Medicare Annual Enrollment Period 2026: What Changes You Can Make and When
Medicare Annual Enrollment Period 2026: What Changes You Can Make and When
Every fall, millions of Medicare beneficiaries get a window to revisit their coverage — and most of them let it close without looking through it.
The Medicare Annual Enrollment Period (AEP) runs October 15 through December 7 each year. Any changes you make take effect January 1, 2026. It’s one of the most important financial decisions you’ll make all year, yet the rules around what you can and cannot change are widely misunderstood.
This guide will walk you through the full picture: what AEP covers, how it differs from other enrollment windows, what to look for when evaluating your plan, and the mistakes that cost beneficiaries real money every year.
AEP vs. OEP vs. SEP: Understanding the Three Enrollment Windows
Before diving into what you can change, it helps to understand that Medicare has three distinct enrollment periods — and they are not interchangeable.
Annual Enrollment Period (AEP) — October 15 to December 7
This is the main event. AEP is the one time each year when any Medicare beneficiary can make any plan change — no qualifying life event required. Changes effective January 1.
Open Enrollment Period (OEP) — January 1 to March 31
This window is often confused with AEP, but it’s far more limited. During OEP, you can:
- Switch from one Medicare Advantage plan to another
- Drop a Medicare Advantage plan and return to Original Medicare (with or without a Part D plan)
What you cannot do during OEP: switch from Original Medicare to Medicare Advantage, or make any changes to a standalone Part D drug plan.
Special Enrollment Period (SEP)
SEPs are triggered by qualifying life events — moving to a new service area, losing employer coverage, entering or leaving a nursing facility, or losing Medicaid eligibility, among others. SEPs are narrow and time-sensitive. If you miss the window (typically 60 days), you may have to wait until AEP.
The bottom line: If you want maximum flexibility to change your coverage, AEP is your window. Don’t confuse it with OEP, and don’t assume a SEP will be available when you need it.
What You CAN Change During AEP
During the Annual Enrollment Period, you have broad flexibility. Specifically, you can:
- Switch from Original Medicare (Parts A & B) to a Medicare Advantage plan (Part C)
- Switch from Medicare Advantage back to Original Medicare
- Switch from one Medicare Advantage plan to a different Medicare Advantage plan — even across carriers
- Join a standalone Medicare Part D prescription drug plan if you don’t currently have one
- Switch from one Part D plan to another
- Drop your Part D plan entirely (though this is rarely advisable — late enrollment penalties apply if you go without creditable drug coverage)
One important note: Medicare Supplement (Medigap) plans are not part of AEP. You can apply for a Medigap plan at any time of year, but outside of your initial 6-month Medigap Open Enrollment window (which starts when you turn 65 and enroll in Part B), you may be subject to medical underwriting. This is a critical distinction that catches many beneficiaries off guard.
What You CANNOT Change During AEP
Just as important as knowing what’s allowed is knowing what isn’t:
- You cannot change your Medicare Supplement (Medigap) plan through AEP — Medigap has its own separate rules
- You cannot enroll in Medicare Part A or Part B for the first time during AEP — that requires the Initial Enrollment Period or a Special Enrollment Period
- You cannot retroactively change coverage — decisions made during AEP take effect January 1, not before
- You cannot make changes after December 7 without a qualifying SEP
The 5 Most Common AEP Mistakes — and How to Avoid Them
1. Auto-Renewing Without Reviewing
Your current plan will automatically renew if you do nothing. The problem? Plans change every year — premiums, copays, drug formularies, provider networks, and extra benefits are all subject to revision. What worked well this year may not be the best value next year.
Action: Read your Annual Notice of Change (ANOC), which your plan is required to mail you by September 30. Don’t file it away unread.
2. Focusing Only on the Premium
A $0-premium Medicare Advantage plan sounds attractive — until you’re hit with a $400 specialist copay or discover your preferred cardiologist is out of network. Total cost of ownership matters far more than the monthly premium.
Look at: Maximum out-of-pocket (MOOP), specialist and hospital copays, and whether your doctors are in-network.
3. Ignoring the Drug Formulary
If you take prescription medications, the formulary — the list of covered drugs and their tier placement — can mean hundreds or thousands of dollars in annual cost differences between plans.
Action: Use Medicare’s Plan Finder tool at Medicare.gov to enter your specific medications and compare actual out-of-pocket drug costs across plans in your area.
