top of page

What does Part D cover?

Part D is the fourth Part of Original Medicare. It offers optional prescription drug coverage. The exact details of coverage depend on the plan and your state. Below is a general outline of the types of medications and coverage that you can expect from Part D.

Part D Overview

Medicare Part D is an optional part of Medicare. While it is not the only way to get prescription drug coverage in Medicare, it is one popular way. In order to enroll, you enroll during the Initial Enrollment Period when you also enroll in Parts A and B. To enroll in Part D, you only have to be enrolled in Medicare Part A. This is different from a Medicare Advantage Prescription Drug plan, in which you have to be enrolled in both Parts A and B of Medicare.

What Part D Covers

The exact details of coverage differ based on the plan and the location. Each plan has a list of prescription drugs they cover, called the formulary. The formulary includes at least 2 drugs in each commonly prescribed drug category. These include both brand-name and generic drugs. However, the formulary may not include the specific medication that you are used to taking. If your physician believes that the alternative will not work for your condition, they can apply for an exception. The formulary keeps your drug costs down, but it does so at the expense of flexibility.

There are also different tiers to Medicare coverage. Tiers allow the insurance company to vary your co-pay depending on the cost of the drug. There are four tiers: Tier 1, Tier 2, Tier 3, and the specialty tier. The higher the tier, the more expensive the drug, and therefore the more expensive the co-pay. Below is a brief guide to understanding the tiers.

  • Tier 1 – lowest copayment; most generic prescription drugs

  • Tier 2 – medium copayment; preferred brand-name prescription drugs

  • Tier 3 – higher copayment; non-preferred, brand-name prescription drugs

  • Specialty tier – highest copayment: very high cost prescription drugs

While the exact copayments will change depending on the plan and formulary, the formulary and the tier is the backbone of anticipating Part D costs.


Part D is the last part of Original Medicare. It offers optional prescription drug coverage. While the exact details depend on the formulary, generally Part D covers many commonly prescribed drug categories. It will cover at least 2 types of medications within each category, but it is not guaranteed to cover the medication you are used to taking. To understand the advantages and disadvantages of Part D, contact us at MedicareMisty today.

Recent Posts

See All


bottom of page