I guess my question would be, if (s)he’s a retired fed, why not just use the federal insurance to supplement Medicare. All of the advice on this says to buy the cheapest federal plan to supplement Medicare. All the plans are good but there’s no logic in investing in a high option plan if Medicare is going to be paying the greatest part of the bills———and Medicare is primary in this case.
I’m a retired fed myself and have only the federal insurance and no Medicare Part B. Washington Consumer Checkbook puts out an annual guide to federal health insurance that addresses your topic.