I was CSRS and retired 2 months from 65 with a wife 5 1/2 years younger than me. I retained BCBS [Basic] so far it covers evrything that Medicare doesn't cover. Part "B" only pays 80% and BCBS gets the rest including doctors visits coinsurance etc. There is a payment of $150 for emergency room and $125 for Hospital if admitted, $7,000 catastrophic, no other deductable. The Wife is covered 100% by BCBS including Prescriptions. I get the Prescription thing from BCBS all for $321 a month + $104 for Medicare part "B".
So you kept BCBS and picked up Medicare Part "B" as well as Part "A".