Medicare Part D Late Enrollment Penalty After 63 Days

Opening answer (BLUF)

The Medicare Part D late enrollment penalty is an extra amount added to your monthly drug-plan premium if, after your Initial Enrollment Period ends, you go 63 days or more in a row without Medicare drug coverage or other creditable prescription drug coverage.[1][7] It is not a one-time late fee. Medicare calculates it as 1% of the national base beneficiary premium for each full month you were eligible but went uncovered, then rounds that monthly add-on to the nearest $0.10.[2][4] In 2026 that national base is $38.99, so the surcharge grows with the number of uncovered months and can change from year to year even after it is assessed.[1][6]

North Carolina seniors generally avoid it by joining a Part D plan (or a Medicare Advantage plan with drug coverage) during the first enrollment window, or by keeping creditable drug coverage from an employer, union, VA, or TRICARE plan and using a Special Enrollment Period as soon as that coverage ends.[3][9][13]

How Medicare calculates the Part D late enrollment penalty

Part D is Medicare's optional outpatient drug benefit. North Carolina's Department of Insurance reminds residents that even if you do not use prescription drugs now, you should consider joining a Medicare drug plan when you first become eligible.[11]

The formula is the same whether you enroll in a stand-alone Prescription Drug Plan or in a Medicare Advantage plan that includes Part D. Medicare multiplies 1% times the national base beneficiary premium times the number of full months without Part D or other creditable coverage, then rounds that monthly figure to the nearest $0.10 and adds it to your plan premium.[1][2][4]

Two details surprise many of the families we meet in Greensboro and across the Piedmont. First, the percentage is not applied to your plan's premium. It is applied to the national base beneficiary premium, which CMS set at $38.99 for 2026.[6] That base is a statutory starting point, not the amount any one North Carolina plan charges. Your plan premium can be higher or lower. The penalty still uses $38.99 (in 2026) as the yardstick.[1][2] Second, the add-on stays with you for as long as you have Medicare drug coverage, even if you switch plans later, and even if you later join a plan with a $0 monthly premium.[1][4] The dollar amount can also move when the national base changes from year to year.[1]

Medicare's own 2026 examples make the dollars concrete. If you waited 14 months after you were eligible to join a Medicare drug plan and you did not have creditable coverage, you would pay a 14% late enrollment penalty. Fourteen percent of $38.99 is $5.46, which rounds to $5.50 a month for 2026, added on top of your plan premium.[1] A longer gap costs more. In Medicare's fact sheet, a person who left a drug plan on August 1, 2024, and did not rejoin until January 1, 2026, had 17 uncovered months. Seventeen percent of $38.99 is $6.63, which rounds to $6.60 a month in 2026.[4] Those add-ons do not buy extra coverage. They are the price of a gap that lasted 63 days or longer.

How this penalty is different from the Part B surcharge

We already published a separate guide to the Medicare Part B late enrollment penalty. The two rules are easy to mix up.

The Part B surcharge is counted in full 12-month blocks and is a percentage of the standard Part B premium. The Part D surcharge is counted in full uncovered months and is a percentage of the national Part D base beneficiary premium, not of Part B.[1][2] A gap of 11 months does not create a Part B penalty. The same 11 months without creditable drug coverage can create an 11% Part D add-on if the 63-day continuous-gap rule is met.[1][7]

The enrollment clocks differ too. After a job and the group health plan based on that job end, you generally have eight months to sign up for Part B without a Part B penalty. For Part D, the Special Enrollment Period after you involuntarily lose creditable drug coverage is much shorter: two full months after the month you lose that coverage, or two full months after you are notified that it is no longer creditable, whichever is later.[9] Treating the Part D window as if it were the Part B window is one of the most common mix-ups we see.

Creditable coverage: the protection that keeps the clock from starting

Creditable prescription drug coverage is drug coverage that is expected to pay, on average, at least as much as Medicare drug coverage.[3][5] Federal rules list the types of coverage that can meet that test if their actuarial value is high enough. The list includes group health plans (including the Federal Employees Health Benefits Program and many retiree drug plans), VA coverage, TRICARE, Indian Health Service coverage, qualified State Pharmaceutical Assistance Programs, and certain older Medigap policies that still include drug benefits.[5][8]

You do not have to run the actuarial math yourself. Your current plan must tell you, in writing, whether the drug coverage is creditable.[3] Employers, unions, and other entities that offer drug coverage must send that disclosure to Medicare-eligible people enrolled in the plan, including workers, COBRA enrollees, and retirees. They must send it before October 15 each year, when you join, and when the creditable status changes.[8][15]

Keep that letter. When you later join a Medicare drug plan, the plan may send a form asking whether you had creditable coverage. If you do not complete and return it by the deadline, the plan will not know you were covered, and you can be charged a late enrollment penalty even though you never had a real gap.[3][4] You can also call the plan. Medicare's fact sheet is blunt: returning the form is your chance to document coverage the plan did not already see in Medicare's systems.[4]

Two common situations in the Piedmont fit this rule well.

