Yes, you can switch from Medicare Advantage to a Medigap (Medicare Supplement) plan, but timing and your health history matter

You can move from a Medicare Advantage plan to a Medigap policy (also called Medicare Supplement insurance) at certain times during the year. The easiest time to switch is during the Annual Enrollment Period, which runs October 15 to December 7 each year — you can change plans without any health questions asked. Outside that window, switching is harder because insurance companies can deny you or charge more based on your health conditions, a practice called medical underwriting.

The key difference: Medicare Advantage is an all-in-one plan run by a private insurance company that covers hospital, doctor, and prescription drug costs. Medigap is a supplement that works alongside Original Medicare (the government plan) and covers costs that Medicare itself does not pay — copays, coinsurance, and deductibles. The switch means moving away from the Advantage plan's network restrictions and toward Original Medicare's broader provider choice, but it also means paying both a Medicare premium and a Medigap premium.

Key Takeaways

  • You can switch during the Annual Enrollment Period (October 15 to December 7) without health questions, or during your Initial Enrollment Period if you are newly may be able to access for Medicare.
  • Outside open enrollment, insurance companies can refuse to sell you a Medigap plan or charge higher premiums based on your health history.
  • You will pay both a Medicare Part B premium and a Medigap premium, which together may cost more or less than your current Advantage plan depending on the plan you choose.
  • Your prescription drug coverage changes when you switch — Medigap does not include drug coverage, so you must enroll in a separate Part D plan.
  • You have a may provide issue right (the right to buy without health questions) if you lose your Advantage plan involuntarily or if your plan stops offering your current coverage area.

When you can switch without health questions

The Annual Enrollment Period is the main window: October 15 through December 7 each year. During this time, any insurance company must sell you any Medigap plan they offer, regardless of your age or health conditions. Your coverage starts January 1 of the following year. You do not need to wait until your Advantage plan's renewal date — you can switch mid-year during this period.

If you are newly may be able to access for Medicare (you just turned 65 or became may be able to access due to disability), you have a six-month Initial Enrollment Period to buy a Medigap plan without health questions. This period starts the month you turn 65 or become may be able to access. After those six months end, you lose this protection and insurers can deny you or charge more.

You also have a may provide issue right if your Medicare Advantage plan stops serving your area, if your plan is discontinued entirely, or if you lose coverage involuntarily (for example, if you move out of the plan's service area). In these cases, you can buy a Medigap plan within 63 days of losing your Advantage coverage without health questions. Keep documentation of why your plan ended — you may need to show it to the insurance company.

What happens if you switch outside open enrollment

Outside the Annual Enrollment Period and Initial Enrollment Period, insurance companies can ask health questions and use your answers to decide whether to sell you a plan and how much to charge. This is called medical underwriting. They may deny your process entirely, or they may approve you but at a higher premium than someone your age with no health conditions would pay.

Some states have laws that limit how much insurers can charge based on health, but federal law does not require this protection. The amount you pay can vary significantly depending on your state and the insurance company. Before you explore outside open enrollment, contact the insurance company directly and ask whether they will underwrite your process — do not assume they will.

A few states offer Medigap plans C and F with limited underwriting protections for people who miss their Initial Enrollment Period, but these are exceptions. Your best protection is to switch during the Annual Enrollment Period or within 63 days of losing your Advantage plan involuntarily.

How your prescription drug coverage changes

Medicare Advantage plans include prescription drug coverage (Part D) as part of the plan. When you switch to Medigap, that coverage ends. You must enroll in a separate Part D prescription drug plan within 63 days of dropping your Advantage coverage, or you may face a permanent penalty on your Part D premiums.

The 63-day window is important: if you wait longer than 63 days to enroll in Part D, Medicare adds a penalty of about 1% of the national average Part D premium for each month you were without coverage. This penalty stays with you for life. You can enroll in Part D during the Annual Enrollment Period or during a Special Enrollment Period if you lose coverage involuntarily.

Review the Part D plans available in your area before you switch. Your current medications may be cheaper or more expensive under different plans, and formularies (the list of covered drugs) change each year. Use the Medicare Plan Finder tool on Medicare.gov to compare costs for your specific prescriptions.

Comparing costs: Advantage versus Medigap

The total cost of switching depends on the specific plans you are comparing. A Medicare Advantage plan typically has a lower or zero monthly premium but higher out-of-pocket costs when you use care (copays, coinsurance, deductibles). A Medigap plan has a higher monthly premium but lower or zero out-of-pocket costs at the doctor or hospital.

