Medigap Guide 2026: Plans, Costs, and When to Enroll

What Medigap Covers

Medigap plans are sold by private insurers to supplement Original Medicare (Parts A and B). They do not work with Medicare Advantage plans—you can only use Medigap if you have Original Medicare.

The potential cost-sharing gaps that Medigap can cover include:

• Medicare Part B coinsurance: The 20% you owe on all covered outpatient services, with no cap. This is the most valuable Medigap benefit for most enrollees.
• Medicare Part A deductible: $1,676 per benefit period in 2026. With multiple hospitalizations per year, this adds up fast.
• Medicare Part A coinsurance: $419/day for hospital days 61–90; $838/day for lifetime reserve days.
• Skilled nursing facility coinsurance: $209.50/day for days 21–100 of a SNF stay.
• Part B excess charges: The 15% above Medicare's approved amount that non-participating providers can charge (Plans F and G cover this).
• Foreign travel emergencies: 80% of emergency care costs outside the U.S. after a $250 deductible (Plans C, D, F, G, M, N).
• Part B deductible: $257 in 2026. Only Plan F (not available to new enrollees) covers this.

The 10 Standardized Plan Types

Federal law standardizes Medigap benefits into 10 plan letters. Every insurer selling a given plan letter must offer identical benefits. Not all plan letters are available in all states (Massachusetts, Minnesota, and Wisconsin have their own Medigap systems).

* Plans C and F not available to new Medicare enrollees (eligible on or after Jan 1, 2020). † Plan N has copays: up to $20 for office visits and up to $50 for ER visits.

Plan G vs. Plan F: The Key Comparison

For most people comparing Medigap plans, the decision comes down to Plan G vs. Plan F (for those who can still get F) or Plan G vs. Plan N.

Plan F vs. Plan G

The only difference is that Plan F covers the $257 annual Part B deductible and Plan G does not. This means Plan F covers $257/year more than Plan G. However, Plan F premiums are typically $30–$60/month higher than Plan G. At $30/month higher, Plan F costs an extra $360/year to cover a $257 benefit—making Plan G the better financial deal for most enrollees.

Plan F is also only available to people who became Medicare-eligible before January 1, 2020. If you first became eligible on or after that date, Plan F is not an option.

Plan G vs. Plan N

Plan N is the lower-cost alternative to Plan G. The tradeoff:

• Plan N does not cover Part B excess charges (the extra 15% non-participating providers can charge)
• Plan N has a copay of up to $20 for office visits and up to $50 for ER visits not resulting in admission
• Plan N premiums are typically $30–$80/month less than Plan G

Plan N works well if you primarily see Medicare-participating providers (who cannot charge excess charges) and don't use the ER frequently. If you see non-participating specialists, Plan G's excess charge coverage can be valuable.

When to Enroll

Timing your Medigap enrollment correctly is one of the most important Medicare decisions you'll make.

Your six-month open enrollment window starts the first day of the month in which you are both (1) age 65 or older AND (2) enrolled in Medicare Part B. During this window, any insurer selling Medigap in your state must:

• Sell you any plan they offer
• Cannot deny you for any pre-existing condition
• Cannot charge you more because of your health

This is the only time in most states when you have this unconditional right. Once the six-month window closes, insurers can reject your application or charge you substantially higher premiums based on your health history.

Guaranteed Issue Rights

Outside your open enrollment window, you may still have guaranteed issue rights in specific circumstances. These allow you to buy certain Medigap plans without medical underwriting:

• You lose employer or union coverage and you have Medicare
• Your Medicare Advantage plan leaves your area or stops accepting Medicare
• You move out of your Medicare Advantage plan's service area
• Your Medigap insurer goes bankrupt or violates your contract
• You enrolled in Medicare Advantage for the first time and within your first year you decide to return to Original Medicare

Guaranteed issue rights typically apply to Plans A, B, C, F, K, and L (specific available plans vary by situation). Always check with your state insurance commissioner for the exact plans available under your guaranteed issue right.

Average Monthly Costs

Medigap premiums vary significantly by plan type, your age, your location, the insurer's pricing method, and whether you smoke. General ranges for 2026:

Insurers use three pricing methods that significantly affect long-term costs:

• Community-rated: Same premium for everyone in the area, regardless of age. Premiums don't increase just because you get older. Generally best long-term value.
• Issue-age-rated: Premiums are based on your age when you buy the policy and don't increase as you age. Good long-term value if you enroll young.
• Attained-age-rated: Premiums start low but increase as you age. The most common pricing method. Can become very expensive in your 80s.

What Medigap Doesn't Cover

Even the most comprehensive Medigap plan doesn't cover everything:

• Prescription drugs (need Part D)
• Dental, vision, and hearing care
• Long-term care
• Private-duty nursing
• Medicare Advantage plan costs

How to Shop for Medigap

1. Decide on a plan letter first. For most people: Plan G if you want comprehensive coverage, Plan N if you want lower premiums and see mostly participating providers.
2. Compare prices from multiple insurers. Because benefits are standardized, price is your only differentiator. Use Medicare.gov's Medigap plan finder or a licensed Medicare broker.
3. Ask about the pricing method. Community-rated and issue-age-rated plans tend to be cheaper long-term than attained-age-rated plans.
4. Check insurer financial stability. Look up the insurer's AM Best rating. You want an insurer with an A or better rating.
5. Enroll before your window closes. Don't wait until you have a health event. By then it may be too late to get coverage without medical underwriting.

• Medicare.gov — What Is Medigap?
• CMS — Medigap Policies
• KFF — Medigap Enrollment and Consumer Protections
• NAIC — Medigap Shopper's Guide