Medicare Open Enrollment 2027: What's Changing

Every autumn, millions of people on Medicare receive a thick envelope, put it on the kitchen counter, and never open it.

That envelope is the Annual Notice of Change, and it tells you exactly how your plan is about to become a different plan. Different premium. Different drug list. Different network. Same name on the card.

Open Enrollment is the seven-week window when you can do something about it. Here's what's changing for 2027, and what's worth checking before December 7.

The Dates That Matter

September: Annual Notice of Change and Evidence of Coverage arrive. This is the document that tells you what your current plan is doing next year.

October 1: Plan details for the coming year become viewable, so you can start comparing before the window opens.

October 15: Open Enrollment opens. You can now make changes.

December 7: Open Enrollment closes. Your plan must receive the request by this date.

January 1: Whatever you chose takes effect.

January 1 to March 31: Medicare Advantage Open Enrollment, a narrower second window, only if you're already in an Advantage plan.

The one to circle: December 7. There's no grace period, and no appeal for having been busy.

What You Can Actually Change

Join, drop or switch a Medicare Advantage plan, with or without drug coverage.

Join, drop or switch a Part D drug plan if you're on Original Medicare.

Move from Original Medicare to Medicare Advantage.

Move from Medicare Advantage back to Original Medicare.

What this window does not do is guarantee you a Medigap policy. Supplement plans have their own medical underwriting rules outside your one-time guaranteed issue period, and that catches people who assume switching back to Original Medicare automatically restores a supplement. Check that before you move.

Five Things Changing for 2027

CMS finalized the Contract Year 2027 rules for Medicare Advantage and Part D. The changes that matter to you, rather than to plan administrators:

1. The Part D Base Beneficiary Premium Is $41.33

That's the national base figure for 2027, published by CMS. What you pay varies by plan, and higher earners pay an income-related surcharge on top.

2. The Premium Stabilization Cap Is Ending

CMS's Part D Premium Stabilization Demonstration, a temporary program that had limited the annual increase in the base beneficiary premium to roughly 6%, ended after 2026. The 2027 base premium reflects that cap's expiration, not an ongoing ceiling, so plan premiums may rise more than they did in recent years.

3. The Coverage Gap Phase Is Gone

Since 2025, under the Inflation Reduction Act's Part D redesign, CMS has codified the elimination of the coverage gap, what people spent years calling the doughnut hole. The benefit structure is now simpler to follow, which is a genuine improvement for anyone who ever tried to work out which phase they were in.

4. No Cost Sharing Once You Reach the Catastrophic Phase

Combined with a reduced annual out-of-pocket threshold, this materially changes the picture for anyone on high-cost medications. If your drug spending is significant, this is the single change most worth understanding in detail.

5. Plan Comparison Should Get Less Noisy

CMS is removing 12 Star Ratings measures focused on administrative processes where beneficiaries couldn't meaningfully tell plans apart, and adding a depression screening and follow-up measure from the 2027 measurement year. Fewer, more meaningful signals when you compare.

The Seven Checks Worth Making

1. Read the Annual Notice of Change

Ten minutes with the document that arrived in September tells you most of what you need. Look specifically at the premium, the deductible, and whether your drugs moved tiers.

2. Check the Formulary Against Your Actual Prescriptions

List every medication you take, including doses, and confirm each one is still covered and still on the same tier. A plan that saves you $20 a month and moves one drug to a higher tier is not saving you anything.

3. Confirm Your Doctors Are Still in Network

Networks change annually. Confirm with the plan and with the practice, because directories are frequently out of date. This matters most in Medicare Advantage, where out-of-network care can be expensive or simply not covered.

4. Compare Total Annual Cost, Not the Premium

Premium plus deductible plus expected copays plus coinsurance. The lowest-premium plan is regularly the most expensive one overall for someone with ongoing prescriptions or frequent appointments.

5. Check the Pharmacy Network

Preferred pharmacies cost less than standard ones within the same plan. If your pharmacy dropped out of the preferred tier, your costs went up without the plan appearing to change at all.

6. Look at the Out-of-Pocket Maximum

Medicare Advantage plans have an annual cap. Original Medicare on its own does not, which is why most people pair it with a supplement. Know which protection you're relying on.

7. Check Whether Your Income Triggered a Surcharge

IRMAA runs on a two-year lookback, so 2025 income sets your 2027 premiums. A one-off event, such as a property sale, a large Roth conversion, or an inheritance, can push you into a higher bracket for a single year. If it was a one-time event and your circumstances have since changed, you can request a reconsideration.

Medicare Advantage or Original Medicare

The choice underneath the plan choice. Briefly:

Original Medicare plus Part D plus a supplement. Any provider who accepts Medicare, no referrals, predictable costs once the supplement is in place. Higher monthly outlay, and supplements can require underwriting if you don't buy during your guaranteed issue window.

