Medicare Part D Enrollment

Fact Checked
Contributing expert: Kelly Blackwell, Certified Senior Advisor®
Updated: February 09, 2022


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Kelly Blackwell
Certified Senior Advisor (CSA)®
Kelly Blackwell
Certified Senior Advisor (CSA)®

Kelly Blackwell is a Certified Senior Advisor (CSA)®. She has been a healthcare professional for over 30 years, with experience working as a bedside nurse and as a Clinical Manager. She has a passion for educating, assisting and advising seniors throughout the healthcare process.

Medicare Part D was added to Medicare in 2006 to help cover the costs of self-administered outpatient prescription drugs. There are two ways to obtain Part D coverage: a standalone prescription drug plan (PDP) or a bundled service with a Medicare Advantage Plan that includes drug coverage (MA-PD).

Part D prescription drug coverage is regulated by Medicare but is sold and administered by Medicare-approved private insurance companies. There are specific periods when you are eligible to enroll in a PDP or MA-PD. Part D is optional, but you may be subject to late penalties if you defer enrollment.

Who Is Eligible For Part D?

Medicare drug coverage is available to everyone who has Medicare. Important points to know:

  • You must be a U.S. citizen or lawfully present in the U.S.
  • You must choose from a plan that is available in your area.
  • To enroll in a standalone PDP, you must have Medicare Part A and/or Part B
  • To enroll in a Medicare Advantage Plan with or without drug coverage, you must have both Medicare Parts A and B.
  • If you enroll in a Medicare Advantage Health Maintenance Organization (HMO) Plan or Preferred Provider Organization (PPO) Plan, you cannot enroll in a standalone PDP.
  • Most HMOs and PPOs include drug coverage. However, if you enroll in a Medicare Advantage Private Fee-for-Service (PFFS) Plan that doesn’t include drug coverage, you can enroll in a standalone PDP.
  • Medicare Advantage Special Needs Plans (SNPs) include drug coverage, so you won’t need to enroll in a standalone PDP.

When Can I Enroll In Part D?

You can enroll in Part D during specific enrollment periods:

  • Initial Enrollment Period. When you first become eligible for Medicare due to age, you can join a plan during the seven-month period beginning three months before you turn 65 and ending three months after.

OR if you are eligible for Medicare due to disability, you can join a plan during the seven-month period beginning three months before your 25th month of getting Social Security or RRB disability benefits and ending three months after.

  • Open Enrollment Period. From October 15 to December 7 each year, you can join, switch, or drop a plan. Your coverage will begin on January 1 (as long as the plan gets your request by December 7).
  • Medicare Advantage Open Enrollment Period. From January 1 to March 31 each year, if you’re enrolled in a Medicare Advantage Plan, you can switch to a different Medicare Advantage Plan or switch to Original Medicare (and join a separate Medicare drug plan) once during this time.
  • April 1 to June 30 each year:
    • If you don’t have Medicare Part A and you enrolled in Medicare Part B during the General Enrollment Period (January 1 to March 31), you can join a standalone PDP. Coverage will start July 1.
    • If you have Medicare Part A and you enrolled in Medicare Part B during the General Enrollment Period (January 1 to March 31), you can join an MA-PD. Coverage will start July 1.
  • Special Enrollment Periods (SEPs): You can make changes to your Medicare Advantage and Medicare prescription drug coverage when special circumstances happen in your life, including but not limited to:
    • You move or lose other insurance coverage
    • Your plan changes its contract with Medicare
    • You get Extra Help to pay for Part D or your eligibility for your State Pharmaceutical Assistance Program (SPAP) changes
    • You become dual-eligible for Medicare and Medicaid
    • A five-star Medicare quality plan becomes available in your area.

Rules about when you can make changes and the type of changes you can make are different for each SEP. Check here for a complete list to see if you can take advantage of a SEP.

How Do I Enroll In Part D?

To enroll in a standalone PDP or a MA-PD, you can:

  • Use Medicare’s Plan Finder
  • Visit the plan’s website to see if you can join online
  • Complete a paper enrollment form that you request from the plan.
  • Call the plan you want to join
  • Call 1-800-MEDICARE (1-800-633-4227). TTY: 1-877-486-2048.

When you join, you’ll give your Medicare Number and the date your Part A and/or Part B coverage started. This information is on your Medicare card.

Will I Have To Pay Late Enrollment Penalties?

You may be subject to late enrollment penalties if there is a period of 63 or more days in a row when you don’t have Medicare drug coverage or other creditable drug coverage.

Medicare defines creditable prescription drug coverage as: “Prescription drug coverage (for example, from an employer or union) that’s expected to pay, on average, at least as much as Medicare’s standard prescription drug coverage. People who have this kind of coverage when they become eligible for Medicare can generally keep that coverage without paying a penalty if they decide to enroll in Medicare prescription drug coverage later.”

The cost of the late enrollment penalty depends on how long you went without acceptable coverage and may change each year based on the national base beneficiary premium ($33.37 in 2022). Medicare calculates your penalty amount by multiplying 1% of the base premium times the number of full, uncovered months you didn’t have coverage. This amount is added to your monthly Part D premium and stays in effect for as long as you have Medicare Part D coverage.

To avoid late enrollment penalties:

  • Enroll in Part D when you are first eligible. Even if you don’t currently take prescription drugs, you will have evidence of coverage to avoid paying late enrollment penalties if you need prescription drugs later. Look for a low monthly premium PDP in your area or consider joining an MA-PD with a zero or low monthly premium.
  • Make sure the drug coverage you have is considered creditable.
  • Enroll in Part D within 63 days if you lose your creditable coverage.
  • Keep records of your creditable coverage as evidence to show your new Medicare plan.

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