Medicare Part D is an optional federal program that helps Medicare beneficiaries pay for self-administered prescription drugs. It is offered through private insurance companies approved by Medicare.

Anyone with Medicare Part A and/or Part B is eligible for Medicare Part D. You must also live in the plan’s service area.

You can get Part D either through a stand-alone Prescription Drug Plan (PDP) or as part of a Medicare Advantage Plan (Part C) that includes drug coverage.

It helps lower your prescription drug costs and protects you against high out-of-pocket expenses for medications.

A formulary is a list of prescription drugs covered by a Part D plan. Each plan's formulary is different, but they must all cover at least two drugs in each drug category.

Many formularies categorize drugs into tiers. For example, Tier 1 is typically for low-cost generic drugs, while higher tiers are for brand-name, non-preferred, or specialty drugs with higher co-pays or co-insurance.

Part D plans cover a wide range of prescription drugs, including those for chronic conditions and temporary use, like antibiotics. They must cover certain categories of drugs, such as HIV/AIDS treatments and antidepressants.

Generally, Part D does not cover drugs for cosmetic purposes, fertility, weight loss or gain, or over-the-counter medications. It also does not cover most vitamins and minerals.

Costs typically include a monthly premium, an annual deductible (which can be waived by some plans), and co-pays or co-insurance for your prescriptions.

If you don’t sign up for a Part D plan when you are first eligible and don't have other creditable drug coverage, you may have to pay a late enrollment penalty. This penalty is added to your monthly premium for as long as you have Part D coverage.

The penalty is 1% of the national base beneficiary premium for every full, uncovered month you were eligible but didn't have Part D or other creditable drug coverage.

The Initial Enrollment Period is a 7-month window around your 65th birthday. The Annual Enrollment Period runs from October 15 to December 7 each year, allowing you to join, switch, or drop a plan. Special Enrollment Periods are available for specific life events.

The "donut hole," or coverage gap, was a temporary limit on what a Part D plan would pay for drugs. While it still exists, all Medicare plans now have a $2,000 cap on out-of-pocket spending on covered drugs. Once you reach that cap, you enter catastrophic coverage.

After you reach a certain amount of out-of-pocket spending ($2,000 in 2025), you enter the catastrophic coverage phase. During this phase, you pay nothing for covered Part D drugs for the rest of the year.

"Extra Help," also known as the Low-Income Subsidy (LIS), is a Medicare program that helps people with limited income and resources pay for their Part D premiums, deductibles, and co-pays.

To qualify, you must have limited income and resources and be enrolled in a Part D plan. You may automatically qualify if you have full Medicaid coverage or receive Supplemental Security Income (SSI).

Yes, you can have a stand-alone Part D plan in combination with Original Medicare and a Medigap (Medicare Supplement) policy. Medigap policies do not cover prescription drugs, so you would need a separate Part D plan for that coverage.

You can lower your costs by choosing a plan with a low premium, using in-network pharmacies, and opting for generic or preferred brand-name drugs on your plan's formulary.

Yes, a plan can change its formulary at any time, but it must notify you when changes are made.

You can request a formulary exception from your plan, which asks them to cover a drug not currently on their list. If the exception is denied, you have the right to file an appeal.