Your Medicare   Part D -covered drug costs may change throughout the year. If you notice that the price has changed, it may be because you are in a different phase of your Part D coverage. Four different phases of Part D coverage: Deductible  period Until you meet your Part D deductible, you will pay the full negotiated price for your covered  prescription  drugs. After this, the plan will begin to cover the cost of your drugs. While deductibles can vary from plan to plan, it can't be higher than $435 in 2020, and some plans have no deductible. Initial coverage period   After you meet your deductible, your plan will help pay for your covered prescription drugs. They will pay some of the cost, and you will pay a   copayment   or   coinsurance . How long you stay in the initial coverage period depends on your drug costs and your plan’s benefits structure. For most plans in 2020, the initial coverage period ends after you have accumulated a total ...