Last year, about 2.9 million Medicare Advantage members got a letter saying their plan was ending. Those letters are going out again now.

If your Medicare Advantage plan ends on December 31, the plan has to mail you a letter by early October. That letter gives you a limited-time right to buy a Medigap policy without your health being held against you. The deadlines that matter most fall between December 31 and early March, and they don't match Medicare's usual fall enrollment dates.

Plan endings used to be rare. From 2018 through 2024, just over 1% of Medicare Advantage members lost their plan each year. Going into 2026, it was 10%.

Source: Meiselbach et al., Journal of the American Medical Association, February 2026

At a Glance: The Quick Facts

Key rule: The Medigap right only works if you go back to Original Medicare. Joining another Medicare Advantage plan likely ends it.

Check This First: Which Letter Did You Get?

Insurance companies mail several kinds of letters in the fall. Only one of them gives you the rights in this guide.

• This guide is for you if your letter says your plan is ending, won't be offered next year, or won't be offered in your county.
• This guide doesn't apply if you got an Annual Notice of Change saying the company is moving you into another one of its plans. Your coverage continues, and the Medigap right doesn't come with it. You can still compare plans from October 15 to December 7.

In plain English: If you can't tell which letter you have, call the number on it and ask, "Is my plan ending, or am I being moved to another plan?"

Your Two Options When Your Plan Ends

There are two ways to get your Medicare coverage.

• Medicare Advantage is an all-in-one plan from a private insurance company. It covers your hospital and medical care, and most plans include drug coverage. You can choose a different Medicare Advantage plan for next year.
• Original Medicare plus Medigap is the other path. Original Medicare is the federal program: Part A covers hospital care, and Part B covers doctor visits and other medical care. A Medigap policy, also called Medicare Supplement insurance, pays some or all of what Original Medicare leaves to you, like deductibles and the 20% of the bill you'd usually owe. Medigap doesn't cover prescriptions, so most people add a separate drug plan.

Both are reasonable choices, but your letter matters most if you're considering the second one.

What Guaranteed Issue Means

In most states, a Medigap company can normally review your health history and turn you down. Your letter changes that for a limited time. While your guaranteed issue right lasts, a company selling the plans listed below in your state:

• must sell you a policy
• can't charge you more because of your health
• can't make you wait for coverage of a condition you already have

The application may still ask health questions. The company just can't use your answers to say no or raise your price. Your premium can still depend on your age, where you live, and which company you choose.

This right only applies if you go back to Original Medicare. If you pass on it now, you may not get another chance to buy Medigap without a health review.

Your Deadlines If Your Plan Ends December 31, 2026

Two calendars run at the same time. One is for Medigap. The other is Medicare's calendar for choosing a drug plan or a new Medicare Advantage plan. They end on different days.

1. The day your letter arrives: Your Medigap right starts. You can apply for Medigap now and ask for it to start January 1.
2. October 15 to December 7: Medicare's open enrollment. Any drug plan or Medicare Advantage plan you choose starts January 1.
3. December 8, 2026 to February 28, 2027: A Special Enrollment Period for people whose plan is ending. It's another chance to choose a drug plan or a Medicare Advantage plan.
4. December 31, 2026: Your plan's last day. If your new coverage is chosen by now, you'll have no gap.
5. February 28, 2027: Last day to choose a drug plan with the Special Enrollment Period. A plan chosen in February starts March 1.
6. March 4, 2027: Your Medigap right ends, 63 days after your coverage stops. After this, companies can review your health and say no.

Why December 31 matters: If you haven't chosen new coverage when your plan ends, January starts with Original Medicare alone. You'd have no Medigap to help with the 20% you owe for most care, and no drug plan for your prescriptions.

For most people, February 28 is the date that counts. Medigap doesn't cover prescriptions, so you'll also need a separate drug plan. If you wait until March to buy Medigap, the window to add a drug plan will already be closed. You could go most of the year without drug coverage and pay a late penalty for as long as you have Medicare drug coverage.

If your plan ends on a different date, including partway through the year, the Medigap rule works the same way. Your right starts when the letter arrives and ends 63 days after your coverage stops. Medicare's dates for choosing a new plan will be different, and your letter should list them.

Which Medigap Plans You Can Get

Medigap plans are differentiated by letters. A Plan G from one company covers the same things as a Plan G from any other company, so the main difference is in carrier and price. The plans you're guaranteed depend on when you first qualified for Medicare, including if you qualified because of a disability.

If you qualified before 2020, Plan F covers everything Plan G covers, plus the Part B deductible. Plan G isn't on your guaranteed list. You can still apply for it, but the company may review your health and turn you down.

Companies only have to sell you plans they already offer in your state. Every Medigap company must offer Plan A. A high-deductible plan has a lower monthly premium, but you pay more of your costs (up to $2,950 in 2026) before it starts paying.

What to Do This Week

1. Keep the letter and the envelope it came in. A Medigap company may ask for a copy with your application. The postmark shows when it was mailed.
2. Choose your direction. You can pick another Medicare Advantage plan, or go back to Original Medicare with a Medigap policy and a drug plan. This letter is the rare time the second option doesn't depend on your health.
3. If you want Medigap, apply before December 31. Ask for your policy to start January 1, the day after your plan ends.
4. Choose a drug plan by December 31. Any drug plan you choose by then starts January 1.

Free Help With Your Letter

A Licensed Medicare Advisor can look at your letter with you, confirm your dates, and compare Medigap, drug plans, and Medicare Advantage plans side by side. Call 866-764-3312 (TTY: 711), 7 AM to 7 PM CST. No cost. No obligation.

For free, unbiased counseling from your state, find your State Health Insurance Assistance Program (SHIP) at shiphelp.org, or call Medicare at 1-800-633-4227 (TTY 1-877-486-2048).

Situations With Different Rules

Some people have different rules: people with Medicaid, people under 65, people who live in Connecticut, New York, Massachusetts, Minnesota, or Wisconsin, people who joined Medicare Advantage less than a year ago, and anyone whose plan sent a notice about a network change. More details and other frequently asked questions can be seen below.

Disclaimer: This article is for informational purposes only and isn't legal advice. Medicare rules can change, and some rules vary by state.

Sources: Social Security Act §1882(s)(3) and (z), 42 U.S.C. §1395ss; NAIC Medicare Supplement Insurance Minimum Standards Model Regulation (Model 651, Fall 2025), §§9.2 and 12; CMS, Choosing a Medigap Policy (Publication 02110, March 2026); CMS, Medicare Advantage and Part D Enrollment and Disenrollment Guidance (CY 2027), §30.6.10; 42 CFR Parts 422 and 423; Meiselbach et al., JAMA, February 2026.

Last Updated: September 2026