The Medicare Annual Enrollment Period (AEP) for 2026 coverage runs from October 15 to December 7, 2025. Any changes you make take effect January 1, 2026. If you are already on Medicare, this is your main window each year to switch plans, drop coverage, or add a Part D drug plan. Missing this window means you are likely locked into your current coverage for the full calendar year.
This guide covers exactly what you can change during AEP, what you cannot change, and how to prepare before October 15.
What Is the Medicare Annual Enrollment Period?
AEP is a federally mandated annual window established by CMS (Centers for Medicare and Medicaid Services) during which Medicare beneficiaries can make changes to their Part C (Medicare Advantage) and Part D (prescription drug) coverage. It is not the same as the Initial Enrollment Period for new Medicare enrollees, and it is separate from the Medicare Advantage Open Enrollment Period (MA OEP) that runs January 1 through March 31.
The 2026 AEP dates:
| Period | Start | End | Changes Effective |
|---|
| Annual Enrollment Period (AEP) | October 15, 2025 | December 7, 2025 | January 1, 2026 |
| MA Open Enrollment Period (MA OEP) | January 1, 2026 | March 31, 2026 | First of following month |
| General Enrollment Period (Part B) | January 1, 2026 | March 31, 2026 | July 1, 2026 |
What You Can Change During AEP 2026
During the 2026 Annual Enrollment Period, you can make any of the following changes:
Switch between Original Medicare and Medicare Advantage
- Drop your Medicare Advantage plan and return to Original Medicare (Parts A and B)
- Enroll in a Medicare Advantage (Part C) plan from Original Medicare
Change your Medicare Advantage plan
- Switch from your current Medicare Advantage plan to a different Medicare Advantage plan
- This includes switching from an HMO to a PPO, or changing networks entirely
Change your Part D prescription drug plan
- Enroll in a Part D plan if you did not when you first became eligible
- Switch from your current Part D plan to a different one
- Drop a standalone Part D plan (note: this may trigger a late enrollment penalty if you go without creditable coverage)
Add or drop supplemental drug coverage
- If you are in a Medicare Advantage plan that includes drug coverage (MAPD), you can switch to a plan that does or does not include drug coverage
What You Cannot Change During AEP 2026
AEP does not cover everything. These changes are NOT available during the annual enrollment window:
- Medigap (Medicare Supplement) plans. In most states, you cannot enroll in a new Medigap plan during AEP on a guaranteed-issue basis. Medigap enrollment is generally guaranteed-issue only during your initial 6-month Medigap open enrollment window (when you first enroll in Part B at age 65 or older). After that, insurers can apply medical underwriting.
- Original Medicare Parts A and B. If you are not yet enrolled, AEP is not the signup window. Use the Initial Enrollment Period (IEP) around your 65th birthday or the General Enrollment Period (January 1 to March 31).
- Dental, vision, or hearing coverage outside of a Medicare Advantage plan. These are not covered by Original Medicare, and AEP does not expand that.
Key 2026 Medicare Plan Changes to Know Before You Enroll
Several significant changes to Medicare benefits took effect or continue into 2026. Reviewing them before AEP opens could affect which plan is right for you.
Part D Out-of-Pocket Cap: $2,100 in 2026
The Inflation Reduction Act restructured Part D costs. In 2025, the annual out-of-pocket cap for prescription drugs was $2,000. For 2026, that cap increases to $2,100, according to CMS Part D guidance. Once you reach $2,100 in covered drug costs in a year, you pay $0 for covered prescriptions for the rest of the calendar year.
2026 Part D cost structure:
| Phase | Your Cost | Ends When |
|---|
| Deductible phase | 100% of drug costs | You pay up to $615 (2026 maximum deductible) |
| Initial coverage phase | Plan copays or coinsurance | Out-of-pocket spending reaches $2,100 |
| Catastrophic phase | $0 | End of calendar year |
The maximum Part D deductible in 2026 is $615, up from $590 in 2025. Not all plans charge the maximum deductible, so compare carefully during AEP.
