Medicare offers prescription drug coverage to everyone with Medicare. If you decide not to join a Medicare Prescription Drug Plan (Part D) when you're first eligible, or if you decide not to join a Medicare Advantage Plan (Part C) (like an HMO or PPO) or other Medicare health plan that offers Medicare prescription drug coverage, you'll likely pay a late enrollment penalty unless you have other creditable prescription drug coverage, or you get Extra Help.

To get Medicare drug coverage, you must join a plan run by an insurance company or other private company approved by Medicare. Each plan can vary in cost and drugs covered.

Two ways to get drug coverage:

1. Medicare Prescription Drug Plan (Part D). These plans (sometimes called "PDPs") add drug coverage to Original Medicare, some Medicare Cost Plans, some Medicare Private Fee-for-Service (PFFS) Plans, and Medicare Medical Savings Account (MSA) Plans.
    
2. Medicare Advantage Plan (Part C) (like an HMO or PPO) or otherMedicare health plan that offers Medicare prescription drug coverage. You get all of your Medicare Part A (Hospital Insurance)and Medicare Part B (Medical Insurance) coverage, and prescription drug coverage (Part D), through these plans. Medicare Advantage Plans with prescription drug coverage are sometimes called “MA-PDs.” You must have Part A and Part B to join a Medicare Advantage Plan.

What Drug Plans Cover:

Each Medicare Prescription Drug Plan has its own list of covered drugs (called a formulary). Many Medicare drug plans place drugs into different "tiers" on their formularies. Drugs in each tier have a different cost.

A drug in a lower tier will generally cost you less than a drug in a higher tier. In some cases, if your drug is on a higher tier and your prescriber thinks you need that drug instead of a similar drug on a lower tier, you or your prescriber can ask your plan for an exception to get a lower copayment.

A Medicare drug plan can make some changes to its formulary during the year within guidelines set by Medicare. If the change involves a drug you’re currently taking, your plan must do one of these:

• Provide written notice to you at least 60 days prior to the date the change becomes effective.
• At the time you request a refill, provide written notice of the change and a 60-day supply of the drug under the same plan rules as before the change.