To switch from Medicare Advantage to Original Medicare, you disenroll from your Advantage plan during one of two annual windows: the Fall Open Enrollment Period from October 15 through December 7, or the Medicare Advantage Open Enrollment Period from January 1 through March 31. Certain life events open a Special Enrollment Period outside those dates. The disenrollment itself is a phone call or a few clicks. The harder part is what you line up before you make it: a Medigap policy to cap your costs and a standalone Part D plan to cover your drugs. Skip either one and you can end up with uncapped medical bills or a Part D late-enrollment penalty that follows you for life.
When You Can Switch
Fall Open Enrollment: October 15 – December 7
This is the broadest window. You can drop your Medicare Advantage plan, return to Original Medicare, join a standalone Part D drug plan, and apply for a Medigap policy. Original Medicare coverage begins January 1.1Medicare. Open Enrollment
Medicare Advantage Open Enrollment: January 1 – March 31
If you’re already in a Medicare Advantage plan, you get one chance during this window to leave it and return to Original Medicare, with the option to add a standalone Part D plan. Original Medicare coverage starts the first day of the month after your request is processed.2Medicare. Understanding Medicare Advantage and Medicare Drug Plan Enrollment Periods It’s a one-time election. Once you use it, you’re locked in until the next window.
Special Enrollment Periods
Certain events open a window outside the regular calendar:
- You move out of your plan’s service area. The window opens when you move and lasts two full months after.
- Medicare terminates your plan’s contract. You can switch starting one month before the contract ends and for two months after. If the plan and Medicare mutually agree to end the contract, the window is two months before through one month after.
- Your plan’s contract isn’t renewed. You can switch between December 8 and the last day of February.
In any of these situations, if you don’t actively join another Medicare Advantage plan before yours ends, Medicare enrolls you in Original Medicare automatically.3Medicare. Special Enrollment Periods
How to Disenroll
You have three ways to leave your Advantage plan:
- Call 1-800-MEDICARE (1-800-633-4227) and tell the representative you want to disenroll. They verify your identity and process the request. A confirmation letter arrives within about a week.4Social Security Administration. Disenrollment from Medicare Advantage (MA) and 1876 Cost Plans
- Contact your Medicare Advantage plan directly by phone or through its website.
- Use the plan comparison tool at Medicare.gov during Fall Open Enrollment.5Medicare. Joining a Plan
Once you disenroll, you’re back in Original Medicare (Part A and Part B). If you’re unsure both parts are active, call Social Security at 1-800-772-1213 to check.
Check Your Medigap Options Before You Switch
This is the step most people skip, and it’s the one that can hurt. Original Medicare has no annual cap on out-of-pocket costs.6Medicare. Costs A Medigap policy (Medicare Supplement Insurance) fills that gap by covering deductibles, copays, and coinsurance. Whether you can actually buy one depends almost entirely on timing.
The Six-Month Guaranteed Window Is Once in a Lifetime
Federal law gives you one six-month Medigap Open Enrollment Period. It starts the first month you’re both 65 or older and enrolled in Part B. During those six months, insurers can’t turn you down, charge more for health problems, or make you wait for pre-existing condition coverage.7Medicare. Get Ready to Buy It doesn’t repeat.
If you used that window when you first enrolled in Medicare and then joined an Advantage plan later, you’ve spent it. Returning to Original Medicare now doesn’t reopen it.
What Underwriting Looks Like Outside That Window
In most states, insurers can medically underwrite Medigap applications outside the guaranteed window. That means reviewing your health history, denying your application, charging higher premiums, or imposing a six-month waiting period for pre-existing conditions. Diabetes with complications, heart disease, and a cancer history are examples of conditions that can lead to outright denial.
A few states are more protective. Connecticut, Massachusetts, and New York require continuous open enrollment, meaning insurers must sell you a Medigap policy at any time without underwriting. Some other states offer narrower protections such as annual birthday-rule windows.
Guaranteed Issue Rights That Can Still Protect You
Federal law preserves guaranteed issue rights in specific situations even after your original window closes:8Medicare. Choosing a Medigap Policy
- Your Medicare Advantage plan leaves your area, is terminated, or makes a significant network change.
