Understanding Medicare Supplement (Medigap) Plans A Through N

Medigap plans fill the gaps in Original Medicare coverage. Compare all 10 standardized plan types to find the right supplement for your needs.

If you choose Original Medicare, you'll quickly realize it doesn't cover everything. You're responsible for deductibles, copayments, coinsurance, and there's no cap on out-of-pocket spending. That's where Medicare Supplement Insurance — commonly called Medigap — comes in. These standardized plans, sold by private insurers, help pay the out-of-pocket costs that Original Medicare doesn't cover.

Key Fact

Medigap plans ONLY work with Original Medicare (Parts A & B). You cannot use a Medigap policy if you're enrolled in a Medicare Advantage plan.

The 10 Standardized Medigap Plans

Medigap plans are standardized by the federal government, meaning Plan G from one insurer covers the exact same benefits as Plan G from another insurer. The only differences are price and customer service. Here's what each plan covers:

*Plans C and F are only available to people who became eligible for Medicare before January 1, 2020. **Plan N requires copays of up to $20 for office visits and up to $50 for ER visits that don't result in admission.

Most Popular Medigap Plans in 2026

Plan G — The Gold Standard

Plan G is the most popular Medigap plan for people who became Medicare-eligible after 2020. It covers everything except the Part B deductible ($276/year in 2026). Monthly premiums typically range from $120–$300 depending on your age, location, and the insurer. For most people, Plan G offers the best balance of comprehensive coverage and reasonable premiums.

Plan N — The Value Choice

Plan N is growing in popularity as a lower-cost alternative to Plan G. It doesn't cover Part B excess charges or the Part B deductible, and it requires small copays for some visits. However, premiums are typically 15–30% lower than Plan G. If your doctors all accept Medicare assignment (meaning they don't charge excess), Plan N can save you significant money.

Plans K and L — Budget Options

Plans K and L offer partial coverage (50% and 75% respectively) of most benefits but include an annual out-of-pocket cap. Once you hit the cap, the plan pays 100% for the rest of the year. These can work well for generally healthy people who want catastrophic protection at a lower premium.