The Basics

Medigap (Medicare Supplement) Plans Explained

Medigap is private insurance that works with Original Medicare. It helps pay costs Medicare doesn't cover—like deductibles (the amount you pay before Medicare kicks in), coinsurance (your percentage share of the bill), and copays (fixed amounts per visit). Every insurance company offers the same coverage for the same plan letter.

What Is Medigap?

Medigap is private health insurance you buy from insurance companies to help pay costs that Original Medicare doesn't cover. It works only with Original Medicare (Medicare Part A and Part B). It does not work with Medicare Advantage.

When you have both Original Medicare and a Medigap policy, Medicare pays first. Then Medigap pays its share of what's left. This reduces what comes out of your pocket for:

Medigap does not cover prescription drugs, long-term care, dental, vision, or hearing aids. These are covered by other programs.

Medigap vs. Medicare Advantage: A Critical Difference

Medigap and Medicare Advantage are two very different ways to get extra coverage:

Medigap

  • Works with: Original Medicare only
  • Pays: Your out-of-pocket costs (deductibles, coinsurance, copays)
  • Network: Accepted anywhere Medicare is accepted
  • Enrollment: Separate from Medicare

Medicare Advantage (Part C)

  • Replaces: Original Medicare entirely
  • Includes: Part A, Part B, and usually Part D (drugs)
  • Network: Limited to plan's network providers
  • Enrollment: Replaces Original Medicare

You cannot have both Medigap and Medicare Advantage at the same time. If you want Medigap, you must be in Original Medicare. You cannot be in a Medicare Advantage plan.

Standardized Medigap Plans: A–N

Medigap plans are named by letter. Plan G from any insurance company covers the same benefits as Plan G from any other company. The only differences are the price and how good the customer service is.

The standardized plans are: A, B, C, D, F, G, K, L, M, and N. Each offers a different combination of benefits at different price levels.

Plans C and F: Closed to New Beneficiaries

If you first became eligible for Medicare on January 1, 2020 or later, you cannot enroll in Plans C or F. These plans closed to new people.

If you became eligible for Medicare before January 1, 2020, you can still enroll in or keep Plan C or F. But if you switch to a different plan, you generally cannot switch back to it later.

Massachusetts, Minnesota, and Wisconsin

Massachusetts, Minnesota, and Wisconsin have different rules. Medigap plans in these states may have different names and benefits. Call your state's insurance office or your insurance company to learn about plans where you live.

Medigap Standardized Benefits Comparison

Use this chart to see what each plan covers. A checkmark or percentage means the plan pays that cost. A dash (—) means it doesn't. Plans K and L cover less of each bill but have a yearly cap on what you pay out of your pocket. That makes them cheaper.

Medigap Benefit Plan A Plan B Plan C Plan D Plan F Plan G Plan K Plan L Plan M Plan N
Part A Coinsurance & Hospital Costs (days 61–90, days 91–150 lifetime reserve) Yes Yes Yes Yes Yes Yes 50% 75% Yes Yes
Part A Hospice Coinsurance or Copayment Yes Yes Yes Yes Yes Yes 50% 75% Yes Yes
Part B Coinsurance or Copayment Yes Yes Yes Yes Yes 50% 75% Yes Copay
Part B Excess Charges (charges above Medicare's approved amount) Yes Yes
Part A Deductible Yes Yes Yes Yes Yes 50% 75% Yes Yes
Part B Deductible Yes Yes
Skilled Nursing Facility (SNF) Coinsurance (days 21–100) Yes Yes Yes Yes Yes Yes 50% 75% Yes Yes
Blood (first 3 pints per year) Yes Yes Yes Yes Yes Yes 50% 75% Yes Yes
Foreign Travel Emergency (up to plan limits) Yes Yes Yes Yes Yes Yes
Out-of-Pocket Limit (annual maximum you pay) Yes (annual limit) Yes (annual limit)
Dollar amounts change every year. The yearly limits for Plans K and L change. So do deductible and coinsurance amounts. Check Medicare.gov for this year's numbers.

Understanding the Medigap Open Enrollment Period

The Medigap Open Enrollment Period is a six-month window. During this time, insurance companies must sell you Medigap. They cannot say no or charge you more because of your health. This is your best chance to get Medigap without any medical questions.

When Does It Start?

Your six-month period starts on the first day of the month when you turn 65 and enroll in Medicare Part B.

Example: If you turn 65 on March 15 and enroll in Part B, your period starts March 1 and ends August 31.

What Does It Mean?

During this period:

After the Open Enrollment Period Ends

If you apply for Medigap after this window ends, the insurance company may:

There are some exceptions (like if you leave a Medicare Advantage plan, you might get a second chance), but your first Open Enrollment Period is your best opportunity to enroll without any problems.

Choosing a Medigap Plan

All Plans With the Same Letter Are Identical

When you compare Medigap plans, remember that all Plan G policies cover the same things, all Plan N policies cover the same things, and so on. The insurance company does not matter for benefits—it only matters for price and how good their customer service is.

If you want Plan G, look for the cheapest Plan G with good customer reviews. There's no point in paying more for the same coverage.

Price Varies by Insurer, Age, and Location

Benefits are the same everywhere, but prices are not. The same Plan G costs different amounts at different companies. Insurers also charge in different ways:

Prices also vary by state and neighborhood. The key point: get quotes from several companies for the same plan letter.

Use Medicare's Medigap Finder

Medicare has a free online tool to compare Medigap plans and prices in your area. Go to Medicare's Medigap page to search for plans, read details, and see ratings.

When to Enroll and When You Can Switch

The best time to enroll in Medigap is during your Open Enrollment Period (the six-month window when you turn 65 and enroll in Part B). This way you won't have medical underwriting (health checks).

If you apply after that window, the company may ask health questions. You might pay more or even be turned down. In some cases, you may get a second chance (like if you leave a Medicare Advantage plan), but this is rare.

You can switch from one Medigap plan to another. But if you switch to a plan that covers less, you usually cannot go back to the plan you left. This is called the step-down rule. You can switch to a plan with more coverage. Ask your state insurance office about the current rules.

Getting Help With Medigap

Medigap is confusing. Free help is out there:

Getting Help Paying

Overview of assistance programs and counseling services for Medicare costs, including Medigap guidance.

SHIP Directory

Find your state's SHIP (State Health Insurance Assistance Program) for free, personalized Medigap counseling.

State Insurance Departments

Contact your state's insurance commissioner or department for Medigap-specific complaints, questions, and regulations.

Related Topics

To understand Medigap better, read about the programs it works with:

Check the facts before you decide. This page explains how Medigap works and what each plan covers. Your state may have different rules. Your situation may be different. Always check the details on Medicare.gov, your state insurance website, and your insurance company's paperwork before you enroll. This page is for learning only. It is not medical, legal, or financial advice. It does not tell you which plan to pick.
Want free, unbiased help with this? A SHIP counselor gives free, one-on-one Medicare guidance and sells nothing. For Medicaid, contact your state agency. You can also call 1-800-MEDICARE (1-800-633-4227).