Medigap Coverage Explained: What These Plans Actually Pay For (and What They Don’t)

When you have Original Medicare (Part A and Part B), you quickly notice it doesn’t pay 100% of your medical costs. There are deductibles, copayments, and coinsurance that can add up.

That’s where Medigap, also called Medicare Supplement Insurance, comes in. Medigap plans are designed to help pay the “gaps” in Original Medicare — but they don’t all cover the same things, and they don’t cover everything.

This guide walks you through what Medigap plans typically cover, what they never cover, and how to think about which benefits might matter most to you.

What Is a Medigap Plan?

A Medigap plan is an optional insurance policy you can buy from a private company to work with Original Medicare. It helps pay certain costs that Original Medicare doesn’t fully cover, such as:

• Part A and Part B coinsurance
• Some deductibles
• Copayments for hospital and medical visits
• Certain extra benefits like foreign travel emergency care (with some plans)

Key points:

• You must have Medicare Part A and Part B to buy Medigap.
• Medigap only works with Original Medicare, not Medicare Advantage.
• Each Medigap plan is labeled with a letter (A, B, D, G, K, L, M, N, etc.).
• In most states, coverage for each plan letter is standardized. For example, Plan G from one company covers the same types of benefits as Plan G from another company; the difference is usually price and service, not the core benefits.

The Core Question: What Does a Medigap Plan Cover?

In general, most Medigap plans cover all or part of:

1. Medicare Part A coinsurance and hospital costs
2. Medicare Part B coinsurance or copayments
3. Blood (first 3 pints)
4. Part A hospice care coinsurance or copayments
5. Skilled nursing facility care coinsurance (many plans)
6. Part A deductible (many plans)
7. Part B deductible (only some older plans)
8. Part B excess charges (some plans)
9. Limited foreign travel emergency care (some plans)

Not every plan covers all of these, and some cover only a percentage.

Quick Coverage Snapshot: What Most Medigap Plans Help With

Here’s a simplified overview of the main “gaps” in Medicare that Medigap can help cover:

*Exact coverage depends on the plan letter (A, B, D, G, K, L, M, N, etc.) and when you first became eligible for Medicare.

What Every Medigap Plan Covers (at a Minimum)

No matter which Medigap plan letter you choose, every standardized Medigap plan must cover these core benefits:

1. Part A Coinsurance and Hospital Costs

Original Medicare Part A covers inpatient hospital care, but after a certain number of days, coinsurance kicks in.

All Medigap plans cover:

• Part A coinsurance for hospital stays
• Up to an extra 365 days of hospital coverage after your Medicare hospital benefits run out

This is one of the strongest guarantees: every Medigap plan helps protect you from very long, expensive hospital stays.

2. Part B Coinsurance or Copayments

Original Medicare Part B usually pays 80% of approved medical costs after you meet your deductible, leaving you with about 20% coinsurance.

Every Medigap plan helps with:

• Part B coinsurance or copayments, at least partially

Some plans cover this coinsurance fully; others may require a small copayment for office or emergency room visits.

3. First 3 Pints of Blood

Original Medicare does not cover the first 3 pints of blood you may need in a year. All Medigap plans cover these.

After that, Medicare covers additional blood transfusions according to its own rules.

4. Part A Hospice Care Coinsurance or Copayments

Medicare Part A covers hospice care, but there can be small copayments or coinsurance for medications or respite care.

All Medigap plans help pay these hospice-related out-of-pocket costs.

What Many (But Not All) Medigap Plans Cover

Beyond the core benefits, some Medigap plans offer additional protections that can be important depending on your health and budget.

1. Skilled Nursing Facility (SNF) Coinsurance

If you need care in a skilled nursing facility after a hospital stay, Medicare Part A covers it, but after a certain number of days, you owe daily coinsurance.

Several Medigap plans help pay this skilled nursing facility coinsurance. This can be valuable for people worried about rehabilitation or recovery stays after surgery, stroke, or serious illness.

2. Medicare Part A Deductible

The Part A deductible is what you pay when you’re admitted as an inpatient to a hospital before Medicare starts paying its share.

Many Medigap plans cover all or part of this Part A hospital deductible, which can help smooth out the cost of an unexpected hospital admission.

3. Medicare Part B Deductible (Limited to Older Plans)

Some older Medigap plans, such as Plan F and Plan C, pay the Part B annual deductible.

However, people who became newly eligible for Medicare on or after January 1, 2020 generally cannot buy plans that cover the Part B deductible. If you were eligible for Medicare before that date, you may still be able to enroll in one of these plans, depending on availability and underwriting rules.

4. Part B Excess Charges

Some healthcare providers accept Medicare patients but do not accept Medicare “assignment”, meaning they might legally charge you up to a limited amount above the standard Medicare-approved amount. These are called Part B excess charges.

Certain Medigap plans (commonly Plan F and Plan G) cover these excess charges, protecting you from these additional out-of-pocket fees when they occur in your state and situation.

5. Foreign Travel Emergency Care

Original Medicare generally does not cover care outside the United States, with only a few limited exceptions.

Some Medigap plans offer limited foreign travel emergency coverage, typically with:

• A lifetime maximum benefit limit
• A deductible
• Coverage up to a percentage of emergency costs during the first 60 days of a trip

This benefit can be especially important if you travel internationally or spend long periods outside the U.S.

Plans That Share Costs: K and L

A couple of Medigap plans work differently by paying a percentage of many covered costs instead of the full amount:

• Plan K and Plan L pay a set percentage (such as 50% or 75%) of certain Medicare cost-sharing items until you reach an annual out-of-pocket limit. After that, the plan pays 100% of covered services for the rest of the year.