- You move out of the plan’s service area.
- Trial right: if you dropped a Medigap policy to try Medicare Advantage for the first time, you have 12 months to return to Original Medicare and get your old Medigap policy back (or a similar one if it’s no longer sold). The same applies if you first joined Medicare Advantage when you turned 65.9Medicare. Learn How Medigap Works
If none of those apply, call Medigap insurers in your area before you disenroll and ask what underwriting would look like for you. Finding out you can’t get a policy after you’ve already left your Advantage plan is difficult to undo.
Line Up Part D at the Same Time
Original Medicare does not include prescription drug coverage. Most Advantage plans do. When you return to Original Medicare, you need a standalone Part D plan, sold by private insurers, each with its own premium, deductible, and formulary.10Medicare. What’s Medicare Drug Coverage (Part D)?
Go 63 or more consecutive days without Part D or other creditable drug coverage and you’ll owe a late enrollment penalty when you eventually sign up. Medicare calculates it as 1% of the national base beneficiary premium ($38.99 in 2026) times the number of full months you went without coverage.11Medicare. 2026 Medicare Costs The penalty is added to your Part D premium permanently, for as long as you have Part D.12Centers for Medicare & Medicaid Services. Creditable Coverage and Late Enrollment Penalty
Two years without coverage would translate to roughly $9.36 added every month, forever. The fix is straightforward: enroll in a Part D plan the same time you disenroll from Medicare Advantage. Your Advantage plan’s drug coverage counts as creditable, so the years you spent in the plan don’t count against you. Keep any creditable coverage notices you’ve received as proof.13Medicare. Notice of Creditable Coverage
What Your Coverage Will Look Like Afterward
Original Medicare lets you see any doctor or hospital nationwide that accepts Medicare, with no referrals and no service-area limits. Part A covers inpatient hospital stays, skilled nursing facility care, and hospice; Part B covers doctor visits, outpatient services, and preventive care.14Medicare. Get Started with Medicare
You lose the extras most Advantage plans bundle in. Routine dental, vision exams, eyeglasses, hearing exams, and hearing aids are not covered by Original Medicare.15Medicare. What’s Not Covered? Standard Medigap policies don’t cover them either.16Medicare. Learn What Medigap Covers If you use those benefits, budget for standalone plans or out-of-pocket costs. You also lose the annual out-of-pocket maximum that Advantage plans are required to include.
2026 Costs Under Original Medicare
- Part A premium: $0 for most people (based on 10 years of Medicare-taxed work). Otherwise $311 or $565 per month depending on work quarters.6Medicare. Costs
- Part A deductible: $1,736 per benefit period for inpatient hospital stays, with no annual limit on the number of benefit periods.
- Part B premium: $202.90 per month at the standard rate; higher-income enrollees pay more.17Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
- Part B deductible: $283 per year.
- Part B coinsurance: generally 20% of the Medicare-approved amount, with no annual cap.
A Medigap policy can cover most or all of this cost-sharing. Monthly premiums vary by age, location, and insurer.18Medicare. Compare Medigap Plan Benefits
A Checklist Before You Disenroll
- Confirm you can get a Medigap policy. Check your guaranteed issue rights, your state’s rules, and, if you’re going to be underwritten, call insurers before you switch.
- Confirm your doctors accept Medicare assignment.
- Choose a standalone Part D plan and verify your medications are on its formulary. Use the plan finder at Medicare.gov.
- Plan for dental, vision, and hearing costs you may lose.
- Run the numbers on a hospitalization or major illness without Medigap. A single inpatient stay costs $1,736 in deductibles before Medicare pays anything, and the 20% Part B coinsurance has no ceiling.
For many people, Original Medicare with a Medigap policy and a Part D plan delivers more flexibility and more predictable costs than an Advantage plan. The switch works well when you can actually get the supplemental coverage you need. If underwriting is likely to block you from Medigap, staying in Medicare Advantage or moving to a different Advantage plan may be the safer call.