Medicare Part D — Frequently Asked Questions

Medicare Part D is the federal program that helps Medicare beneficiaries pay for outpatient prescription drugs. Unlike Parts A and B, Part D coverage is delivered through private insurance companies approved by Medicare — not directly by the government. Every Part D plan must meet minimum standards set by the Centers for Medicare & Medicaid Services (CMS).

You can get prescription drug coverage in one of two ways:

• A stand-alone Prescription Drug Plan (PDP) that you add to Original Medicare (Part A and/or Part B).
• A Medicare Advantage Plan with drug coverage (MAPD) that bundles your medical and prescription drug coverage into a single plan.

If you already have drug coverage from an employer, union, or another source, check whether it is "creditable" before enrolling — you may not need Part D at all.

There are three main enrollment windows:

• Initial Enrollment Period (IEP): the 7-month window around your 65th birthday (3 months before, your birthday month, and 3 months after).
• Annual Enrollment Period (AEP): October 15 through December 7 every year. You can join, switch, or drop Part D plans; changes take effect January 1.
• Special Enrollment Period (SEP): triggered by events like moving out of your plan's service area or losing other creditable drug coverage.

Costs vary by plan, but the federal standard benefit sets the boundaries:

• Monthly premium: set by your plan (varies widely by insurer and region).
• Annual deductible: up to $615 in 2026. Some plans charge less or waive it entirely.
• Initial coverage: after the deductible, you typically pay copays or about 25% coinsurance until your out-of-pocket spending reaches $2,100.
• Catastrophic coverage: once you hit $2,100 in out-of-pocket costs, you pay $0 for covered Part D drugs for the rest of the year.
• Insulin: capped at $35 per month per covered insulin product; most adult vaccines recommended by the CDC are $0.

Since the Inflation Reduction Act redesign, Part D has three phases (the old "donut hole" coverage gap was eliminated in 2025):

1. Deductible: you pay 100% of covered drug costs until you meet your plan's annual deductible (no more than $615 in 2026).
2. Initial coverage: you and your plan share costs through copays or coinsurance until your out-of-pocket spending reaches $2,100.
3. Catastrophic coverage: you pay $0 for covered drugs for the remainder of the calendar year.

If you go 63 or more consecutive days without creditable prescription drug coverage after your Initial Enrollment Period ends, Medicare adds a late enrollment penalty to your monthly Part D premium. The penalty is permanent — you pay it for as long as you have Part D coverage. The lesson: don't skip drug coverage unless your other coverage is creditable.

A formulary is your plan's list of covered prescription drugs. Plans organize drugs into tiers (for example: preferred generic, generic, preferred brand, non-preferred brand, specialty), and your tier determines your copay or coinsurance. Formularies can change every year — drugs can move tiers or drop off — so re-check your medications against the formulary every fall before the Annual Enrollment Period ends.

Creditable coverage is prescription drug coverage that is at least as good as standard Medicare Part D — typically from an employer, union, TRICARE, or the VA. If your coverage is creditable, you can delay Part D enrollment without facing the late enrollment penalty. Your plan must notify you each year whether its coverage is creditable.

Yes. During the Annual Enrollment Period (October 15 – December 7) you can switch from one stand-alone drug plan to another, join a plan for the first time, or move between Original Medicare + PDP and Medicare Advantage with drug coverage. You should review your plan every year — premiums, deductibles, formularies, and pharmacy networks all change.

Extra Help (the Low-Income Subsidy, or LIS) is a federal program that helps people with limited income and resources pay Part D premiums, deductibles, and copays. If you qualify for Medicaid, SSI, or a Medicare Savings Program, you may qualify automatically. Others can apply through Social Security. Extra Help can be worth thousands of dollars per year.

The Medicare Prescription Payment Plan lets you spread your out-of-pocket Part D drug costs across the calendar year in monthly payments, instead of paying large amounts at the pharmacy counter. It doesn't lower your total costs — it smooths them out. Enrollment is voluntary and the plan auto-renews each year unless you opt out.

A stand-alone PDP pairs with Original Medicare and only covers drugs — you keep full freedom to see any Medicare-accepting doctor. An MAPD (Medicare Advantage with drug coverage) bundles hospital, medical, and drug coverage, often with extra benefits like dental or vision, but usually with provider networks and prior-authorization rules. The right choice depends on your doctors, medications, travel habits, and budget.