You will pay three separate premiums with Medigap: your Medicare Part B premium (currently $164.90 per month for most people in 2024, though this varies by income), your Medigap premium (which varies by plan letter, age, and state — typically $100 to $300+ per month), and your Part D prescription drug premium (typically $10 to $100+ per month). Add these together and compare to what you currently pay for your Advantage plan.

Medigap plans are labeled A through N, and each letter covers a different set of costs. Plan G and Plan N are the most common for new buyers. Plan G covers most of what Original Medicare does not, while Plan N has slightly lower premiums but higher copays at the doctor. Request quotes from multiple insurance companies — the same plan letter can cost very different amounts depending on the company and your state.

Steps to switch during the Annual Enrollment Period

Contact the Medigap insurance company directly during October 15 to December 7 and ask to enroll in the plan you have chosen. You will need your Medicare card and Social Security number. The company will send you an enrollment form and a policy document. Sign and return the form by the important date to may support your coverage starts January 1.

At the same time, enroll in a Part D prescription drug plan through Medicare.gov or by calling 1-800-MEDICARE. You must do this separately from your Medigap enrollment — they are two different transactions with two different companies. Your Part D coverage also starts January 1 if you enroll by December 7.

You do not need to formally cancel your Medicare Advantage plan — it will end automatically on December 31 when your Medigap coverage begins. However, if you want to confirm the cancellation, you can call your Advantage plan's customer service number and ask them to note that you are switching to Original Medicare and Medigap.

What to ask your doctor and insurance company

Before you switch, ask your current doctor whether they accept Original Medicare and the Medigap plan you are considering. Medicare Advantage plans use networks, so your doctor may be in-network for your Advantage plan but out-of-network for Original Medicare. Most doctors accept Original Medicare, but some do not, and Medigap does not restrict you to a network — you can see any doctor who accepts Medicare.

Ask your Medigap insurance company whether they will underwrite your process if you explore outside the Annual Enrollment Period. Ask for a quote in writing. If they say they will underwrite, ask what health conditions they are most likely to deny or charge more for, so you know what to expect.

Ask your current Advantage plan what happens to any unused deductible or out-of-pocket maximum you have already paid this year. Some plans credit unused amounts, but most do not — the money is lost when you switch. This matters if you are switching mid-year and have already paid a significant deductible.

When to seek help or contact Medicare

Call 1-800-MEDICARE if you have questions about your rights to switch, your Initial Enrollment Period, or may provide issue rights. Medicare staff can tell you whether you may have access to for a may provide issue right and can explain the rules in your state. They can also help you understand the difference between Medigap plans and answer questions about Part D enrollment.

Contact your State Health Insurance information Program (SHIP) for free, unbiased counseling about switching. SHIP counselors are trained to compare plans and can help you understand the costs and coverage of different Medigap options. Find your state's SHIP by calling 1-800-MEDICARE or visiting the Eldercare Locator at 1-800-677-1116.

If an insurance company denies your Medigap process or charges you a higher premium and you believe you have a may provide issue right, file a complaint with your state's insurance commissioner. Include documentation of your may provide issue right (such as a letter from your Advantage plan saying it is discontinuing your coverage) and the insurance company's denial letter.

Frequently Asked Questions

Can I switch back to Medicare Advantage after I buy Medigap?

Yes, but only during the Annual Enrollment Period (October 15 to December 7). Outside that window, Medicare Advantage plans can deny you or charge more based on health conditions. If you switch to Medigap and then want to go back to Advantage, plan to do it during open enrollment to avoid underwriting.

What if my Medicare Advantage plan is being discontinued?

You have a may provide issue right to buy any Medigap plan without health questions within 63 days of your plan ending. Contact the insurance company within that window and tell them your Advantage plan is discontinuing. Keep the notice from your plan as proof.

Do I have to switch to Medigap, or can I stay on Original Medicare without a supplement?

You can stay on Original Medicare alone without Medigap, but you will pay copays, coinsurance, and deductibles out of pocket. Medigap is optional. Many people choose it to reduce unpredictable costs, but it is not required.

Will my Medigap premium go up every year?

Yes. Medigap premiums increase over time due to age and inflation. Some companies use community rating (everyone in your state pays the same price regardless of age), while others use age-rated pricing (your premium goes up as you get older). Ask the insurance company which method they use before you enroll.

What if I have a pre-existing condition and miss my Initial Enrollment Period?

You can still explore during the Annual Enrollment Period without health questions. If you explore outside that window, the insurance company can underwrite your process and may deny you or charge more. Some states have limited protections for people with pre-existing conditions, so contact your state's insurance commissioner or SHIP for information about your specific situation.