What to Know About Medicare Open Enrollment to Make Confident Choices

Peter Richardson is a vice president of Planning Philosophy and Thought Leadership at Northwestern Mutual.

Medicare open enrollment can feel overwhelming, whether you just enrolled in Medicare or you help a parent or spouse who did. Think of it as an annual checkup for your coverage. Few retirement decisions give you a fresh start every year, and this one does.

Many people let that opportunity pass. KFF found that nearly seven in 10 Medicare beneficiaries did not compare plans during the 2021 open enrollment period. Plans change premiums, drug lists, and provider networks from one year to the next, so keeping a plan without a review still counts as a decision.

This article explains what to review, how to compare options, and what happens if you don’t make any changes. It also connects Medicare to the rest of your financial plan, because healthcare costs shape your retirement income, your taxes, and your exposure to expenses Medicare doesn’t pay.

What is Medicare open enrollment, and when does it happen?

Open enrollment gives anyone already enrolled in Medicare a chance to review and change coverage. The period runs from October 15 through December 7 each year, and changes take effect January 1 of the following year.

Other Medicare enrollment windows serve different purposes. Your initial enrollment period lasts seven months, starting three months before the month you turn 65 and ending three months after it. The general enrollment period, January 1 through March 31, lets people who missed their initial window sign up, but a late enrollment penalty may apply. If you already have a Medicare Advantage plan, the Medicare Advantage Open Enrollment Period, also January 1 through March 31, lets you switch or drop your plan.

The October 15 to December 7 window applies to changing coverage you already have, not to signing up for the first time. Medicare open enrollment also differs from open enrollment for your workplace benefits, which most employers hold for a few weeks between October and December.

Who can make changes during Medicare open enrollment?

Anyone with Medicare can make changes during open enrollment. You can switch between Original Medicare and Medicare Advantage; move from one Medicare Advantage plan to another; or join, switch, or drop a Part D prescription drug plan.

Medigap supplemental coverage follows separate rules, and those rules carry real consequences. Federal law allows Medigap insurers to use medical underwriting outside guaranteed issue periods, which means an insurer can deny a policy or charge more based on your health. Some states offer broader protections, so check your state’s rules before you switch.

Timing is especially important if you’re considering Medicare Advantage. KFF notes that a person with a pre-existing condition who leaves Medicare Advantage for Original Medicare after the initial 12-month trial period may not qualify for a Medigap policy. A good plan keeps your future options open, and a move into Medicare Advantage can close one that proves hard to reopen.

In 2026, more than half (55 percent) of eligible Medicare beneficiaries have Medicare Advantage coverage. Those plans can change costs, benefits, provider networks, and drug coverage each year, so an annual review matters even if you expect to keep your current plan.

What to review during Medicare open enrollment

Use open enrollment to confirm that your coverage still fits your life. Here are four areas to review each year.

Review your current coverage

Start with your plan’s Annual Notice of Change, which lists updates to benefits and costs for the coming year. Then ask whether your Part A (hospital insurance) and Part B (medical insurance) coverage or your Medicare Advantage plan still meets your needs.

Review your prescriptions

Check whether your Part D plan still covers your current medications and whether their tiers or costs have changed. A drug that cost little last year could cost more this year or drop off the plan’s formulary altogether, so give this step extra attention if your prescriptions have changed. Two limits also change for 2027. The most you can pay out of pocket for covered Part D drugs rises to $2,400, up from $2,100 in 2026, and no drug plan may charge a deductible above $700, up from $615. The cap applies to out-of-pocket spending on covered drugs, so compare monthly premiums separately.

Review your providers and pharmacies

Confirm that your preferred doctors, hospitals, and pharmacies remain in your plan’s network. Networks change from year to year, and a doctor in network this year may leave next year. Medicare Advantage enrollees should also confirm coverage for specialists and preferred facilities.

Review your benefits and costs

Compare premiums, deductibles, copays, coinsurance, and out-of-pocket maximums. Estimate what you could pay over the full year, not just the monthly premium. Also check whether the plan includes dental, vision, hearing, and wellness benefits and whether any of those benefits will change.

How to compare your Medicare options

After you review your current coverage, compare your options. For 2027, the average Medicare beneficiary can choose from 35 Medicare Advantage plans, down from 39 in 2026. The Medicare Plan Finder lets you compare plans side by side; add your medications and pharmacies to see personalized cost estimates. You can also call 1-800-MEDICARE or contact your State Health Insurance Assistance Program (SHIP) for free, unbiased counseling from trained counselors who don’t sell insurance.

Stick with official government tools and SHIP counselors, neither of which sells Medicare plans. Take your time, compare carefully, and resist pressure from anyone urging a specific plan or insurer.

What happens if you don’t change your Medicare plan during open enrollment?

If you don’t make any changes, your current Medicare coverage generally continues into the next year. Costs, benefits, and the drug formulary may still change, and those changes can affect whether the plan fits your needs and budget.

