Monthly premium - most drug plans charge a monthly fee that varies by plan. Payment is in addition to the Part B premium. The monthly premium for a Medicare Advantage Plan (like an HMO or PPO) or a Medicare Cost Plan that includes Medicare prescription drug coverage may roll in an amount for prescription drug coverage.
Yearly deductible - Amount paid for prescriptions prior to plan begins to pay. Some drug plans don't have a deductible.
Copayments or coinsurance - Amounts paid at the pharmacy for covered prescriptions after the deductible. You pay your share, and your drug plan pays its share for covered drugs.