Medicare Annual Enrollment Period 2026: What to Do Before October 15

October is when many people on Medicare first notice a thick envelope from their plan—or realize they never opened last year’s Annual Notice of Change. The Medicare Annual Enrollment Period (AEP), also called Open Enrollment, runs from October 15 through December 7, 2026. Changes you make during that window generally take effect on January 1, 2027.

This guide is educational only. It is not personalized insurance, medical, tax, or legal advice. Plan rules, premiums, and formularies change; always confirm current details on Medicare.gov, with your plan, Social Security, or a licensed counselor before you enroll or switch.

What Is the Medicare Annual Enrollment Period?

AEP is the yearly window when most people with Medicare can review and change their coverage for the coming calendar year. During October 15 – December 7, 2026, you can typically:

• Switch from one Medicare Advantage (Part C) plan to another
• Switch between Original Medicare and a Medicare Advantage plan
• Join, drop, or switch a Medicare Part D prescription drug plan
• Add or drop Medicare Advantage coverage connected to Part D (as your situation allows)

Outside AEP, other special enrollment periods may apply (for example, after certain plan exits or moves), but for most households the fall window is the main chance to fix a mismatch before the new year. Missing December 7 can mean waiting until the next AEP—or relying on a narrower special period if you qualify.

Prep Checklist Before October 15

You do not need to wait until Open Enrollment day to get organized. A short prep list before October 15 makes Plan Finder comparisons faster and reduces last-minute mistakes.

1. Find your Annual Notice of Change (ANOC). Plans should send the ANOC so you can see what changes for the next year—premiums, deductibles, cost-sharing, network, and formulary highlights. CMS guidance expects the ANOC around late September (by about September 30). If yours is missing by early October, call your plan or check Medicare.gov, and keep notes of whom you spoke with.
2. List every prescription you take. Include drug name, dose, how often you fill, and preferred pharmacy. Part D and many Medicare Advantage plans change formularies; a drug that was Tier 2 this year may move tiers—or require prior authorization—next year.
3. List your doctors, clinics, and hospitals. For Medicare Advantage and some other arrangements, network status matters. Confirm whether your primary care doctor, specialists, and preferred facilities stay in-network for 2027.
4. Note what you spent out-of-pocket this year. Deductibles, copays, coinsurance, and pharmacy costs help you judge whether a lower premium with higher cost-sharing would have hurt—or whether a higher-premium plan with better coverage would have paid for itself.
5. Flag health changes. New diagnoses, upcoming surgeries, new specialists, or expected high-cost drugs all change which plan design fits. Your 2025–2026 experience is useful, but next year’s needs matter more.

Original Medicare vs Medicare Advantage vs Part D (Plain English)

Original Medicare is the federal program’s Part A (hospital) and Part B (medical) coverage. Many people add a separate Part D plan for drugs and, separately, may buy a Medigap (Medicare Supplement) policy to help with cost-sharing—subject to Medigap underwriting and timing rules that are different from AEP. Original Medicare generally lets you see any provider who accepts Medicare nationwide, with standard deductibles and coinsurance.

Medicare Advantage (Part C) is coverage offered by private insurers approved by Medicare. These plans bundle Part A and Part B benefits and often include Part D plus extras (dental, vision, hearing, fitness). They usually use networks, prior authorization, and plan-specific cost-sharing. During AEP you can switch Advantage plans or move back to Original Medicare (and then arrange Part D/Medigap as needed).

Part D is prescription drug coverage. If you have Original Medicare, you typically pick a standalone Part D plan. Many Medicare Advantage plans include Part D. During AEP you can add, drop, or switch Part D coverage according to the rules that apply to your path.

There is no single “best” type for everyone. The right fit depends on your doctors, drugs, travel habits, budget for premiums versus out-of-pocket costs, and whether you value nationwide Original Medicare access or an Advantage plan’s extras and care coordination.

How to Compare Plans on Medicare.gov (and Free SHIP Help)

The official tool is Medicare’s Plan Finder: medicare.gov/plan-compare. Enter your ZIP code, your list of drugs and pharmacies, and (when relevant) your doctors. Review estimated total costs—not only the monthly premium—along with star ratings, deductibles, and coverage details for 2027.