Negotiated Drug Prices Starting 2026
The federal government negotiated lower prices on 10 high-cost Part D drugs. These negotiated prices take effect in 2026 and cover drugs used for autoimmune diseases, cancer, diabetes, and heart conditions. If you take any of those medications, your 2026 plan costs could be meaningfully lower. This is another reason to shop plans actively this AEP rather than auto-renewing.
Some Medicare Advantage Plans Are Exiting Markets
Each year, insurance carriers can withdraw from certain service areas. For 2026, some carriers announced they are reducing plan offerings or leaving specific markets. If your current Medicare Advantage plan is discontinued, you will receive a notice and have a Special Enrollment Period (SEP) to select a new plan. The SEP for involuntary plan termination runs December 8 through the end of February. You may also have guaranteed-issue rights to purchase a Medigap policy within 63 days of losing your MA coverage.
Do not wait for a termination notice. Use AEP proactively to compare alternatives.
How to Apply and Compare Plans During Medicare AEP 2026
Follow these steps when the Annual Enrollment Period opens on October 15, 2025.
- Gather your current plan documents. Find your Summary of Benefits, Evidence of Coverage, and Annual Notice of Change (ANOC). Plans must mail ANOCs by September 30 each year, two weeks before AEP opens.
- List your current prescriptions. Write down every medication, dose, and frequency. Drug formularies change year to year.
- Check the Medicare Plan Finder at medicare.gov/plan-compare. This official CMS tool shows available plans in your ZIP code, estimates your total annual costs based on your drug list, and shows plan ratings (1 to 5 stars).
- Compare total costs, not just premiums. A $0 premium plan may have higher copays, deductibles, or out-of-network costs than a plan with a modest monthly premium.
- Verify your doctors and pharmacies are in-network. If you have a preferred cardiologist, primary care doctor, or specialist, confirm they are in the plan's 2026 network before you enroll.
- Enroll or switch before December 7, 2025. Call the plan directly, use medicare.gov, or call 1-800-MEDICARE (1-800-633-4227) to complete your enrollment.
- Confirm your enrollment. You should receive a new member ID card and welcome packet before January 1.
Documents you may need to have ready:
- Medicare card (shows your Medicare number and Parts A and B dates)
- Current insurance card (if on a Medicare Advantage or Part D plan)
- List of all current prescriptions
- Name and NPI numbers of your primary care doctor and any specialists
- Your preferred pharmacy name and ZIP code
Common reasons Medicare plan changes get rejected or cause problems:
- Enrolling after December 7 (too late for AEP, changes will not take effect January 1)
- Choosing a plan where your current doctors are out-of-network
- Not reviewing the annual formulary change. A drug covered this year may not be covered next year at the same tier
- Confusing AEP with the Initial Enrollment Period (IEP). If you are not yet enrolled in Medicare Part A and B, AEP does not apply to you
- Dropping Part D without creditable alternative coverage (triggers late enrollment penalty: 1% of national base beneficiary premium per month you went without coverage)
Other Medicare Enrollment Periods to Know in 2026
AEP is the main window, but it is not the only one. Here is a quick overview of other 2026 enrollment windows per medicare.gov:
| Enrollment Period | Dates | Who It Is For |
|---|
| Initial Enrollment Period (IEP) | 7-month window around your 65th birthday | New Medicare enrollees |
| General Enrollment Period (GEP) | January 1 to March 31, 2026 | Late Part B enrollees; coverage starts July 1 |
| MA Open Enrollment Period (MA OEP) | January 1 to March 31, 2026 | Current MA enrollees who want to switch or drop |
| Special Enrollment Periods (SEPs) | Triggered by qualifying life events | Plan termination, moving, losing employer coverage |
| Annual Enrollment Period (AEP) | October 15 to December 7, 2025 | All Medicare beneficiaries reviewing 2026 coverage |
The MA Open Enrollment Period is often confused with AEP. The MA OEP only allows you to make one change: switch from your current Medicare Advantage plan to a different MA plan or return to Original Medicare. You cannot use the MA OEP to enroll in MA from Original Medicare for the first time.
