For a Medicare Part D plan, you'll pay:

• A set monthly premium.
• A Part D deductible (if applicable).
• Copayments or coinsurance for your drug costs.
• Costs in the coverage gap (if you reach the gap).
• All your other Medicare or Medicare Supplement costs.
• Medicare Part C plans may include Medicare Part D coverage avoiding the need to pay a separate Part D plan premium

Your actual drug costs can also change based on:

• The drugs you use and if they're covered.
• The plan you choose.
• Using an in-network pharmacy.
• If you get extra help paying for Part D.
• If you have to pay a late enrollment penalty.