How Medicare connects to the rest of your financial plan

Northwestern Mutual’s approach to planning moves through four phases: building a foundation, strategic planning, optimizing retirement, and wealth transfer. Each phase follows the same principle: Protect what matters first, and then grow. Medicare decisions belong to the optimizing retirement phase, yet they reach into every other part of a plan. Four connections deserve attention while coverage sits top of mind.

Treat healthcare as a core retirement expense

Fidelity estimates that a 65-year-old retiring in 2026 can expect to spend an average of $185,500 on healthcare and medical expenses throughout retirement. The estimate assumes Original Medicare with Part D coverage and excludes long-term care, and Part B and Part D premiums account for 45% of the total. Build Medicare premiums and expected out-of-pocket costs into your retirement income plan as recurring expenses rather than leaving them to chance. Essential, recurring costs pair best with reliable sources of income.

Know that income can raise your premiums

Higher-income beneficiaries pay an income-related monthly adjustment amount, or IRMAA, on top of standard Part B and Part D premiums. Social Security bases IRMAA on your federal tax return from two years earlier; 2026 surcharges, for example, reflect 2024 tax returns. That lag turns IRMAA into a tax-planning question as much as a healthcare question, because a large Roth conversion, capital gain, or retirement account withdrawal can raise premiums two years later. After a life-changing event that reduces income, such as the death of a spouse or a loss of income, you can ask Social Security to lower your IRMAA. Learn more about how IRMAA works.

Plan for what Medicare doesn’t cover

Medicare and Medigap don’t pay for most long-term care, the help with everyday tasks such as bathing and dressing that many people eventually need at home or in a facility. Northwestern Mutual’s 2026 Planning & Progress Study found that 54% of Americans have not planned financially for their own potential long-term care needs, even though 73% would prefer to receive care at home. Long-term care is where retirement and risk planning come together. Use open enrollment to ask how you would pay for care (through savings, insurance, or both) and what an extended care event would mean for a spouse and for the legacy you hope to leave.

Approaching 65? Plan the transition early

People in their late 50s and early 60s can make choices now that shape Medicare costs later. Retiring earlier requires a plan to pay for health coverage until then, and that cost belongs in a retirement plan from the start. Income decisions in the years just before enrollment matter, too, because IRMAA looks back two years.

An annual review can help you avoid surprises and choose coverage that supports both your care and your financial priorities. Before you compare options, gather your plan notice, medication list, provider information, and expected healthcare needs. Then make any changes by December 7.

Your Northwestern Mutual financial advisor can help you plan for Medicare costs alongside your income, savings, and long-term goals. Advisors don’t select or sell Medicare coverage, but a financial advisor can help with retirement planning, including how medical costs impact your overall plan. A good first step: Ask your advisor to build premiums and expected out-of-pocket costs into your retirement income plan and to check the IRMAA effect of any large withdrawal or Roth conversion before you make it.

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Frequently Asked Questions

When is Medicare open enrollment?

Medicare open enrollment runs from October 15 through December 7 each year, and changes generally take effect on January 1. This is your chance to revisit existing coverage; it is separate from the periods for first enrolling in Medicare.

What changes can I make during Medicare open enrollment?

If you already have Medicare, you can use open enrollment to switch between Original Medicare and Medicare Advantage; move to a different Medicare Advantage plan; or join, switch, or drop a Part D prescription drug plan. Medigap policies follow separate eligibility and underwriting rules, so review those requirements before dropping supplemental coverage.

What should I review during Medicare open enrollment?

Use your Annual Notice of Change as a starting point, and then verify medications, provider networks, pharmacies, benefits, and total costs. Also consider any expected procedures, new diagnoses, or prescription changes that could affect how you use coverage next year.

What happens if I do nothing during Medicare open enrollment?

Your coverage generally renews, but the terms may not stay the same. Read your Annual Notice of Change so you know whether premiums, cost sharing, benefits, provider access, or drug coverage will be different next year.

How do I compare Medicare plans during open enrollment?

Start with the Medicare Plan Finder on medicare.gov, where you can add your medications and pharmacies for personalized estimates. If you need more help, call 1-800-MEDICARE or contact a State Health Insurance Assistance Program for free, unbiased counseling.

Can I switch from Medicare Advantage back to original Medicare during open enrollment?

Yes, during Medicare open enrollment you can switch from a Medicare Advantage plan back to Original Medicare. You can also join a Part D prescription drug plan at the same time, since Original Medicare doesn’t include prescription drug coverage. If you want Medigap supplemental coverage, keep in mind that Medigap has different enrollment rules and may require medical underwriting depending on your situation.

Should I talk to my financial advisor about my Medicare costs?

Your financial advisor can’t choose or sell a Medicare plan for you, but they can help estimate how premiums, cost sharing, and other healthcare expenses affect your retirement cash flow. That broader view can help if your coverage decision changes your budget or savings strategy.

Can my income affect what I pay for Medicare?

Yes. If your modified adjusted gross income exceeds certain thresholds, you pay a surcharge called IRMAA on top of your Part B and Part D premiums. Social Security generally uses your tax return from two years earlier, so plan large withdrawals, Roth conversions, and asset sales with future Medicare premiums in mind.