Medicare Part D Late Enrollment Penalty Calculator
If you went without Medicare drug coverage when you were first eligible, Medicare can add a permanent surcharge to your monthly premium. Use the calculator below to estimate what that surcharge will be in 2026, then read on for how it works and whether it can be appealed.
Reflects the 2026 national base beneficiary premium of $38.99, announced by CMS on July 28, 2025. Reviewed by the licensed agents at Waugh Agency.
Estimate your penalty
Three quick questions. Nothing is submitted and no information leaves this page unless you choose to email yourself the result.
Want this estimate in writing? Optional — we will send it over and a licensed agent will review whether the penalty can be appealed.
Estimate only. Your plan, working with CMS, determines the final penalty amount. Based on the 2026 national base beneficiary premium of $38.99, which changes annually.
What the Part D late enrollment penalty actually is
The Part D late enrollment penalty — the LEP — is a permanent surcharge added to your monthly Medicare drug plan premium. It is not a one-time fine and it is not a bill you can settle. Once it is assessed, it rides along with your premium for as long as you have Medicare drug coverage, including if you switch plans or move to a different state.
You can be assessed the penalty in two situations:
- You did not join a Medicare drug plan when you were first eligible, and you did not have other creditable drug coverage.
- At any point after your Initial Enrollment Period ended, you went 63 days or more in a row without Part D or other creditable drug coverage.
That 63-day threshold matters. A short gap — changing jobs, a plan termination that gets fixed the following month — generally does not trigger anything. Two full months is usually safe. Three is not.
How CMS calculates the penalty in 2026
The formula has three moving parts:
- Count the uncovered months. Every full month after your Initial Enrollment Period ended during which you had neither Part D nor creditable drug coverage.
- Multiply by 1% per month. Twelve uncovered months is a 12% penalty, twenty-four months is 24%, and so on. There is no cap.
- Apply that percentage to the national base beneficiary premium. For 2026 that figure is $38.99. The result is rounded to the nearest ten cents and added to your monthly premium.
Worked example
A client turned 65 in June 2024 and did not enroll in a drug plan because she was not taking any prescriptions. Her Initial Enrollment Period closed at the end of September 2024. She finally enrolled during Open Enrollment, with coverage effective January 1, 2026.
October 2024 through December 2025 = 15 uncovered months
15 × 1% = 15% penalty rate
15% × $38.99 = $5.85, rounded to the nearest $0.10 = $5.80 per month
That is $69.60 a year, every year, on top of whatever her plan charges. And because the national base beneficiary premium rises most years, her dollar penalty rises with it — the 15% is locked in, but the number it is applied to is not.
What the penalty costs at different gap lengths
All figures use the 2026 national base beneficiary premium of $38.99. The ten-year column assumes the premium stays flat, which it will not — treat it as a floor, not a ceiling.
| Months without coverage | Penalty rate | Added per month | Added per year | Over 10 years |
|---|---|---|---|---|
| 3 months | 3% | $1.20 | $14.40 | $144 |
| 6 months | 6% | $2.30 | $27.60 | $276 |
| 1 year | 12% | $4.70 | $56.40 | $564 |
| 2 years | 24% | $9.40 | $112.80 | $1,128 |
| 3 years | 36% | $14.00 | $168.00 | $1,680 |
| 5 years | 60% | $23.40 | $280.80 | $2,808 |
| 7 years | 84% | $32.80 | $393.60 | $3,936 |
| 10 years | 120% | $46.80 | $561.60 | $5,616 |
The ten-year row is the one that surprises people. Someone who skipped drug coverage from 65 to 75 because they took no medications pays more in penalty than many plans charge in premium.
What counts as creditable drug coverage
Creditable coverage is drug coverage that Medicare considers at least as good as standard Part D. Months you spend under creditable coverage do not count toward the penalty. Plan sponsors are required to send you a notice each fall telling you whether your coverage is creditable — that notice is the document you want in a folder somewhere.
Usually creditable
- Most employer and union group health plans
- Retiree drug coverage from a former employer
- COBRA, if the underlying plan was creditable
- VA prescription benefits
- TRICARE and TRICARE for Life
- Federal Employees Health Benefits (FEHB)
- Indian Health Service coverage
- Some state pharmaceutical assistance programs
Not creditable
- Pharmacy discount cards and coupon programs
- Manufacturer patient assistance programs
- Health care sharing ministries
- Most short-term medical plans
- Employer plans that specifically state they are non-creditable
- Having no prescriptions to fill (this is not coverage)
Four ways to avoid the penalty entirely
- Enroll during your Initial Enrollment Period. Seven months total: the three months before your 65th birthday month, that month, and the three months after. Even if you take no medications, a low-premium plan keeps the clock from ever starting.