Should You Review Your Medicare Plan Every Year?
Yes. Plans change their premiums, deductibles, drug formularies, and provider networks annually. A plan that was right for you in 2025 may no longer be optimal in 2026 given:
- Your health needs changed
- Your prescriptions changed
- Your plan's formulary changed (a drug moved to a higher cost tier)
- A better plan entered your market
- Your current plan is leaving your area
KFF research consistently finds that most Medicare beneficiaries do not shop their coverage during AEP. Many end up paying more than they need to. Taking 30 minutes to compare plans on medicare.gov each October can save hundreds of dollars per year.
Check Your Full Medicare Eligibility at CoveredUSA
If you are approaching 65 or supporting a family member who is, understanding the full picture of Medicare eligibility matters before AEP opens. Medicare covers people 65 and older, as well as people under 65 with certain disabilities or End-Stage Renal Disease (ESRD).
Not sure whether you qualify for Medicare, Medicaid, a Medicare Savings Program, or subsidized coverage through the ACA marketplace? The CoveredUSA eligibility screener walks you through your options in about 2 minutes. Check your eligibility now at CoveredUSA. It takes 2 minutes.
For more detail on Medicare eligibility rules, visit our Medicare eligibility guide.
Frequently Asked Questions
When is the Medicare Annual Enrollment Period in 2026?
The Medicare Annual Enrollment Period for 2026 coverage ran from October 15 to December 7, 2025. Any changes you made during that window took effect January 1, 2026. If you missed AEP, you may qualify for the MA Open Enrollment Period (January 1 to March 31, 2026) or a Special Enrollment Period.
Can I enroll in Medicare for the first time during AEP?
No. AEP is for people already enrolled in Medicare who want to change their Part C or Part D coverage. If you are new to Medicare, you enroll during your Initial Enrollment Period, which is a 7-month window centered on your 65th birthday.
Can I switch to a Medigap plan during Medicare AEP?
Generally no. In most states, Medigap plans are only guaranteed-issue during your 6-month Medigap Open Enrollment Period when you first enroll in Part B. After that, insurers can reject you or charge more based on your health history. Some states have additional protections. Check with your State Health Insurance Assistance Program (SHIP) for state-specific rules.
What is the Part D out-of-pocket cap for 2026?
The 2026 Medicare Part D annual out-of-pocket cap is $2,100, up from $2,000 in 2025. Once you hit $2,100 in covered drug costs in a calendar year, you pay $0 for covered prescriptions for the rest of the year. The maximum Part D deductible in 2026 is $615.
What happens if my Medicare Advantage plan leaves my area?
If your plan is discontinued or exits your service area, you will receive a notice and automatically qualify for a Special Enrollment Period. This SEP lets you enroll in a new Medicare Advantage plan or return to Original Medicare. You also have guaranteed-issue rights to purchase a Medigap policy within 63 days of your MA coverage ending.
What is the difference between AEP and the MA Open Enrollment Period?
AEP (October 15 to December 7) is the broader annual window where all Medicare beneficiaries can make plan changes. The MA Open Enrollment Period (January 1 to March 31) is narrower. It only allows current Medicare Advantage enrollees to make one change: switch plans or return to Original Medicare. You cannot enroll in Medicare Advantage for the first time during the MA OEP.
Can I still make Medicare changes outside of AEP?
Yes, through Special Enrollment Periods. SEPs are triggered by qualifying events such as moving to a new service area, losing employer-sponsored coverage, losing Medicaid eligibility, or your plan being discontinued. Contact 1-800-MEDICARE or visit medicare.gov to find out if you qualify for an SEP.
Where can I compare Medicare plans for 2026?
Use the Medicare Plan Finder at medicare.gov/plan-compare. Enter your ZIP code and drug list to see estimated annual costs for each available plan in your area. You can also call 1-800-MEDICARE (TTY 1-877-486-2048) for free, unbiased help.
