Help pack a million meals for struggling seniors on 9-11. Volunteer today



the medicare drug plan
6 Key Facts

1. Anyone on Medicare can get coverage regardless of income or health.

2. You are not obligated to enroll, but there may be consequences if you don't sign up when you are first eligible to do so.

3. To get Medicare drug coverage, you must select one approved private drug plan among many offering different choices. There is no single government plan.

4. Is your income limited? If you qualify for a part of the program known as "Extra Help." you'll pay very little for your medications.

5. Are your drug costs very high? You'll pay no more than 5 percent of the cost of each prescription after you've spent a certain amount of money out-of-pocket in any one year.

6. Do you have better drug coverage already? You probably won't need Medicare's Part D coverage. But it's wise to check.

most popular


Medicare Prescription Drug Coverage Guide

Part 1: How Medicare Part D Works

Understanding the basics

If a plan doesn’t cover one of my drugs, do I have to switch to an alternative drug immediately?

No. Medicare requires plans to give new enrollees a grace period of at least 30 days, during which plans must cover existing prescriptions for drugs not on their formularies. This applies both to people joining a Medicare drug plan for the first time and to people switching to a new plan after being enrolled in another. People who move into nursing homes receive a 90-day grace period.

During the grace period, it’s important to make arrangements to get the drug you need when the 30 (or 90) days are up. You can either:

  • Ask your doctor if you could switch to a similar drug that is on the plan’s formulary; or
  • Ask your doctor to request that the plan makes an exception to its policy and covers the drug for you because of medical necessity. If you win an exception, the plan will cover your prescribed drug until the end of the year.

What do “prior authorization,” “step therapy” and “quantity limits” mean?

You may see one or more of these terms applied to drugs on a plan’s formulary (its list of covered medications). Or you might be at the pharmacy trying to fill a prescription when you first find out that the drug you need comes with one of these restrictions. They are all methods that plans use to try to keep costs down or, in some case, protect patients’ health. Here’s what they mean:

  • Prior authorization means that you, with your doctor’s help, must get the plan’s approval before it will cover a particular drug (often a high-priced or very potent one). To get approval, your doctor must show why this specific medication is necessary for your health or why alternative drugs might be harmful. (Sometimes this approval is required to clarify whether the drug you are taking falls under Part D or another part of Medicare.  Drugs prescribed in the hospital are usually covered under Part A; those administered in a doctor’s office are covered under Part B; those used at home are covered under Part D.)
  • Step therapy means you must first try a generic or less expensive “preferred” drug to treat your condition to see if it works as well as the one prescribed. If it does, you (and the plan) will save money. If it doesn’t, your doctor can request coverage for the original prescription. Your doctor can also request that the plan waive this restriction if you have already tried less expensive drugs that have not proved effective.
  • Quantity limits does not mean that your supply of drugs will be cut off after a certain time or restricted to a certain number of prescriptions a year. It means that the plan will not cover more than the dosage or quantity it regards as normal to treat your condition, unless your doctor says that a higher dosage or quantity is medically necessary for you and that lesser ones have already proved ineffective.

To get your plan to waive any of these restrictions, you need your doctor to provide a statement saying why it is not appropriate in your case and why your prescribed drug is necessary for your health. If the plan turns down this request for an exception to its policy, you have the right to appeal

Topic Alerts

You can get weekly email alerts on the topics below. Just click “Follow.”

Manage Alerts


Please wait...

progress bar, please wait

Tell Us WhatYou Think

Please leave your comment below.


Discounts & Benefits

From companies that meet the high standards of service and quality set by AARP.

Walgreens 1 discount membership aarp

Members can earn 50 points per $1 spent on select health & wellness products at Walgreens.

member benefit aarp hear usa

Members save 15% on easy listening devices and more at the HearUSA Hearing Shop.

Eye Med 4 Membership Benefit AARP Discount

Members save up to 60% on eye exams and 30% on glasses at Target Optical.

Membership Benefits Discounts Email Genius

Brain boost? Get AARP email for access to memory exercises & more that help you focus.

Rewards for Good

Your Points Balance:

Learn More

Earn points for completing free online activities designed to enrich your life.

Find more ways to earn points

Redeem your points to save on merchandise, travel, and more.

Find more ways to redeem points