Medicare Part D
Written By John O'Hara 6/18/2025
Key Points
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Medicare Part D is available through Stand-Alone PDPs (with Original Medicare) or MAPDs (Medicare Advantage plans)
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You can enroll in Part D plans during your Initial Enrollment Period or change plans annually during Open Enrollment (October 15 - December 7)
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You can sometimes change plans using Special Enrollment Periods tied to major life events
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Plans may have coverage rules like prior authorization, quantity limits, and step therapy requiring you to try lower cost alternatives first
Introduction
Medicare Part D often feels like the most confusing part of Medicare. We hope this article can help you better understand your prescription drug coverage with Medicare!
What is Medicare Part D?
Part D is available through two options: Stand-Alone Prescription Drug Plans (PDPs) or Medicare Advantage plans with prescription drug coverage (MAPDs).
Stand-Alone PDPs are separate private insurance policies you get in addition to Original Medicare and your Medicare Supplement. Here you are responsible for a monthly premium and copays for your prescriptions at the pharmacy. Most people pay $15-30 for their prescriptions, but it can be much higher depending on your particular set of drugs.
MAPDs are Medicare Advantage plans that contain prescription coverage. Unlike Stand-Alone PDPs, these plans often have no monthly premium. You will still be responsible for drug copays at your pharmacy.
When Do I Start Medicare Part D?
Both Stand-Alone PDPs and MAPDs can be applied for during your Initial Enrollment Period. This is the three months before, the month of, and three months after turning 65 or joining part B for the first time. You can also join a PDP or MAPD within 63 days of leaving or losing employer coverage.
When Can I Join Or Change a Medicare Prescription Drug Plan?
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Annual Enrollment Period - Between October 15 – December 7 each year, Medicare allows for anyone to join, switch, or drop their plan. The change will take effect on January 1 as long as the plan gets your request by December 7.
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Initial Enrollment Period - When you’re first eligible for Medicare, you can join during the 7-month period that begins 3 months before the month you turn 65, includes the month you turn 65, and ends 3 months after the month you turn 65.
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Disability Beneficiaries - If you get Medicare due to a disability, you can join during the 7-month period that begins 3 months before your 25th month of disability, includes your 25th month of disability, and ends 3 months after your 25th month of disability. You’ll have another chance to join that starts 3 months before the month you turn 65 ends 3 months after the month you turn 65.
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Extra Help Beneficiaries - If you get Extra Help, you can join, switch or drop a Medicare drug plan anytime during the year.
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Special Enrollment Periods - these periods allow you to switch due to major life events. Example include moving or losing Medicaid.
Can I Switch My Plan Mid Year?
You generally must stay enrolled for the calendar year. However, in certain situations, you may be able to join, switch, or drop Medicare drug plans. Some common examples include:
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If you move out of your plan’s service area
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If you lose other creditable prescription drug coverage
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If you live in an institution (like a nursing home)
How Do I Enroll In Medicare Part D?
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Contact NJ Life and Health Insurance Group; we will walk you through the enrollment by paper or E-app
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Enrolling on the plan’s website or on www.medicare.gov
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Completing a paper application sent directly from the company
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Calling 1-800-MEDICARE or reaching out to your local SHIP office
To enroll, you’ll need your Medicare number and the date your Part A and/or Part B coverage started. This information is on your Medicare card.
What Drugs Are Covered Under Part D?
Each plan has its own list of covered drugs, which is called a Formulary. This list also labels each prescription with a tier ranking, usually between 1-5. This tier ranking will give you a general idea of what the cost will be when you pick it up at the pharmacy.
Tiers 1 & 2 are reserved for generic drugs. These usually include common low cost prescriptions such as cholesterol & blood pressure medication.
Tier 3 & 4 are brand name drugs. These are slightly more expensive, and can include the drugs you see in TV commercials.
Tier 5 is reserved for expensive specialty prescriptions, such as cancer and MS treatment.
Some companies have a Tier 6 tied to diabetes medications.
Are There Limitations With My Part D?
Medicare drug plans may have the following coverage rules:
Prior Authorization - You and/or your prescriber must contact the drug plan before you can fill certain prescriptions. Your prescriber may need to show that the drug is medically necessary for the plan to cover it. This is rare and tends to only happen when the medication is not on your plans' formulary.
Quantity Limits - Limits on how much medication you can get at one time. This is to stop people from buying medications for themselves and their friends and family.
Step Therapy - Your plan may require you to try a low cost prescription before approving a high cost prescription your doctor has prescribed.
About the Author
John O'Hara is a licensed life and health insurance broker and President of NJ Life and Health. He has personally helped hundreds of people with their Medicare needs across several states.