If online tools feel overwhelming, use free counseling. State Health Insurance Assistance Programs (SHIP) offer unbiased local help. Start at shiphelp.org, or call 1-800-MEDICARE (1-800-633-4227). Bring your ANOC, drug list, and doctor list to the appointment.

2026 Part B Premium and Deductible (CMS)

According to CMS, the standard Medicare Part B premium for 2026 is $202.90 per month, and the Part B annual deductible is $283 for 2026. These figures apply to most beneficiaries who pay the standard amount; your Social Security benefit statement or Medicare account will show what you are billed.

Part B premiums are separate from Medicare Advantage plan premiums and Part D premiums. When you compare Advantage or Part D options, remember you generally still owe Part B (and any income-related adjustment) unless a rare exception applies.

Always verify the latest official numbers on Medicare.gov costs or CMS announcements, because blogs and ads sometimes recycle outdated years.

Brief Note on IRMAA (Higher Income)

If your modified adjusted gross income (MAGI) from your tax return two years prior is above the IRMAA thresholds, you pay an Income-Related Monthly Adjustment Amount on top of the standard Part B premium—and possibly on Part D as well. For 2026 premiums, Social Security generally looks at 2024 income. Higher brackets can raise Part B well above the standard $202.90 (in the highest brackets, Part B can approach roughly $690 per month—confirm the exact bracket table on Medicare.gov or SSA before you budget).

If your income dropped due to a qualifying life-changing event (retirement, marriage, divorce, loss of income, and other SSA-listed events), you may request a reduction using form SSA-44 rather than waiting for the usual two-year lookback to catch up. Details and eligibility are on Social Security’s site; this is not tax advice—talk to SSA or a qualified professional about your facts.

Practical AEP Checklist

• □ Locate ANOC; call plan or Medicare.gov if missing by early October
• □ Write a current medication and pharmacy list
• □ Confirm 2027 network status for key doctors and facilities
• □ Estimate last year’s out-of-pocket medical and drug spending
• □ Run Medicare.gov Plan Finder with your real drugs and ZIP
• □ Compare total estimated annual cost, not premium alone
• □ Check 2027 formulary tiers, prior auth, and preferred pharmacies
• □ Note Part B standard premium $202.90 and deductible $283 (CMS 2026); check IRMAA if income is high
• □ Call SHIP or 1-800-MEDICARE if you want a second set of eyes
• □ Complete any switch or enrollment by December 7, 2026
• □ Save confirmation numbers and screenshots of what you submitted

Common Mistakes to Avoid

• Ignoring the ANOC. “My plan was fine last year” is not a 2027 guarantee.
• Shopping on premium only. A cheap monthly rate with a harsh formulary or narrow network can cost more when you need care.
• Missing December 7. Late changes may not take effect January 1.
• Skipping formulary and network checks for 2027. Drug tiers and doctor lists are where surprises hide.
• Assuming Medigap rules match AEP. Supplement policies follow different timing and underwriting rules—research those separately if you leave Advantage for Original Medicare.

FAQ

When is Medicare Open Enrollment 2026?
October 15 through December 7, 2026. Changes made during AEP generally start January 1, 2027.

What if I never got my ANOC?
Contact your current plan and check Medicare.gov. Do not wait until mid-November; you need the change notice to compare accurately.

Can I switch from Medicare Advantage back to Original Medicare during AEP?
Yes, AEP is designed to allow that path (and the reverse), subject to how you then arrange Part D and any Medigap coverage. Confirm steps on Medicare.gov or with SHIP so you do not have a coverage gap for drugs.

Where should I compare plans?
Use medicare.gov/plan-compare. For free local counseling, use shiphelp.org or 1-800-MEDICARE.

What is the 2026 Part B standard premium?
CMS set the standard Part B premium at $202.90 per month for 2026, with a $283 Part B deductible. Higher-income beneficiaries may owe IRMAA; check Medicare.gov and your SSA notice.

Next Step

Pull your ANOC this week, update your drug and doctor lists, then run Plan Finder before you feel rushed. A calm review in early October beats a December scramble. For official tools and costs, start at Medicare.gov—and call SHIP or 1-800-MEDICARE if you want help interpreting the options that appear for your ZIP code.

Dollar Lane publishes educational U.S. personal finance and insurance explainers. Nothing here is an offer of coverage or a recommendation of any specific insurer or plan.