Medicare Part D is the prescription drug benefit with Medicare program. This program helps cover the cost of prescription drugs, including brand-name and generic medications, and is available to anyone who is eligible for Medicare, regardless of income or health status. These plans, while regulated by the federal government, are offered by insurance companies.

To enroll in a Medicare Part D plan, you must first have either Medicare Part A or Part B. You can enroll during the initial enrollment period when you first become eligible for Medicare, or during the annual open enrollment period from October 15th to December 7th each year.

Once enrolled, you will typically pay a monthly premium for your Medicare Part D coverage, along with any applicable deductibles, copays, and coinsurance. The exact cost and coverage details will vary depending on the specific plan you choose.

It's important to note that if you don't enroll in a Medicare Part D plan when you're first eligible and you don't have other creditable prescription drug coverage, you may have to pay a late enrollment penalty if you decide to enroll later. So, it's important to carefully consider your options and enroll in a plan that meets your prescription drug needs and budget.