How to Choose a Medicare Supplement (Medigap) Plan

Original Medicare is solid coverage, but it leaves some real financial exposure: hospital cost-sharing with no annual cap, 20% coinsurance on outpatient care, and deductibles that can add up quickly. Medigap plans -- also called Medicare Supplement Insurance -- are private policies designed to fill those gaps.

The challenge is that there are ten standardized plan types (labeled A through N), dozens of companies selling them, and prices that vary wildly for identical coverage. Here is how to cut through the noise.

Understanding Standardized Plans

This is actually good news: unlike most insurance shopping, Medigap plans with the same letter are legally required to offer the same benefits regardless of which company sells them. A Plan G from Humana and a Plan G from Mutual of Omaha cover exactly the same things. The only differences are price, customer service, and company stability.

That means your job is to find the right plan letter first, then shop on price among reputable carriers.

The Plans Worth Knowing

There are ten letters, but most people end up seriously considering just two or three. Here is an honest assessment of the most popular options.

Plan G: The Most Comprehensive Option Available

Plan G covers almost everything Original Medicare does not: the Part A hospital deductible, Part A coinsurance and hospital costs (up to 365 additional days after Medicare benefits end), Part B coinsurance (that 20% you would otherwise owe), skilled nursing facility coinsurance, foreign travel emergency care, and excess charges.

The one thing Plan G does not cover is the Part B deductible (around $250 in 2026). You pay that once per year, and after that, your out-of-pocket medical costs are essentially zero for covered services. Plan G became the top-selling Medigap plan after Plan F was closed to new enrollees in 2020.

Plan N: Lower Premium, Some Cost-Sharing

Plan N covers most of the same things as Plan G, with two differences. You may pay up to a $20 copay for office visits and up to a $50 copay for emergency room visits (waived if you are admitted). Plan N also does not cover excess charges -- the rare situation where a doctor charges above the Medicare-approved amount.

Plan N typically costs $30 to $60 less per month than Plan G. If you are healthy and do not see doctors frequently, the math often works in Plan N's favor. If you see doctors regularly, Plan G's zero-copay structure may save you more over time.

Plan K and Plan L: Lower Premiums with Shared Costs

These plans cover a percentage of your cost-sharing rather than all of it, in exchange for lower monthly premiums. They also have annual out-of-pocket limits. They are worth looking at if you want basic protection against a catastrophic bill but are comfortable with more day-to-day cost exposure.

Plan A: Basic and Often Not Worth It

Plan A is the minimum Medigap coverage -- it only covers Part B coinsurance and a few other limited benefits. The premiums are lower, but you are still exposed to the Part A deductible, which can be over $1,600 per hospital admission in 2026. Most people are better served by Plan G or N.

How to Compare Prices

Since coverage is identical by plan letter, price is your primary differentiator. Here is how to shop effectively.

Use your state's SHIP (State Health Insurance Assistance Program). Every state has free counselors who can give you unbiased comparisons for your area. No sales pressure, no commissions. Find them at shiphelp.org.

Check Medicare's plan finder. Medicare.gov has a tool that shows Medigap policies available in your zip code with estimated premiums.

Get quotes from at least three carriers. Prices for identical Plan G coverage can vary by $50 to $100 per month or more for the same person in the same area. eHealthInsurance and GoHealth are two online marketplaces that let you compare multiple carriers quickly.

Look at the company's rate history. A low premium today does not help if the company raises rates aggressively every year. Ask about the carrier's rate increase history in your state over the past five years. A reputable independent broker can pull this data for you.

Pricing Methods to Watch For

Medigap insurers use three methods to set premiums, and the method affects your long-term costs.

Community-rated: Everyone in the area pays the same premium regardless of age. Rates go up due to inflation, not because you get older. Generally the best deal if you plan to keep the policy for many years.

Issue-age rated: Premium is based on the age you are when you first buy the policy. Buying young locks in a lower base rate.

Attained-age rated: Premium increases as you get older, in addition to general inflation increases. These plans often start cheapest but become the most expensive over time. Be cautious here.

What Medigap Does Not Cover

Medigap supplements Original Medicare -- it does not add new benefits. It will not cover dental, vision, hearing, or prescription drugs. For prescriptions, you still need a separate Part D plan. For dental and vision, you need a standalone plan or a Medicare Advantage plan that includes them (though you cannot have both Medigap and Medicare Advantage at the same time).