Medicare Part D is for prescription drug coverage. Original Medicare, which includes Parts A and B, do not cover the costs associated with purchasing prescription drugs.
This means that anyone enrolled in Original Medicare must either pay for these out-of-pocket, or invest in a Medigap or Medicare Advantage (Part C) plan from a private insurer. Part C that includes Part D is also often called Medicare Advantage Prescription Drug Plan.
There are private plans specifically for drug coverage, or bundled with other plans.
• You are enrolled in Part A and/or Part B
• Live in a service area that covers Part D