You or your spouse are still working. As long as the employer or union drug coverage is creditable, you can wait to join a Medicare drug plan or a Medicare Advantage plan with drug coverage. You will not pay the Part D late enrollment penalty so long as you do not go more than 63 days without that creditable coverage.[13] Ask the benefits office, and keep the annual notice. Talk to that office before you enroll in a Medicare drug plan. Medicare warns that you, your spouse, or your dependents may lose employer or union health coverage if you add Medicare drug coverage.[3][11]

You have VA or TRICARE drug coverage. Both are on Medicare's list of coverage that can be creditable.[3][5] Many veterans reasonably keep VA pharmacy benefits and delay Part D. That can be a sound choice when the coverage is creditable and you stay continuously covered. If that coverage later ends, use a Special Enrollment Period rather than waiting for fall Open Enrollment.

A 2025 estimate cited by KFF, drawing on MedPAC, found that around 11% of people with Medicare lack creditable drug coverage.[16] A gap is common enough to plan around, especially when someone turns 65, leaves a job, or assumes a discount card is "good enough." Prescription drug coverage, for this purpose, is insurance. Doctor samples, discount cards, free clinics, and drug discount websites are not drug coverage.[3] Paying cash at the pharmacy does not pause the penalty clock. Individual coverage can be creditable, but only if it meets Medicare's actuarial test. The written notice from that plan is the reliable answer.[8] Most Medicare Supplement (Medigap) policies sold today do not include drug coverage, so Original Medicare plus a supplement still needs a separate Part D plan (or other creditable drug coverage). CMS lists certain older Medigap policies as a possible source of creditable coverage, not Plan G or Plan N.[5]

The 63-day gap that actually triggers the penalty

The legal trigger is a continuous period of 63 days or longer, at any time after the end of your Part D Initial Enrollment Period, during which you were eligible to enroll in a Part D plan, were not enrolled in one, and were not covered under any creditable prescription drug coverage.[5][7] The clock does not start until that first window has ended. The gap has to be continuous. A 50-day break, followed by creditable coverage, is not the same as 63 days in a row.

Medicare counts full months without coverage when it sets the 1% add-on.[2][4] A 63-day gap can still produce a penalty. The percentage then reflects how many full uncovered months piled up after you were eligible. Once a plan determines that you had such a gap, it must notify you in writing and include a reconsideration form.[14] The penalty is part of the premium by law, so you must keep paying it (including while a review is pending) or the plan can disenroll you for nonpayment.[4]

Enrollment windows North Carolina seniors can still use

You cannot join a Medicare drug plan on any random Tuesday. You need Medicare Part A or Part B (either one is enough for a stand-alone drug plan), you must live in the plan's service area, and you must enroll during a defined period.[10][11]

Initial Enrollment Period. This is the cleanest on-time path. When you become eligible because you turn 65, it is a seven-month window: three months before the month you turn 65, your birthday month, and three months after.[10] You may join a Medicare Advantage plan with or without drug coverage, or a stand-alone Part D plan. Coverage start dates depend on whether you enroll before or after your Part A and/or Part B begins.[10]

Yearly Open Enrollment (October 15 through December 7). If you are in Original Medicare, this is the regular chance to join, drop, or switch a stand-alone drug plan. Changes take effect January 1 if the plan has your request by December 7.[10][11] Open Enrollment does not erase uncovered months that already happened.

Medicare Advantage Open Enrollment (January 1 through March 31). This window is only for people already in a Medicare Advantage plan. You can switch Advantage plans or return to Original Medicare and join a separate drug plan.[10][11]

Special Enrollment Periods that protect a delayed start. If you involuntarily lose other drug coverage that is as good as Medicare's, or if that coverage changes and is no longer creditable, you can join a Medicare Advantage plan with drug coverage or a Medicare drug plan. Your chance lasts two full months after the month you lose the coverage, or two full months after you are notified that it is no longer creditable, whichever is later.[9] If you leave employer or union coverage (including COBRA), you may join during the two full months after the month that coverage ends.[9] Put those dates on a calendar as soon as a retirement date is real. Do not assume you have the same eight months you may have for Part B. Moving out of a plan's service area (or into an area with new plan options) opens a window that begins when you move and continues for two full months after the move.[9] If a plan never properly told you that your other private drug coverage was not creditable, or never properly told you that you were losing creditable coverage, you have two full months after the month you get a notice of that error from Medicare or the plan.[9] Federal rules also let someone who was not adequately informed that coverage was not creditable ask CMS to treat that coverage as creditable for penalty purposes.[8]

North Carolina's Seniors' Health Insurance Information Program (SHIIP) walks residents through these same enrollment times. SHIIP counselors are not licensed insurance agents and do not sell or endorse a product, plan, or company. Call 1-855-408-1212 weekdays from 8 a.m. to 5 p.m., or meet a local volunteer counselor by appointment in every North Carolina county.[11][12]