4. Assuming Your Doctor Is Still In-Network
Provider networks change annually. A physician who was in your plan’s network last year may not be this year. If you have established relationships with specific doctors or specialists, verify their network status before renewing or switching.
5. Waiting Until the Last Minute
AEP closes on December 7 — hard stop. If you wait until the final week and encounter enrollment errors, processing delays, or simply need more time to compare options, you’re out of luck until the following year.
How to Evaluate Whether to Switch Plans
A plan change should be driven by your actual healthcare needs, not marketing materials or a neighbor’s recommendation. Here’s a structured way to think through it:
Step 1: Review Your Current Costs
Pull your Explanation of Benefits (EOB) statements from the past 12 months. What did you actually spend on copays, coinsurance, and prescriptions? How does that compare to your premium?
Step 2: Check What’s Changing in Your Current Plan
Your ANOC will detail every change to your plan for the upcoming year. Pay particular attention to:
- Premium changes (Part B is $202.90/month in 2026)
- Changes to your drug formulary or tier structure
- Network changes
- Changes to extra benefits (dental, vision, hearing, fitness)
Step 3: Compare the Maximum Out-of-Pocket
In 2026, the maximum out-of-pocket (MOOP) for Medicare Advantage in-network costs is $9,250. This is the ceiling on what you’ll pay before the plan covers 100% of in-network costs. Plans with lower MOOPs provide more financial protection — but often come with higher premiums. Know your risk tolerance.
Step 4: Run the Drug Cost Comparison
Log into Medicare.gov’s Plan Finder, enter your zip code, and input every medication you take. The tool will calculate your estimated annual drug costs for each plan. This step alone can reveal significant cost differences.
Step 5: Evaluate the Network
If you have preferred providers — a primary care physician you trust, a specialist managing a chronic condition, a specific hospital system — confirm they are in-network under any plan you’re considering.
Cost Considerations: What to Look at Beyond the Premium
Here’s a quick-reference breakdown of the key cost factors to evaluate during AEP:
| Cost Factor | What to Look For |
|---|---|
| Monthly Premium | Your baseline cost; $0 plans exist but aren’t always the best value |
| Part B Premium | $202.90/month in 2026 for most beneficiaries (IRMAA may apply) |
| Deductibles | Part D max deductible is $615 in 2026; some plans waive it |
| Copays & Coinsurance | Specialist, ER, and hospital copays vary widely across plans |
| MOOP (In-Network) | $9,250 maximum for MA plans in 2026 |
| Part D OOP Cap | $2,100 maximum for prescription drug costs in 2026 |
| Drug Formulary | Tier placement of your specific medications determines your cost |
| Extra Benefits | Dental, vision, hearing, gym memberships — compare what’s actually usable |
When to Call an Independent Medicare Advisor
Medicare.gov’s Plan Finder is a powerful tool, but it can’t replace personalized guidance — especially if your situation involves:
- Multiple chronic conditions with complex medication regimens
- Upcoming procedures or surgeries that require specific specialists or facilities
- Recent relocation to a new service area
- Coordination with employer, retiree, or VA coverage
- IRMAA concerns if your income has changed significantly
An independent Medicare advisor — one who works with multiple carriers rather than representing a single plan — can compare options across the full market and help you model total annual cost, not just the monthly premium. There is no cost to you for this service; advisors are compensated by the carriers.
The difference between working with a captive agent (who represents one carrier) and an independent broker (who represents many) can be the difference between finding the right plan and finding the right plan for their quota.
The Bottom Line
The Annual Enrollment Period is your most powerful tool for managing Medicare costs — but only if you use it intentionally. Auto-renewing without reviewing, fixating on the premium, and ignoring the formulary are the three mistakes that cost beneficiaries the most money year after year.
AEP runs October 15 through December 7. Changes take effect January 1. The time to start preparing is now.
If you’d like help evaluating your current plan or comparing your options for 2026, we’re here to walk through it with you — no pressure, no obligation.
👉 Explore Medicare Options → 👉 Read our Medicare FAQ →
Rodney Cummings | Legacy Wealth Services | OR License #18847712 | 503-832-8555 | Happy Valley, OR
This content is for educational purposes only and does not constitute personalized insurance or financial advice. Plan availability, premiums, and benefits vary by location and are subject to change annually.