AEP 2027 Survival Guide: Key Medicare Deadlines to Know
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AEP 2027 Survival Guide: Key Medicare Deadlines to Know
Medicare Open Enrollment — often called the Annual Enrollment Period (AEP) — ends December 7, 2026. During the October 15–December 7 window, you can join, drop, or switch a Medicare Advantage or Medicare Part D drug plan, or change between Original Medicare and Medicare Advantage. Changes generally take effect January 1, 2027.
If you miss the deadline, your later options depend on your coverage and circumstances. People enrolled in Medicare Advantage have one additional change opportunity from January 1 through March 31, and some beneficiaries qualify for a Special Enrollment Period.
Medicare’s annual open enrollment period (AEP) runs from October 15–December 7 each year. This means that if you want to make a change during AEP for 2027, the plan must receive your request by December 7, 2026.
During open enrollment, millions of Medicare beneficiaries have the opportunity to make changes to their coverage. This matters heading into 2027 because plans change every year — a plan that was the best value in 2026 may not be in 2027.
The good news is that keeping track of the major deadlines is easier when you have them in one place. This guide walks you through the key dates in order.
Key Medicare Deadlines for 2027 Coverage
| Deadline | What It Is | Who It Applies To | When Changes Take Effect |
|---|---|---|---|
| By September 30, 2026 | Annual Notice of Change (ANOC) arrives in print or electronically | Medicare Advantage and stand-alone Part D enrollees | N/A — review it before AEP |
| October 1, 2026 | 2027 plan details can be marketed and previewed | Anyone comparing plans | N/A |
| October 15, 2026 | AEP begins | People eligible to make Medicare health or drug plan changes | Jan. 1, 2027 |
| December 7, 2026 | AEP ends — last day for AEP enrollment requests | People eligible to make Medicare health or drug plan changes | Jan. 1, 2027 |
| January 1, 2027 | New coverage and plan changes begin | People who made an AEP change | — |
| January 1–March 31, 2027 | Medicare Advantage Open Enrollment Period (MA OEP); one change allowed | People already enrolled in a Medicare Advantage plan | First of the month after the plan receives the request |
| January 1–March 31, 2027 | General Enrollment Period (GEP) for Part B and premium Part A | People who missed their Initial Enrollment Period and do not qualify for a Special Enrollment Period | First of the month after enrollment |
For a full calendar of dates, see our guide to important Medicare dates.
September 2026: Read Your Annual Notice of Change
Your survival guide starts before AEP opens. Medicare Advantage and stand-alone Medicare prescription drug plans must send enrollees an Annual Notice of Change by September 30. Depending on your delivery preference, you may receive it in print or electronically.
It is important to read it. This document summarizes important changes in coverage, costs, and other plan terms that take effect in January. In particular, look for changes to your premium and deductible, as well as whether your medications remain covered and your pharmacies and providers remain in-network. Formularies and provider networks can also change during the plan year under Medicare rules, so continue reviewing notices from your plan.
If you have not received your ANOC in print or electronically by September 30, or if you discarded it, contact your plan and request a copy.
October 15, 2026: AEP Opens
Starting October 15, you can join, switch, or drop a Medicare Advantage or Part D drug plan. During AEP you can:
- Switch from Original Medicare to a Medicare Advantage plan, or the reverse
- Change from one Medicare Advantage plan to another
- Join, switch, or drop a stand-alone Part D prescription drug plan
You generally do not need to wait until December. Comparing plans early gives you time to verify your doctors are in-network and your prescriptions are on the formulary — and to get help if you need it.
You may be perfectly happy with the plan you have today. But just because you’re satisfied with your coverage doesn’t mean you shouldn’t look into different options. You won’t know if there’s a cheaper alternative to your Part D plan, for example, if you don’t look. Comparing total estimated annual costs may reveal a lower-cost option, depending on your prescriptions, pharmacies, providers, and location. Before you finalize anything, review the biggest AEP mistakes to avoid.
December 7, 2026: AEP Closes
This is the main annual deadline. To make a change during AEP, the new plan must receive your enrollment request by December 7, 2026. There is no routine extension of the AEP deadline, although some people may qualify for a Special Enrollment Period.
If you have a stand-alone Part D plan and do not qualify for another enrollment opportunity, you generally must wait until the next AEP to change plans. If you are enrolled in Medicare Advantage, you have one additional change opportunity from January 1 through March 31. Other enrollment rights may apply in certain circumstances, including a move, loss of other coverage, a qualifying plan change, or the availability of an eligible 5-star plan.