If a plan sends you a late-enrollment letter

A penalty letter is not the end of the conversation. Medicare's fact sheet asks you to request a reconsideration using the form that came with the notice, and to return it within 60 days of the date on the letter.[4] Send proof that supports your case, such as copies of employer or union creditable-coverage notices. If the form is late, you will need to explain why. Joining a different plan generally does not, by itself, create a new right to reconsideration if you are already paying the penalty.[4]

The review is done by an independent review entity under contract with Medicare, not by the plan that billed you. CMS says that entity generally notifies you of the decision within 90 calendar days.[14] You must continue to pay the penalty with your premium while you wait. If the reviewer finds the penalty was wrong, the plan should remove or adjust it and explain any refund.[4] If the reviewer finds it was correct, you keep paying it.

Our team can help you gather the coverage history and notices. We cannot overturn a federal determination. We can help you see whether the uncovered months the plan counted match the coverage you actually had. Name the drug coverage you have today and get it in writing. If you are still working, confirm creditable status before you add Part D, and ask whether dependents would lose coverage if you enroll.[3][15] If a job, COBRA, or retiree drug plan is ending, count two months, not eight.

Practical takeaways

• The Medicare Part D late enrollment penalty is 1% of the national base beneficiary premium for each full month without Part D or creditable drug coverage after your Initial Enrollment Period, rounded to the nearest $0.10 and added to your monthly premium for as long as you have Medicare drug coverage.[1][2][4]
• In 2026 the national base is $38.99. Medicare's 14-month example is a $5.50 monthly add-on. A 17-month example in the same year's fact sheet is $6.60 a month.[1][4][6]
• The trigger is a continuous gap of 63 days or more, not a full 12-month block. That is a different clock from the Part B late-enrollment rule.[1][7]
• Creditable coverage from a current or former employer or union, VA, TRICARE, or Indian Health Service can let you delay Part D without a penalty. Your plan must tell you in writing. Keep those letters.[3][5][15]
• Discount cards, samples, free clinics, and drug-discount websites are not creditable coverage.[3]
• Join during your seven-month Initial Enrollment Period if you do not have creditable drug coverage. If you lose creditable coverage later, you generally have two full months after the month it ends (or after you are notified it is no longer creditable) to join a drug plan or an Advantage plan with drugs.[9][10]
• After you enroll, return any creditable-coverage form the plan sends. If a penalty is assessed and you disagree, request reconsideration within 60 days and keep paying the premium while you wait.[4][14]
• Call SHIIP at 1-855-408-1212 for free, unbiased counseling in every North Carolina county.[11][12]

How we can help

Have more questions or want to get in touch? Visit https://thesih.com/contact/ or call Seniors Insurance Hub at (336) 937-7501. We are an independent Medicare and senior insurance advisory serving Greensboro and the Piedmont. Bring any employer, union, VA, or TRICARE drug-coverage notices you have, plus the dates a job or plan ended. Our team will help you see whether you are still in an enrollment window and how a Part D or Advantage plan would sit next to the coverage you already have.

Citations

1. Medicare.gov, "Avoid late enrollment penalties" (2026)
2. Medicare.gov, "How much does Medicare drug coverage cost?" (2026)
3. Medicare.gov, "Creditable prescription drug coverage" (2026)
4. Medicare.gov, "The Part D Late Enrollment Penalty" (CMS Product No. 11222, July 2026)
5. Centers for Medicare & Medicaid Services, "Creditable Coverage and Late Enrollment Penalty" (2025-07-24)
6. Centers for Medicare & Medicaid Services, "2026 Medicare Part D Bid Information and Part D Premium Stabilization Demonstration Parameters" (2025-07-28)
7. Legal Information Institute, Cornell Law School, "42 CFR § 423.46 Late enrollment penalty" (e-CFR)
8. Legal Information Institute, Cornell Law School, "42 CFR § 423.56 Procedures to determine and document creditable status of prescription drug coverage" (e-CFR)
9. Medicare.gov, "Special Enrollment Periods" (2026)
10. Medicare.gov, "Joining a plan" (2026)
11. N.C. Department of Insurance, "Medicare Prescription Drug Plan (Part D)" (2026)
12. N.C. Department of Insurance, Seniors' Health Insurance Information Program (SHIIP), "Contact Seniors' Health Insurance Information Program (SHIIP)" (2026)
13. Medicare.gov, "Working past 65" (2026)
14. Centers for Medicare & Medicaid Services, "Late Enrollment Penalty (LEP) Appeals" (2024-09-10)
15. Centers for Medicare & Medicaid Services, "Creditable Coverage" (2024-09-10)
16. KFF, "A Current Snapshot of the Medicare Part D Prescription Drug Benefit" (2025-10-07)