Your premium is the amount you pay every month to keep your coverage. Medicare Part B, Part C, and Part D are all subject to premiums, as is Medigap. Although there are some $0 premium Part C plans. Meanwhile, you may qualify for premium assistance based on income for Part B and Part D.
The total premium you’ll pay for Medicare coverage each month is the sum of all your premiums minus any premium deduction offered by your part C plan or any assistance you qualify for with with Part B or Part D premium assistance.