Medicare Supplement Plan Comparison Calculator

Compare Medigap plans G, N, F (legacy), and High-Deductible G side-by-side. Plug in your premium quotes and expected medical use to see annual cost, total out-of-pocket, and 10-year lifetime cost — based on 2026 Medicare deductibles and your real situation.

For Plan N $20 copay calculation
For Plan N $50 ER copay
Premium Quotes (Annual)
Only available if eligible before 2020
Inflation & Time Horizon
Medigap premiums typically rise 3-8%/year
Ad Space

What Are Medicare Supplement (Medigap) Plans?

Medicare Supplement Insurance (Medigap) is private insurance that fills gaps in Original Medicare (Parts A and B) — covering things like coinsurance, copays, and deductibles. There are 10 standardized Medigap plans (A, B, C, D, F, G, K, L, M, N) plus a high-deductible version of G and F. Standardization means a Plan G from one insurer covers exactly the same medical services as a Plan G from any other insurer; only the premiums differ (source: medicare.gov medigap).

Plan G is the most popular for new enrollees, covering everything except the small Part B deductible ($240 in 2026). Plan F is similar but covers the Part B deductible too — only available to enrollees eligible before January 1, 2020. Plan N is cheaper than G but charges $20 office copays and $50 ER copays. High-Deductible Plan G (HDG) has the lowest premium but you pay $2,800 (2026 deductible) before benefits kick in (source: cms.gov).

How to Use This Calculator

Enter quotes from at least 2 different insurers for each plan you are considering. Quotes vary widely — by state, by insurer, and by your age/health. Then estimate your typical annual doctor visits and ER trips. The calculator will compute total annual out-of-pocket (premium + copays + deductibles) for each plan, plus a 10-year projection accounting for premium inflation.

Common pattern: Plan N can save $300-500/year on premium for healthy enrollees with under 15 doctor visits. Plan G is safer for those with chronic conditions or unpredictable care. HDG is highest-risk/highest-reward — great if you stay healthy, costly in a heavy-use year.

Premium Inflation — The Hidden Cost

Medigap premiums typically rise 3-8% per year due to medical inflation and age-related underwriting. After 10 years, a $1,800 Plan G premium becomes $3,200 at 6% annual inflation — even though you might think you "locked in" a price. Always project forward at least 10 years when comparing plans.

Some insurers offer "issue-age" pricing (premium based on age when you enrolled, slower increases) vs "attained-age" (rises with each birthday — common but more expensive long-term). Ask your insurer which method they use.

What Medigap Does Not Cover

Medigap does not cover prescription drugs (you need Part D), dental, vision, hearing aids, or long-term care. Many enrollees pair Medigap with a Part D plan and a separate dental/vision plan. For long-term care, see our long-term care insurance calculator. For income-based premium tiers (IRMAA), use the IRMAA calculator.

Last updated April 2026. Sources: medicare.gov, cms.gov, naic.org.