January 1, 2027: New Coverage Begins
Any change you made during AEP takes effect January 1. Watch for your new member ID card, and bring it to your first appointment and pharmacy visit of the year. If you switched plans, confirm the new plan’s billing or premium-deduction arrangement; premiums may be billed directly or withheld from Social Security or Railroad Retirement Board payments.
January 1 – March 31, 2027: Two More Windows
Medicare Advantage Open Enrollment Period (MA OEP). If you’re already in a Medicare Advantage plan and realize in January that it isn’t working, you get one chance to make a change. During the MA OEP, you can switch to another Medicare Advantage plan or drop Medicare Advantage, return to Original Medicare, and join a stand-alone Part D plan if needed. Your new coverage starts the first of the month after the plan receives your request.
General Enrollment Period (GEP). If you missed your Initial Enrollment Period, need Part B or premium Part A, and do not qualify for a Special Enrollment Period, the GEP is your chance to sign up. Coverage begins the first of the month after you enroll. Late penalties may apply. The Part B penalty generally lasts as long as you have Part B, while the premium-Part A penalty generally lasts for twice the number of years you delayed enrollment.
Deadlines That Depend on You
Not every Medicare deadline follows the calendar. Three important enrollment periods depend on your circumstances:
Your Initial Enrollment Period (IEP). If you’re turning 65 in 2027, your IEP is generally the 7-month window that starts 3 months before your birthday month and ends 3 months after it. If your birthday is on the first day of the month, the window shifts one month earlier: it starts 4 months before your birthday month and ends 2 months after it. Enrolling at the right time — or using a Special Enrollment Period when eligible — can help you avoid coverage gaps and possible late-enrollment penalties.
Your Medigap Open Enrollment Period. This is the one-time, 6-month window that begins the first month you’re 65 or older and enrolled in Part B. During this window, you can buy any Medicare Supplement (Medigap) policy an insurer offers in your state without medical underwriting based on your health. After it ends, insurers in most states may decline your application or charge more based on your health unless you have a guaranteed-issue right. Some states provide stronger protections.
Special Enrollment Periods (SEPs). Certain events — moving out of your plan’s service area, losing other coverage, or your plan terminating — may open a window to make changes outside AEP. The timing and permitted changes vary by circumstance, so check your specific rules as soon as the event happens.
One Last Survival Tip: Compare Official Sources and Get Help if Needed
Medicare is a national program, but Medicare Advantage, stand-alone Part D, and Medigap choices vary by location. In addition to using Medicare Plan Finder, you may find it helpful to speak with a local Medicare insurance agent or your State Health Insurance Assistance Program (SHIP).
A knowledgeable local professional may be familiar with area plan networks and pharmacies, but always verify your doctors, prescriptions, pharmacy costs, and total estimated annual costs with the plan or Medicare Plan Finder. There is typically no direct fee to you for an agent’s help, but agents may be paid by insurers and may not represent every plan. SHIP offers free, personalized counseling and is not affiliated with an insurance company or health plan.
FAQ
Q: When is the Medicare AEP for 2027 coverage?
The Annual Enrollment Period runs from October 15 through December 7, 2026. Any enrollment or plan change made during this window takes effect January 1, 2027.
Q: What happens if I miss the December 7 deadline?
Your options depend on your coverage. If you have a stand-alone Part D plan and do not qualify for another enrollment opportunity, you generally must wait until the next AEP. If you are enrolled in Medicare Advantage, you can make one change during the Medicare Advantage Open Enrollment Period from January 1 through March 31. You may also qualify for a Special Enrollment Period.
Q: Can I change my Medicare plan after December 7?
In some cases, yes. If you have Medicare Advantage, you can use the Medicare Advantage Open Enrollment Period from January 1 through March 31, 2027 to make one plan change. You may also qualify for a Special Enrollment Period based on a qualifying life event, such as moving or losing other coverage.
Q: When should I receive my Annual Notice of Change?
Your plan must send your Annual Notice of Change in print or electronically by September 30. If you did not receive it or misplaced it, contact your plan directly and request a copy before AEP ends on December 7.
Q: Do these deadlines apply to Medicare Supplement (Medigap) plans?
No. Medigap plans are not tied to AEP — you can apply for one at any time of year. However, outside your 6-month Medigap Open Enrollment Period or a guaranteed-issue window, insurers in most states can use medical underwriting to decline your application or charge more. Some states provide additional protections.
Q: Can I compare plans without sharing my personal information?
Yes. Medicare’s Plan Finder allows you to continue without logging in and compare plans by ZIP code. The Association’s agent directory can also help you find local Medicare insurance agents; review the directory’s privacy disclosures before submitting information.