Medicare Advantage. Often lower or zero premium, frequently bundles drug coverage plus dental, vision and hearing, and includes an out-of-pocket maximum. In exchange you accept a network, referrals in some plans, and prior authorization for some services.

Neither is better in the abstract. The honest question is whether you value provider freedom or lower predictable monthly cost more, and how much you travel. We cover the comparison properly in the Health articles.

Five Mistakes That Cost Real Money

1. Auto-Renewing Without Reading Anything

The most common and most expensive. Your plan changed; you didn't.

2. Choosing on Premium Alone

See check four. Total annual cost is the only number that means anything.

3. Assuming You Can Get a Supplement Back Later

Leaving Original Medicare for Advantage can be a one-way door in practice, because returning may require medical underwriting depending on your state and timing.

4. Confusing This Window with Your Initial Enrollment Period

Different thing entirely. The IEP at 65 is a seven-month window, and missing it without creditable employer coverage carries a permanent Part B late-enrollment penalty, a surcharge on every premium for life. Open Enrollment carries no such penalty.

5. Ignoring Dental, Vision and Hearing Until January

None are covered by Original Medicare. If you need them, that belongs in the comparison now, not as a surprise later.

Your October Checklist

Find the Annual Notice of Change and read the first two pages.

Write down every medication, dose and pharmacy.

List the doctors and specialists you want to keep.

Compare at least three plans on total annual cost using the official Plan Compare tool.

Call the plan to confirm the two or three things that matter most to you, and note who you spoke to.

Decide by the last week of November. Don't leave it to the first week of December.

Medicare's own yearly review guide walks through the same ground in a printable form if you'd rather work on paper.

Where This Sits in the Bigger Picture

Open Enrollment is an annual maintenance task. The larger question is what healthcare costs across a full retirement, and that number surprises people considerably more than a premium change does.

Two things worth sizing while you're already thinking about it. The healthcare cost calculator projects Medicare premiums, supplements and out-of-pocket spending through your planning horizon. The long-term care calculator covers the exposure Medicare doesn't touch at all, which is the one most retirees have no plan for.

If you want to see how both sit against your income, the retirement income calculator puts them in the same view.

Medicare decisions like these sits inside the bigger Finance Lens picture, where premiums and out-of-pocket costs become part of your full retirement budget. Start with the Finance Lens flow to see how coverage choices fit your income plan. The same choices also affect what you can pass on, which is where the Legacy Lens flow picks up.

Frequently Asked Questions

When is Medicare Open Enrollment for 2027 coverage?
October 15 to December 7, 2026, for coverage beginning January 1, 2027. Your plan must receive any change request by December 7.

What happens if I do nothing?
You're automatically re-enrolled in your current plan as it exists next year, with its new premium, new drug list and new network. Doing nothing is a choice to accept whatever changed.

What's the Part D premium for 2027?
The base beneficiary premium is $41.33. What you pay depends on your specific plan, and higher earners pay an income-related surcharge on top of it.

Is the doughnut hole gone?
The coverage gap phase was eliminated starting in 2025 and remains gone for 2027, along with a reduced out-of-pocket threshold and no cost sharing in the catastrophic phase. The benefit structure is simpler than it was.

Can I switch from Medicare Advantage back to Original Medicare?
Yes, during Open Enrollment. The complication is the supplement: buying a Medigap policy outside your guaranteed issue window may require medical underwriting, and you can be declined depending on your state and health.

Is this the same as signing up for Medicare at 65?
No. That's your Initial Enrollment Period, a seven-month window around your 65th birthday. Missing it without creditable employer coverage carries a permanent Part B penalty. Open Enrollment is only for changing existing coverage.

What if my income was unusually high two years ago?
IRMAA uses a two-year lookback, so a one-off event can raise your premium for a single year. If your circumstances have since changed. Retirement, a spouse's death, loss of income-producing property, you can request a reconsideration.

How do I compare plans?
Use the official Plan Compare tool on Medicare.gov, entering your actual medications and pharmacy. Compare total annual cost rather than premium, and confirm network status directly with your doctors.

Do I need to do this every year?
Yes, and it's worth the hour. Plans change annually and the plan that suited you last year may not this year, particularly if your prescriptions have changed.

What if I miss December 7?
You're generally locked in for the year. If you're in a Medicare Advantage plan, the January 1 to March 31 window gives you one more limited option. Certain life events also trigger a Special Enrollment Period.

One Hour, Once a Year

This is a small, boring, annual task that quietly determines a meaningful part of what you'll spend on healthcare next year.

Most people skip it because the envelope is thick and the deadline feels distant in October. Then December arrives and the decision gets made by default.

Put an hour in the calendar for the third week of October. That's genuinely all it takes.

Healthcare is one of five Lenses. Size the full cost against your plan, then check where the other four stand.

Medicare Open Enrollment 2027: What Changes and What to Check

Article