- Keep creditable coverage and document it. If you are still working and your group plan is creditable, you can delay Part D indefinitely. Save the annual notice.
- Use your Special Enrollment Period on time. When creditable coverage ends, you generally have a two-month window to pick up Part D without penalty. Missing it is what converts a clean situation into a permanent surcharge.
- Check whether you qualify for Extra Help. Beneficiaries who receive the Part D Low Income Subsidy do not pay the late enrollment penalty at all, and any existing penalty stops while they are enrolled.
How you will find out that you owe it
You will not hear about the penalty from Medicare directly. After you join a drug plan, the plan checks your coverage history with CMS and mails you a letter stating the penalty amount and the months CMS believes you were uncovered. The surcharge then shows up on your premium bill.
Read that letter carefully and check the months against your own records. CMS is working from data that plan sponsors reported, and it is not always complete — coverage through a small employer or a plan that has since terminated is the most common thing to go missing.
How to appeal the penalty
You have the right to a reconsideration, and it is worth pursuing when the record is wrong. Appeals are handled by C2C Innovative Solutions, the independent review entity CMS contracts with for Part D LEP cases.
- Deadline: 60 days from the date on the letter telling you about the penalty. Miss it and you can still file, but you must attach a written good-cause explanation.
- Form: the Part D LEP Reconsideration Request Form, which your plan will include with the notice.
- Evidence: proof of creditable coverage for the disputed months. Creditable coverage notices, a letter from a former employer or plan administrator, enrollment records, or VA/TRICARE documentation.
- Timeline: C2C generally issues a decision within 90 days.
Appeals that succeed almost always come down to documentation, not argument. Not knowing about the penalty is not grounds for reversal; proving you actually had coverage during the months in question is. Waugh Agency handles these reconsiderations for our clients and works directly with the carriers we represent to reconstruct the coverage record.
2026 Part D figures worth knowing
| National base beneficiary premium | $38.99/month |
|---|---|
| Late enrollment penalty rate | 1% per uncovered month (12% per year) |
| Maximum Part D deductible | $615 |
| Out-of-pocket cap on covered drugs | $2,100 |
| Standard Part B premium | $202.90/month |
| Gap that triggers the penalty | 63 days or more in a row |
For context on the trend: the national base beneficiary premium was $32.74 in 2023, $34.70 in 2024, $36.78 in 2025, and $38.99 in 2026 — a 19% climb in three years, held to 6% annually by the Inflation Reduction Act's premium stabilization cap through 2029. Your penalty percentage is fixed; the dollars behind it are not.
Questions we get most
Does the penalty ever go away?
For most people, no. It applies for as long as you have Medicare drug coverage. There are two exceptions: if you qualify for Extra Help, the penalty is waived while you are enrolled; and if you successfully appeal, it is removed retroactively and you are refunded.
I take no prescriptions. Do I still need Part D?
Taking no medications does not exempt you. The penalty clock runs on whether you had coverage, not whether you used it. Enrolling in a low-premium plan at 65 typically costs far less than the surcharge you would owe later, and it protects you if your health changes.
I am still working at 65 with employer coverage. Do I need to enroll?
Not if your employer drug coverage is creditable. Get that confirmation from HR in writing and keep it. When you retire or the coverage ends, you have a two-month Special Enrollment Period to pick up Part D without penalty.
Does the penalty apply to Medicare Advantage plans too?
Yes, if the Medicare Advantage plan includes drug coverage. The penalty attaches to the drug portion of the premium and follows you between plan types.
What if I switch drug plans — does the penalty reset?
No. The percentage travels with you. Switching plans changes your base premium but not the surcharge on top of it.
Can my spouse's coverage protect me?
Only if you are actually enrolled in it and it is creditable. Being married to someone with creditable coverage does nothing on its own.
Is this calculator's number final?
No. It is an estimate based on the dates you enter and the 2026 national base beneficiary premium. Your plan, working with CMS, determines the official amount using the coverage history on file. If the two do not match, that discrepancy is exactly what an appeal is for.
Talk to a licensed agent
Waugh Agency has been placing Medicare coverage in Massachusetts and beyond since 1998. We will confirm whether you actually owe a penalty, look at whether it can be appealed, and find you the most affordable drug plan for the medications you take. There is no charge for the review.
Local: (617) 821-2273 · Monday–Friday 8:30 AM–7:00 PM, Saturday 10:00 AM–4:00 PM
This page is for general education and is accurate as of July 2026. Figures come from the Centers for Medicare & Medicaid Services. Waugh Agency, LLC is a licensed insurance agency, not a government agency, and is not affiliated with or endorsed by Medicare or CMS. We do not offer every plan available in your area. Any information we provide is limited to the plans we do offer. Please contact Medicare.gov, 1‑800‑MEDICARE, or your local State Health Insurance Assistance Program (SHIP) to get information on all of your options.