Medigap Plan Comparison Calculator

Medigap is one of the few corners of the American insurance market where the product itself is genuinely standardized by law rather than left to each company to define — a fact that makes comparison shopping meaningfully simpler than it is for almost any other type of insurance, once you know it's true.

The standardization comes from the Medigap Modernization Act, which defines a fixed set of plan letters (A, B, D, G, K, L, M, N, plus legacy C and F), each with a specific, legally required set of covered benefits. An insurance company selling 'Plan G' anywhere in the standard system isn't creating its own version of Plan G — it's selling access to the exact same federally defined benefit package every other Plan G insurer sells. What insurers actually compete on is price, financial stability, and customer service — not the underlying coverage itself, which is fixed.

This is precisely the opposite of how Medicare Advantage works, and understanding that distinction is often what causes the most confusion for people comparing the two paths. A Medicare Advantage plan's network, formulary, extra benefits, and cost-sharing are all set independently by each insurer for each specific plan in each specific county — real comparison requires looking at the actual plan documents. A Medigap plan letter's coverage is knowable in advance, the same everywhere (with three state exceptions), before you've even requested a quote.

The plan letters themselves cluster into a few practical groups. Plans C and F were historically the most comprehensive ('first-dollar' coverage, including the Part B deductible itself) — but they're closed to new enrollees as of 2020, available only to people who became Medicare-eligible before that date, a policy change intended to reduce first-dollar coverage's tendency to encourage more utilization than necessary. Plan G has effectively become the modern equivalent for new enrollees — comprehensive except for the Part B deductible itself, which the beneficiary pays once per year before the plan's near-complete coverage kicks in. Plan N sits one notch below: broadly similar to G but with small office-visit and ER copays, and no coverage for Part B excess charges, in exchange for typically the lowest premium among the more comprehensive plan letters. Plans K and L represent a different tradeoff entirely: real cost-sharing (50% or 75% coverage on most benefits) but a hard annual out-of-pocket limit, functioning more like a high-deductible safety net than first-dollar coverage.

Part B excess charges deserve particular attention because they're the single benefit most likely to be misunderstood. In states that permit it, a provider who doesn't 'accept assignment' can charge up to 15% more than Medicare's approved amount for a service — a real, uncapped exposure for anyone without a plan that covers it. Only Plans F and G cover excess charges; every other plan letter leaves the beneficiary responsible for that difference. Eight states prohibit excess charges outright, which is worth checking specifically if this factor is influencing a plan choice, since it makes the distinction irrelevant for residents of those states.