Medicare Part D: Prescription Drug Plans

Western Wind Insurance & Investments can help you find the prescription drug coverage that works for you, to protect your health and your budget.

What is Medicare Part D?

Medicare Part D is prescription drug coverage offered by private insurers and regulated by Medicare. You should enroll in a Part D plan when you first become eligible for Medicare if you have:


  • Original Medicare Part A (hospital) and/or Part B (medical)

  • A Medicare Advantage (Part C) plan that doesn’t include drug coverage

Important Note: Part D plans are not legally required, but unless you have other creditable drug coverage, it’s financially risky to skip Part D. Even if you don’t take many prescriptions now, it’s smart to enroll in a low-cost plan when you become eligible to avoid lifetime penalties and limited access.

Choosing a Prescription Drug Plan

Selecting the right Part D plan involves these key factors:


  • Costs: Compare plans’ monthly premiums, annual deductibles, and coinsurance.

  • Drug Coverage (Formulary): Review each plan's list of covered drugs, which are generally organized into tiers that will determine your out-of-pocket cost. Make sure your medications are covered at a level you can afford, and check for any restrictions like prior authorization or quantity limits.

  • Pharmacy Network: Verify that the pharmacies you use are included in the plan’s network. Some plans offer discounts if you use their preferred pharmacies or mail-order platforms.

Note: Medicare’s rules for out-of-pocket limits and drug tiers are updated annually, so check with us to make sure you have the latest information.

Enrolling in Part D Plans

There are a few times throughout the year when you can enroll in Medicare Part D coverage:


  • Annual Enrollment Period (AEP): October 15 to December 7 every year; change, switch, or leave Part D plans. It is crucial to review and adjust coverage every year based on changing needs and formularies.

  • Initial Enrollment Period (IEP): The seven-month window when you first become eligible for Medicare (starts three months before your 65th birthday month and ends three months after).

  • Medicare Advantage Open Enrollment (OEP): January 1 to March 31 every year; switch Advantage plans or return to Original Medicare and join a standalone Part D plan.

  • Special Enrollment Periods (SEPs): Certain life events, such as moving to a new state or losing creditable drug coverage, may qualify you to change enrollment.

The Late Enrollment Penalty

The Social Security Administration applies this penalty to your Part D plan premium if you enroll in a Part D plan and one of the following is true:


  • It has been more than 63 days since you became eligible for Medicare and you don’t have creditable coverage
  • It has been more than 63 days since your creditable coverage lapsed or ended

The penalty is calculated based on the number of months you went without drug coverage once you were eligible. This increases your premium permanently. So the longer you wait, the more you will pay for the duration of your plan.

A young man is helping an older man with his medication.

What is Creditable Drug Coverage?


This refers to prescription coverage through another source that’s considered equal to or better than Part D. Examples include VA benefits, TRICARE, and some employer or union plans. If you have one of these, you should get a Notice of Creditable Coverage from your plan each year.


If you skip drug coverage when you’re first eligible for Medicare, and if you don’t have creditable coverage, you’ll pay more on your Part D premium permanently if you decide to sign up for a plan later. Similarly, if you lose your creditable coverage, you must switch to a Part D plan within 63 days to avoid the late enrollment penalty.

Part D Frequently Asked Questions

  • Do I need Part D if I don’t take many medications?

    It’s a good idea to enroll when you're first eligible, to avoid future penalties. Even if you don’t take many medications now, a plan with a low premium will offer basic protection in case there’s an unexpected change in your health status.

  • Can I switch Part D plans every year?

    Yes, you can change prescription plans during the Annual Enrollment Period. It’s smart to review your plan annually because drug formularies and costs can change.

  • Where can I find details about my prescription drug plan?

    Create an account on the Medicare.gov website to sign in and securely access your prescription drug plan details.