Should I suspend FEHB coverage and just have Medicare Advantage?

If you join an MA plan, you can temporarily suspend your FEHB enrollment and stop paying two sets of premiums. Under the suspend option, you pay the Part B premium and sometimes an extra premium from the Medicare Advantage plan (usually only a few hundred dollars per year and often nothing at all). You can later switch out of Medicare Advantage during any future Open Season and rejoin the FEHB program as if you had never left. 

Suspending your FEHB enrollment generates substantial savings because you'll pay one premium instead of two. How much you'll save depends on the precise benefits the MA plan offers to Medicare enrollees and whether it charges an extra premium. 

Most MA plans are comparable to FEHB plans in hospital and medical benefits, but the prescription drug benefits will not be as good as in the FEHB program because the plans have a coverage gap where you are responsible for all or most drug costs until you reach a catastrophic limit. Additionally, FEHB plans have better catastrophic cost protection than MA plans. MA plans have separate catastrophic protection limits for medical and drug costs that taken together are in almost all cases several thousand dollars a year more than the protection limits in FEHB plans.

Important note: You cannot suspend your FEHB enrollment and join one of the FEHB Medicare Advantage plans. Those plans require you to be enrolled in the FEHB plan to enroll in the Medicare Advantage plan option.