part D numbers before you choose

For 2027, Medicare’s prescription drug coverage has three numbers worth knowing. All three come from CMS, the federal agency that runs Medicare:

• The most a Part D plan can charge as a yearly deductible is $700, up from $615 in 2026.
• Your total out-of-pocket spending on covered Part D drugs is capped at $2,400 for the year, up from $2,100. Once your spending reaches that cap, you pay nothing more for covered Part D drugs for the rest of the year.
• The national base beneficiary premium — the benchmark CMS uses for Part D premiums — is $41.33 a month.

What that means in practice: if your plan charges the full $700 deductible, you pay the first $700 of drug costs yourself before coverage starts. And the $2,400 cap is a real safety net — but only for drugs your plan actually covers, which is why check 2 above still matters.

4. Make sure your doctors and hospitals are still in network

If you have a Medicare Advantage plan, your network can change on January 1. A doctor who was in network in 2026 may be out in 2027, and out-of-network care in many Advantage plans costs far more — or is not covered at all.

Check every doctor, specialist, and hospital you actually use, plus your preferred pharmacy. In Original Medicare, any doctor who accepts Medicare works, so this check matters most if you are in a Medicare Advantage plan.

5. Do not budget on a Part B premium that is not final yet

Here is a trap worth avoiding: some websites are already quoting a 2027 Part B premium of about $185 a month. That number has no CMS source behind it and does not match the official projection. Ignore it.

As of this writing, CMS has not announced the official 2027 Part B premium or deductible. The 2026 Medicare Trustees Report projects the standard premium at $209.50 a month for 2027, up $6.60 from $202.90 in 2026, with the deductible projected at $292, up from $283. That is a projection, not a bill — CMS usually announces the final number in November, and your exact amount should appear in your my Social Security account in late November.

For scale, Social Security’s 3.6% cost-of-living increase for 2027 lifts the average retired-worker’s benefit by about $75 a month, from $2,095 to $2,170. If the $209.50 projection holds, the Part B increase takes $6.60 of that raise. Plan around the projection; do not lock a budget to a number no official source has published.

6. Compare the whole year’s cost, not just the monthly premium

A $0-premium plan is not automatically the cheapest plan. Add up the full year before you choose.

Worked example: take a Part D plan with a $35 monthly premium. That is $420 a year in premiums. If the plan has the maximum $700 deductible and your prescriptions are not covered until you meet it, you have spent $1,120 before copays even start. A plan with a $50 premium — $600 a year — but no deductible on your generic drugs could easily cost less over the year, even though its premium looks higher. Medicare.gov’s Plan Finder does this math for you when you enter your drugs and pharmacy: use its estimated total yearly cost, not the premium alone.

7. Know what happens if you miss December 7

December 7 is a hard deadline for most changes. After it, you are generally locked into your 2027 coverage until next year’s open enrollment. Two narrow exceptions exist. A separate Medicare Advantage Open Enrollment Period runs January 1 to March 31, but it only lets people already in a Medicare Advantage plan switch plans or return to Original Medicare — it does not help if you missed joining a drug plan. And if a plan earns a 5-star rating, you can switch into it at certain times of year.

Do not count on the exceptions. If you are unsure, make the change before December 7. You can change your mind again any time before the deadline, and only your last choice counts.

What to do this week

• Find your Annual Notice of Change letter, or log in at Medicare.gov.
• Enter every prescription into Plan Finder and compare total yearly costs, not premiums.
• Confirm your doctors, hospital, and pharmacy are in network for 2027.
• Note the 2027 Part D numbers — a $700 maximum deductible and a $2,400 out-of-pocket cap — and the Part B projection of $209.50 a month.
• Make your choice before December 7. If you want free, unbiased help, your State Health Insurance Assistance Program (SHIP) offers free local counseling — find yours at shiphelp.org or call 1-800-MEDICARE (1-800-633-4227).

Frequently asked questions

When does Medicare open enrollment end in 2026?

Medicare open enrollment ends on December 7, 2026. Changes you make by then take effect on January 1, 2027.

What happens if I miss the December 7 Medicare deadline?

You are generally locked into your 2027 coverage until next year’s open enrollment. The main exceptions are the Medicare Advantage Open Enrollment Period (January 1 to March 31, only for people already in a Medicare Advantage plan) and switching into a 5-star rated plan at certain times of year.

What is the Medicare Part D deductible for 2027?

The maximum Part D deductible for 2027 is $700, up from $615 in 2026. The annual out-of-pocket cap for covered Part D drugs is $2,400, and the national base beneficiary premium is $41.33 a month. These figures come from CMS.

Has the 2027 Medicare Part B premium been announced?

No. As of this writing, CMS has not announced the official 2027 Part B premium or deductible. The 2026 Medicare Trustees Report projects the standard premium at $209.50 a month, up from $202.90, with the deductible projected at $292, up from $283. Your exact amount should appear in your my Social Security account in late November.

This article is general information, not financial or medical advice. Medicare rules and your plan’s details can change — verify your coverage and costs at Medicare.gov or by calling 1-800-MEDICARE, and consider free counseling from your state’s SHIP program before you decide.