Medicare Part D Late Enrollment Penalty: How to Check Your Notice

Start with the Part D notice and its deadline

Find the letter that says you owe a Medicare Part D late enrollment penalty, the date on it and the number of uncovered months listed. Keep the envelope and any earlier request for information about your drug coverage. These papers can require different actions.

A request for prior-coverage information gives you a chance to tell the drug plan about coverage it may not know you had. Respond by the deadline on that request. If you already received a penalty letter and disagree, the current LEP reconsideration form says to request reconsideration within 60 days from the date on the letter stating you must pay a penalty. Do not treat a phone inquiry as a substitute for following those filing instructions.

First confirm which charge you are checking. A Part D penalty concerns drug coverage. It is separate from a Part B penalty and from an income-related premium adjustment. If the notice is for Part B instead, use our Part B penalty calculator guide for that different calculation; the Part B tool does not calculate a Part D penalty.

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Rebuild the creditable-drug-coverage timeline

A Part D penalty may apply after a gap of 63 or more days in a row without Part D or other creditable prescription-drug coverage after your Initial Enrollment Period ends. Creditable coverage is expected to pay, on average, at least as much as Medicare drug coverage. Whether you used few prescriptions or paid a low premium does not establish that the coverage was creditable.

Ask the former employer, union or insurer for its written creditable-coverage notice and the dates your drug coverage began and ended. Medicare’s Part D penalty fact sheet explains why this information matters when the new plan checks for a coverage gap. Keep a copy even if you think the plan already has the information.

Build a private record with the dates from your documents, not just the dates you remember. Mark anything that needs confirmation rather than filling an unknown month with an assumption.

The 63-day rule is not a promise that you can wait that long and then start any plan immediately. Enrollment periods and coverage start dates are separate questions. Our Medicare enrollment periods guide explains that timing; do not apply the Part B employment-coverage clock to your drug coverage.

For the penalty calculation, Medicare uses full uncovered months. Do not turn a total number of days into months by simply dividing by 30. Ask the plan which months it used and how it treated the beginning and end of the gap. CMS’s creditable-coverage guidance provides the official framework.

Check the 2026 Part D penalty calculation

For 2026, the calculation uses the national base beneficiary premium of $38.99. Multiply 1% of that amount by the number of full uncovered months, then round the resulting monthly penalty to the nearest $0.10. The national base is not the premium charged by your chosen drug plan.

Here is an original fictional check of the arithmetic. Suppose Jordan’s notice lists 19 full uncovered months and the charge is for 2026. Assume, for this calculation only, that those months count and no exception applies. Jordan would check the notice this way:

Jordan is unsure whether two of those months were covered by an employer drug plan. Matching the arithmetic does not prove the month count is correct. Jordan marks those months as unconfirmed, asks the former plan for written coverage evidence and follows the penalty letter’s review instructions. This example does not establish Jordan’s eligibility or predict the review outcome.

The Medicare penalty guidance explains that the national base can change each year, so the dollar penalty can change too. The 2026 example is not a 2027 quote or a lifetime cost estimate. A zero-premium drug plan does not by itself erase a penalty, and switching plans generally does not end it.

Check Extra Help and other relevant circumstances

You are not charged a Part D late enrollment penalty while you are getting Extra Help. Keep the notices showing the relevant dates, and ask the plan to check them against the period at issue. Our Extra Help application checklist explains automatic help, the application route and follow-up. Applying for assistance is not the same as receiving an eligibility decision.

If the disputed period includes circumstances you believe affected your ability to enroll, describe them accurately and follow the evidence instructions on the official reconsideration form. Do not assume that checking a box guarantees an exception. If your Medicare history began before age 65, ask the plan which enrollment period and penalty rules it used for your notice.

Use the Part D penalty reconsideration route

If you disagree with the penalty, start with CMS’s Late Enrollment Penalty Appeals page and the instructions supplied with your notice. This is the LEP reconsideration process, which is different from appealing a denial of a prescription drug.

Complete and sign the applicable request form, explain why you disagree and attach the relevant coverage evidence. The current form gives the mailing or fax instructions and requires filing within 60 days from the date on the penalty letter. If more than 60 days have passed, include an explanation for the delay as instructed; acceptance is not guaranteed. Check the current form and your notice rather than relying on an old contractor address found online.

The form also explains what to do if you do not know whether prior drug coverage was creditable: you can ask the former plan in writing and attach your request and any response. Do not wait for that answer before sending the reconsideration request. Keep a copy of what you submit and evidence of transmission.

Use a short explanation that connects the disputed dates to your records. For example: “The notice lists these months as uncovered. I am including the former plan’s letter showing drug coverage during these dates and its creditable status.” This is a writing prompt, not a claim that any particular record will win a case. Use your actual evidence and the official form’s instructions.

Keep Medicare numbers, personal medical information and copies of notices in your private records and the official submission process. Retire Companion does not need those documents. If someone is helping you act as a representative, check the representation instructions on the current form.

Keep billing and review follow-up separate

Medicare’s fact sheet says to keep paying the penalty with your plan premium while the reconsideration is pending so your drug coverage is maintained. Do not stop payment solely because you asked for review. If you have a billing question, contact the plan and keep a record of the answer.

After filing, record the submission date, the disputed months, the documents sent and the next follow-up contact. Read any request for more information and the decision notice. A completed checklist does not mean the penalty has been removed, and no refund or decision date is promised by this guide.

If you are still responding to the plan’s earlier request about prior coverage, follow its printed deadline. CMS’s 2026 Part D penalty guidance treats the coverage-information process and later reconsideration as different steps. Keep the two letters and their deadlines labelled separately.

Our editorial policy explains how we use sources. The record table, Jordan example and writing prompt are Retire Companion planning aids. They do not decide which months count, replace an official notice or provide a professional benefits determination.