Medicare Supplement plans—also called Medigap—help cover costs that Original Medicare (Part A and Part B) doesn’t fully pay for, such as coinsurance, copayments, and some deductibles. These plans are standardized by the federal government, meaning the benefits for each letter plan (A, B, C, etc.) are the same no matter which insurer you choose. What varies is price, customer service, and additional perks.
This guide compares key Medicare Supplement plans so you can choose the one that fits your health needs and budget.
What Is a Medicare Supplement (Medigap) Plan?
A Medigap plan works with Original Medicare—it doesn’t replace it. You must be enrolled in Medicare Part A and Part B to buy a Medigap policy.
Medigap plans help pay for some of the out-of-pocket costs you’d otherwise pay yourself, like:
- Medicare Part A coinsurance and hospital costs
- Part B coinsurance or copayments
- Skilled nursing facility care coinsurance
- Part A deductible
- Part B deductible (only on some plans)
- Foreign travel emergency care (some plans)
Standardized Medigap Plans in the U.S.
Medicare Supplement plans are labeled with letters. Plans with the same letter must offer the same benefits, no matter the insurance company. Not all plans are available in every state, and some plans (like C and F) may not be sold to new enrollees depending on your Medicare enrollment date.
Here’s a breakdown of common plans:
Plan A — Basic Coverage
Plan A offers the core benefits that all Medigap plans must include:
- Part A coinsurance & hospital costs
- Part B coinsurance or copayment
- First 3 pints of blood each year
- Part A hospice care coinsurance
Good choice if you want basic coverage without extra benefits.
Plan B — Adds Part A Deductible
Includes everything in Plan A plus the Part A deductible.
Slightly more coverage at a modest premium increase.
Plan D — Better Out-of-Pocket Protection
Covers everything in Plan A plus:
- Part A deductible
- Part B excess charges
- Foreign travel emergency (up to plan limits)
One of the most popular plans because it balances benefits and cost.
Plan G — Most Comprehensive for New Enrollees
Includes everything in Plan D plus:
- Part B deductible
Plan G is often seen as the best overall value for people eligible now, because it provides nearly full coverage except for the Part B deductible. It’s especially strong for people with frequent medical care.
Plan N — Cost-Saving Tradeoff Plan
Includes most of Plan D benefits but:
- You may pay small copayments for doctor visits and emergency room use
- Does not cover Part B excess charges
Plan N often has lower premiums than Plan G but requires modest copays.
Plans No Longer Sold to New Medicare Enrollees
Plans C and F were once popular because they covered nearly all out-of-pocket Medicare costs including the Part B deductible. However:
- Plans C and F are not available if you first became eligible for Medicare on or after January 1, 2020.
- If you already have one of these plans, you can generally keep it.
Key Differences at a Glance
| Plan | Part A Deductible | Part B Deductible | Part B Excess Charges | Foreign Travel Emergency |
|---|---|---|---|---|
| A | No | No | No | No |
| B | Yes | No | No | No |
| D | Yes | No | Yes | Yes |
| G | Yes | Yes | Yes | Yes |
| N | Yes | No | No | Yes |
“Part B excess charges” are amounts a doctor can legally charge above Medicare’s set fee if they don’t accept assignment.
How to Choose the Right Medigap Plan
1. Consider your health needs
If you expect frequent doctor visits or hospital stays, a plan with broader coverage (like G) may save money in the long run.
2. Check the total cost, not just premiums
Some plans have lower monthly costs but higher out-of-pocket charges through copays or uncovered services.
3. Compare prices across insurers
Even though benefits are standardized, prices vary by company and location.
4. Think about stability
Older adults often prefer Plan G because it offers strong protection without the Part B deductible.
5. Use guaranteed issue rights if you qualify
In certain situations (like losing employer coverage), insurers must sell you Medigap without medical underwriting.
Enrollment Timing Matters
You have a 6-month Medigap Open Enrollment Period beginning the month you turn 65 and are enrolled in Medicare Part B. During this window:
- Insurers cannot charge more due to health conditions
- You can choose any Medigap plan offered in your state
After this period, insurers may require medical underwriting.
Final Thoughts
Medicare Supplement plans help reduce the uncertainty and out-of-pocket costs of Original Medicare. Plans like G and N are often the most cost-effective for today’s Medicare beneficiaries, while A and B may suit those who want basic coverage at the lowest cost.
Always balance benefits with price in your area, and compare quotes from several insurers before enrolling.