People sometimes consider these plans if they want:

• Lower monthly premiums
• Some protection against very high costs
• A predictable maximum out-of-pocket amount each year

They do, however, leave you with more cost-sharing than some of the more comprehensive plans.

What Medigap Plans Do Not Cover

It’s just as important to understand what Medigap does not cover, so you can avoid surprises and know what other coverage you might need.

In general, Medigap plans do not cover:

• Prescription drugs (outpatient medications)
  • For drug coverage, people typically enroll in a separate Medicare Part D plan.
• Routine dental care, such as cleanings, fillings, or dentures
• Routine vision care (eye exams for glasses, eyeglasses, contact lenses)
• Routine hearing care (hearing exams for hearing aids, hearing aids themselves)
• Long-term care (custodial care in a nursing home or assisted living when you do not need skilled medical care)
• Private-duty nursing in most situations
• Care outside the U.S., except for the limited emergency coverage included in a few Medigap plans
• Non-medically necessary services, such as cosmetic procedures

Also important:

• Medigap does not replace Medicare Part A or Part B. You must remain enrolled in both.
• Medigap does not cover costs when you are enrolled in a Medicare Advantage (Part C) plan. You generally can’t use Medigap with Medicare Advantage.

How Medigap Works with Original Medicare

Understanding how the pieces fit together can make Medigap feel less confusing.

✨ Basic flow when you receive care with Original Medicare + Medigap:

1. You see a provider who accepts Medicare.
2. Medicare pays its share of covered services.
3. Your Medigap plan then pays its share of the remaining costs, based on the plan’s benefits.
4. You pay any remaining deductibles, copayments, or coinsurance that your Medigap plan does not cover.

You continue to pay:

• Your Part B premium to Medicare
• Your Medigap premium to the private insurer
• Your Part D premium if you choose a prescription drug plan

The Different Medigap Plan Letters: Coverage Level Overview

While you don’t need to memorize each plan, it can help to know how the plan letters generally compare:

• Plan A – Basic core benefits only (no extras like SNF coinsurance or deductibles)
• Plan B – Like Plan A, but adds Part A deductible
• Plan D – More coverage, including skilled nursing facility coinsurance and foreign travel emergency, but not Part B deductible or excess charges
• Plan G – Often considered one of the more comprehensive modern plans; covers almost all gaps except the Part B deductible
• Plan K & Plan L – Cost-sharing plans with lower premiums and an out-of-pocket maximum, but you pay a percentage of most costs
• Plan M – Similar to some comprehensive plans but only covers 50% of the Part A deductible
• Plan N – Covers many core gaps; you typically pay small copays for some office and ER visits, and it does not cover Part B excess charges

For people who were Medicare-eligible before January 1, 2020, Plan C and Plan F (which cover the Part B deductible) may still be available in some cases. These are considered very comprehensive.

The “best” plan depends on your:

• Budget for monthly premiums
• Comfort level with paying some out-of-pocket costs
• Health usage patterns (frequent visits vs. rare visits)
• Travel habits (especially if you go abroad)

Practical Ways to Think About Medigap Coverage

When people compare Medigap options, they often focus on how plans handle these key issues:

1. Do I want protection against high hospital and SNF costs?

   • Look at plans that cover Part A deductible and skilled nursing facility coinsurance.

2. How important is it to reduce my regular doctor visit bills?

   • Check how plans handle Part B coinsurance and whether they have office visit copays (such as some Plan N designs).

3. Am I concerned about providers who charge more than the Medicare-approved rate?

   • Consider whether Part B excess charges coverage is important in your situation.

4. Do I travel outside the U.S.?

   • Look for plans that include foreign travel emergency coverage.

5. Would I rather pay more each month but less when I need care, or the opposite?

   • More comprehensive Medigap plans usually have higher premiums and lower out-of-pocket costs at the time of service.
   • Cost-sharing plans usually have lower premiums but more cost at the point of care.

Medigap vs. Other Types of Coverage

It can also help to be clear on what Medigap isn’t:

• Medigap vs. Medicare Advantage (Part C)

  • With Medicare Advantage, you get your Medicare benefits through a private plan that often includes drug coverage and may have networks.
  • With Medigap, you stay in Original Medicare and add a supplemental policy to help pay your share of costs.
  • You generally cannot use a Medigap plan with Medicare Advantage.

• Medigap vs. Part D

  • Part D covers prescription drugs.
  • Medigap covers cost-sharing for Part A and B medical services, not medications.

Many people on Original Medicare choose a combination of:

• Original Medicare (Parts A & B)
• A Medigap plan
• A Part D drug plan

Key Takeaways: What a Medigap Plan Covers

To wrap it up, here are the major points about what Medigap plans cover:

• Every Medigap plan covers:

  • Part A coinsurance and up to 365 extra days of hospital care
  • Part B coinsurance or copayments (at least partially)
  • First 3 pints of blood
  • Hospice care coinsurance or copayments under Part A

• Many Medigap plans also cover:

  • Skilled nursing facility care coinsurance
  • Part A deductible
  • Part B deductible (only certain plans, and only for those eligible before 2020)
  • Part B excess charges
  • Limited foreign travel emergency care

• Medigap plans do not cover:

  • Prescription drugs (Part D covers these)
  • Routine dental, vision, or hearing services
  • Long-term custodial care
  • Most care outside the U.S., beyond limited emergency benefits in some plans

Understanding these coverage details can help you choose a Medigap plan that fits your health needs, budget, and preferences, and avoid unexpected gaps in your Medicare coverage.