Best Rated Medigap Insurance Companies: How to Read the Ratings Yourself

AM Best’s Financial Strength Rating is an opinion of an insurer’s ability to meet its ongoing obligations to policyholders. The scale runs in pairs of letters with a plain-English label for each band.

Grade labels per AM Best’s published scale. Separate codes cover companies under regulatory supervision, in liquidation or with a suspended rating.

The National Association of Insurance Commissioners publishes complaint data reported by state insurance departments. Its complaint index compares two shares for one line of business, in one state or nationally, for one year.

A worked example: an insurer that writes 5% of a state’s Medicare Supplement premium but draws 2.5% of its complaints has an index of 0.50, half the expected complaint level. One writing 5% of premium with 10% of complaints scores 2.00, double the expected level.

Large Medigap brands often sell through several legal companies, and the one assigned depends on your state. Ratings and complaint records are filed under those legal names, so the first job is finding the name printed on the outline of coverage.

Source: AM Best rating release on CVS Health Corporation’s Aetna subsidiaries, June 2026, and Aetna outlines of coverage for Missouri and South Carolina. Our compilation.

The Aetna group happens to carry the same grade across these companies. Other brands do not always, so check the specific issuer each time. A review of the Aetna Plan G product itself is in our Aetna Medigap Plan G reviews.

Indiana is one example of a state that publishes yearly complaint index reports by line, using the same share-of-complaints over share-of-premium logic. Checking your own state’s version adds local data that a national list cannot show.

A financially superior company can still raise Medigap rates steeply, and a smaller one can price steadily. That is why ratings should screen companies in or out, while price and rate history decide among the companies that pass.

Federal law sets minimum loss ratios for Medigap: individual policies are expected to return at least 65% of premiums as benefits over time, and group policies at least 75%. Insurers report Medicare Supplement experience to regulators each year, and some states publish it.

Our guide to the best Medicare Supplement companies and plans for 2027 covers which letters suit which buyers, and Medigap plan costs explains pricing methods in depth.