In order to be eligible for our plan, you must have Medicare Part A and Medicare Part B. For that reason, some plan members must pay a premium for Medicare Part A and most plan members must pay a premium for Medicare Part B to remain a member of the plan. For most of your medical services or drugs covered by the plan, you must pay your share of the cost when you get the service or drug. This will be a copayment (a fixed amount) or coinsurance (a percentage of the total cost).