5 Things to Know Before Medicare Open Enrollment Ends December 7

Each fall, Medicare beneficiaries have the opportunity to make changes to their health coverage during what is officially called the Annual Enrollment Period (AEP). This window opens on October 15 and closes on December 7—a period of just 54 days to evaluate your current plan and decide whether a change makes sense for the year ahead.

Whether you’re satisfied with your current coverage or considering a switch, understanding the rules, costs, and deadlines can help you avoid costly mistakes and ensure you have the protection you need.

1. The Enrollment Window Is Fixed: October 15 Through December 7

The dates for Medicare Open Enrollment do not change from year to year. Federal rules establish this period as October 15 through December 7 annually. Any changes you make during this window take effect on January 1 of the following year.

Your plan must receive your enrollment request by December 7 for your changes to take effect on January 1. If you make more than one change during this window, the last one you submit before the deadline is the one that counts.

It’s important to note that if you do nothing by December 7, you are automatically enrolled in your current plan’s version for the upcoming year. This means if your plan’s costs, drug formulary, or provider network have changed, you’ll be subject to those changes whether or not you reviewed them.

2. What You Can—and Cannot—Change During Open Enrollment

The Annual Enrollment Period gives Medicare beneficiaries the flexibility to make several types of coverage changes. During open enrollment, you can join, switch, or drop a Medicare Advantage Plan, join a new Medicare drug plan (Part D), switch from Medicare Advantage back to Original Medicare, or move from Original Medicare to a Medicare Advantage plan.

Actions Allowed During AEP

• Switch from one Medicare Advantage plan to another
• Switch from Medicare Advantage to Original Medicare
• Switch from Original Medicare to Medicare Advantage
• Join a standalone Part D prescription drug plan
• Switch Part D plans
• Drop Part D coverage (though this may result in penalties later)

If you switch to Original Medicare during open enrollment, you may need to join a separate Part D drug plan and may want to add a Medicare Supplement Insurance (Medigap) policy. However, there are limits on when you can add Medigap coverage outside of your initial enrollment window.

3. Medicare Costs Are Changing for 2026

Understanding how Medicare costs are changing can help you evaluate whether your current plan still makes financial sense. For 2026, Medicare has announced updates to premiums, deductibles, and cost-sharing across Original Medicare, Medicare Advantage, and prescription drug plans.

Part B Premium Increases

The standard monthly Medicare Part B (medical coverage) premium increased to $202.90 for 2026, up $17.90 from $185.00 in 2025—a 9.7% increase. Part B premiums are calculated on a sliding scale based on your adjusted gross income, meaning higher-income beneficiaries pay more.

The Part B annual deductible also increased from $257 in 2025 to $283 in 2026.

Part A Hospital Costs

While about 99% of Medicare beneficiaries don’t pay a Part A (hospital insurance) premium, the Part A hospital deductible climbed to $1,736 per benefit period in 2026, up from $1,676 in 2025. This deductible applies each time you’re admitted to the hospital after a benefit period ends.

Source: Centers for Medicare & Medicaid Services (CMS)

Some Good News on Drug Coverage

The average monthly premium for Medicare Advantage plans is projected to fall by $2.40 in 2026 to approximately $14.00. Average standalone Part D prescription drug plan premiums are also decreasing from $38.31 to $34.50 per month.

Additionally, the prescription drug out-of-pocket cap introduced under the Inflation Reduction Act continues to provide financial protection. For 2026, out-of-pocket costs for covered Part D prescription drugs are capped at $2,100, up from $2,000 in 2025.

4. Review Your Annual Notice of Change

Each fall, Medicare Advantage and Part D plans send beneficiaries an Annual Notice of Change (ANOC) document. This notice details any changes to your plan for the upcoming year, including modifications to premiums, deductibles, copayments, covered drugs, and provider networks.

Some Medicare Advantage insurers have exited certain markets or cut service areas for 2026, making it essential for every beneficiary to review their ANOC carefully. Even if you were happy with your plan last year, changes to the drug formulary could mean a medication you take is no longer covered—or costs significantly more.

What to Check in Your ANOC

• Changes to monthly premiums
• Modifications to the drug formulary (list of covered medications)
• Updates to the provider and pharmacy networks
• Changes to copays and coinsurance amounts
• Any new prior authorization requirements

5. Use the Medicare Plan Finder to Compare Options

The Medicare Plan Finder on Medicare.gov is the official comparison tool that shows every Medicare Advantage plan and Part D prescription drug plan available in your county. The tool allows you to enter your ZIP code, medications, and preferred pharmacies to compare available plans side by side.

The Medicare Plan Finder now lets you see if your doctor or hospital is included in a Medicare Advantage plan’s network before selecting a plan. The 2026 plan finder features more information about Medicare Advantage plans’ supplemental benefits—extra coverage options such as dental, hearing, and vision services not available in Original Medicare.

What to Have Ready Before Using Plan Finder

• Your Medicare number (optional but helpful)
• Every prescription you take, including dose and quantity per fill
• The pharmacy you use, by name and location
• Names of your doctors and specialists
• Your ZIP code and county

The tool calculates your estimated annual costs for each available plan, helping you identify true value beyond just advertised premiums. Plans rated 4 or 5 stars have demonstrated better quality of care and member satisfaction.