Avoiding the Medicare Part D Late Enrollment Penalty

If you go 63 or more days in a row without Medicare Part D or other creditable prescription drug coverage after your Initial Enrollment Period ends, you may owe a Part D late enrollment penalty. This extra monthly cost is generally added to your Part D premium for as long as you have Medicare drug coverage. Understanding what counts as creditable coverage—and keeping your documentation—can help you avoid an unexpected expense.

At Advantage Insurance Benefits, we help Washington residents make sense of Medicare enrollment decisions in clear, patient-friendly terms. Here is a practical summary of the CMS guidance on the Part D late enrollment penalty.

What Is the Part D Late Enrollment Penalty?

 

Medicare Part D helps cover prescription drugs. If you do not enroll in Part D when you are first eligible, you may still be able to avoid a penalty if you have other creditable prescription drug coverage.

The key timing rule is 63 consecutive days. After your Initial Enrollment Period is over, a gap of 63 days or more without Part D or creditable drug coverage can trigger a late enrollment penalty when you later enroll in a Medicare drug plan. The penalty may apply even if you choose a plan with a $0 monthly premium, because it is added to the plan premium rather than replacing it.

It is also important to know that this is usually not a one-time charge. In general, you continue paying the penalty for as long as you have Medicare drug coverage, although the dollar amount can change from year to year.

What Counts as Creditable Prescription Drug Coverage?

 

Creditable coverage is prescription drug coverage expected to pay, on average, at least as much as standard Medicare drug coverage. It may come from a current or former employer, a union, TRICARE, the Indian Health Service, a Tribe or Tribal organization, an Urban Indian program, or another qualifying health plan.

Your existing plan should tell you in writing whether its prescription coverage is creditable. Do not assume that every employer, retiree, or other health plan will qualify. If you are unsure, contact the plan directly and ask for confirmation. Keep any creditable-coverage notices in a safe place. They can be important if Medicare later needs proof that you did not have a qualifying coverage gap.

For people who are still working past 65, this step can be especially important. Before delaying Part D, review your current drug coverage and confirm its creditable status rather than relying on assumptions.

How Medicare Calculates the Penalty

 

CMS calculates the Part D late enrollment penalty using a straightforward formula: 1% × the national base beneficiary premium × the number of full months without Part D or creditable coverage. The result is rounded to the nearest 10 cents and added to your monthly Part D premium.

For 2026, the national base beneficiary premium is $38.99. Because this base premium can change each year, the penalty amount can change too.

For example, a person who went 17 full months without Part D or other creditable drug coverage would have a 17% penalty. In 2026, 17% of $38.99 equals $6.63, which rounds to $6.60 per month. That $6.60 would be added to the person’s regular Part D plan premium for 2026.

Even a relatively small monthly penalty can add up over time. That is why Advantage Insurance Benefits encourages clients to consider prescription drug coverage as part of the overall Medicare decision—not as an afterthought.

Extra Help May Protect You From a Penalty

 

People who qualify for Medicare’s Extra Help program are not charged a Part D late enrollment penalty while they receive Extra Help. The program can also help eligible individuals with Part D premiums, deductibles, coinsurance, and other prescription drug costs.

If someone later loses Extra Help and then goes 63 or more days without Part D or creditable coverage, a penalty may apply when they enroll again. However, CMS does not count uncovered months that occurred before the person qualified for Extra Help. It also does not count months without creditable coverage during a period when the person was receiving Extra Help.

Eligibility and timing matter. If you believe you may qualify, it is worth getting guidance before making a coverage change.

Respond Promptly When Your Plan Requests Information

 

When you join a Medicare drug plan, the plan reviews Medicare records to identify potential gaps of 63 days or more. If it finds a possible gap, it may send you a notice and a form asking about your prior drug coverage.

Complete, sign, and return that form by the deadline shown on the notice. This is your opportunity to report creditable coverage that may not appear in Medicare’s records. You may also be able to call the plan to explain that you had prior creditable coverage. Waiting too long or failing to respond can lead to a penalty that might have been avoided with timely documentation.

What to Do if You Disagree With the Penalty

 

If you believe the late enrollment penalty is incorrect, you can request a reconsideration. Use the form included with your late enrollment penalty notice and return it to the address or fax number provided within 60 days of the date on the letter.

Include evidence that supports your case, such as a notice from an employer or union plan stating that your prescription drug coverage was creditable. A Medicare contractor that is separate from your plan reviews the request. CMS states that decisions are generally made within 90 days, though additional time may be needed in certain situations.

While the reconsideration is pending, you must continue paying the penalty along with your premium. If the reviewer finds that all or part of the penalty was incorrect, your plan will adjust or remove it and explain whether a refund is due. Failure to pay premiums, including the penalty, can put your Medicare drug coverage at risk.

How a Local Medicare Agent Can Help

 

Medicare rules can feel overwhelming, particularly when you are turning 65, retiring, losing employer coverage, or reviewing options during the Medicare Annual Enrollment Period. Advantage Insurance Benefits provides ongoing support beyond enrollment, including annual policy reviews, to help clients understand plan changes and important deadlines.

Our team serves clients throughout Washington, including the Seattle, Tacoma, Bellevue, Everett, Renton, Bothell, Edmonds, and Burien areas. We can help you prepare questions for your current coverage, understand how Part D fits into your Medicare choices, and identify the documents you may need for your enrollment conversation.

FAQ

 

Is the Part D late enrollment penalty permanent?

In most cases, yes. You generally pay it for as long as you have Medicare drug coverage, although the amount may change annually because the national base beneficiary premium can change.

Can I avoid the penalty if I have drug coverage through work?

Possibly. Ask your employer or plan whether the prescription drug coverage is creditable and keep the written notice confirming its status.

What happens if I ignore the plan’s coverage-history form?

You could receive a late enrollment penalty if the plan cannot verify that you had creditable prescription drug coverage during a potential gap. Return the form by its deadline.

Can I appeal a Part D late enrollment penalty?

Yes. You may request reconsideration using the form included with the penalty notice, generally within 60 days. Submit supporting proof of your creditable coverage whenever possible.

Does Extra Help eliminate the penalty?

You will not be charged a late enrollment penalty while you qualify for Extra Help. Coverage gaps before or during Extra Help generally are not counted toward a later penalty.

This article summarizes CMS guidance published in July 2026 and is for educational purposes. Medicare rules and plan details can change, so consider reviewing your individual situation before making enrollment decisions.