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All About Medicare Part D – Prescription Drug Coverage

By Peter Keers April 17, 2023 Health and Fitness

Although Medicare debuted in 1965, prescription drugs were not covered until 2003 when Medicare Part D was rolled out. Here are a few things to know before you decide if you need a Part D plan, and if so, how to choose a plan.

What Part D Covers

Unlike Parts A and B, Medicare Part D coverage is optional and obtained from private companies. The drugs covered by a company’s plan are listed in its “formulary.” Formularies change over time because new drugs become available, companies adjust prices or generic versions of brand-name drugs hit the market.

Drug Pricing Tiers

Part D plans categorize their formularies by “tiers” with differing coinsurance and copayments. Plans use tiers to manage costs by incenting enrollees to use less expensive medications.

1Generic drugsLow
2Preferred brand-name drugsMiddle
3Non-preferred brand-name drugsHigh
SpecialtySpecialized drugs like cancer chemotherapyHighest

What If My Medication Is Not on the Formulary?

Sometimes specialized drugs are not listed on a formulary. In other cases, a Medicare enrollee may feel their drug is classified in the wrong tier. In these situations, the enrollee or their doctor can request an exception from Medicare based on medical necessity.

How to Get Part D

Medicare Part D prescription drug coverage can be obtained in two ways.

  1. An enrollee with Original Medicare (Parts A and B) can obtain Part D via a plan offered by a private company.
  2. Join a Medicare Advantage plan offering prescription drug coverage.

It’s easy to find and compare part D plans. Go to the Explore your Medicare coverage options webpage, enter your zip code and click “Continue.” In the subsequent list, click “Medicare drug plan (Part D)” and then click “Find Plans.” From there, follow the prompts and enter all prescription medications you’re taking. Once you’ve followed all the prompts, a list of plans and their costs will be shown.

Then choose between Original Medicare or a Medicare Advantage to find Part D information.

Note: For many people, it’s a good idea to enroll in Part D when signing up for Medicare. Failing to do so may lead to paying more for the coverage permanently.

How to Compare Plans

When evaluating plans, the key items to compare are:

  1. Monthly premiums
  2. Deductibles, copays and coinsurance.
  3. Pricing tiers.
  4. Coverage gap” conditions.

Comparisons can be a little complicated because of all the variables.

The easiest to compare is Original Medicare plus a separate Part D plan. It gets more complicated when comparing drug coverage in these situations:

  • Original Medicare plus a Medigap plan that includes prescription drug coverage.
  • A Medicare Advantage plan that includes prescription drug coverage.

In making these comparisons, consider Parts A and B provisions along with Part D coverage to find the best fit for your situation.

If you have limited financial resources, you might qualify for help paying your drug costs under Part D. Check the Medicare website for more information.

Enrollment Timelines

Medicare Part D plans can be joined, switched or dropped at various times depending on your situation.

Initial Enrollment – When you first become Medicare-eligible.

Open Enrollment – October 15 to December 7 – Coverage begins January 1.

Medicare Advantage Open Enrollment – January 1 to March 31 – If you are already in a Medicare Advantage plan, switching to a new plan or to Original Medicare can happen during this period.

Special Enrollment – If you have an event like moving or losing other insurance, special enrollment allows you to make changes to your Part D plan outside of other enrollment periods.

You can learn more about Medicare Part D plans by visiting the Medicare website or downloading the latest Medicare and Me handbook. Also, look for my past blog posts on Sixty and Me for more valuable Medicare information. For an even deeper dive, check out my Medicare eBook at Living50+.

Let’s Have a Conversation:

Are you enrolled for Medicare Part D? How did you evaluate which plan was best for you? Did you have a list of medications you needed covered or did you enroll to avoid the penalty? What other tips/suggestions do you have?

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I enrolled in Medicare Part D just to avoid the lifetime penalty. I don’t currently take any prescription drugs so chose the cheapest plan available at just over $7.00 per month. If I need a one time rx, Good RX is often cheaper. It upsets me that I have to pay premiums for something I don’t use or need. I’m sure I will need it someday.


The Author

Peter Keers is a writer and video blogger focusing on topics for the over-50 audience. Defining himself as a curious seeker, Peter’s interests range across both the art and the science of living an authentic and fulfilling life in the 21st century. See Peter’s eBooks on travel, long-term care, Medicare and other topics at

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