Part D · 2026
Part D late enrollment penalty calculator
See how a gap in creditable drug coverage changes the monthly Part D penalty, then check the notice and dates that can remove it.
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Written and maintained by Daniel SmithCalifornia, USA
| Penalty rate | 1% per monthApplied to the national base beneficiary premium, not your plan premium. |
|---|---|
| Base beneficiary premium, 2026 | $38.99The national reference amount for the penalty. |
| One-year penalty | $4.70/monthAdds $56.40 a year. |
| Penalty trigger | 63 days or moreGenerally a continuous gap in creditable drug coverage. |
| How long it lasts | Generally permanentIt continues while you have Part D, unless Medicare corrects it. |
| Creditable coverage | Written notice requiredThe plan decides and must tell you in writing. |
Your result
Part D penalty estimate
Enter the months without creditable drug coverage to see the result.
Enter the months without creditable drug coverage
The calculator needs a whole number of months. A written creditable coverage notice can change whether those months count.
What is the Part D late enrollment penalty
The Part D late enrollment penalty is a permanent surcharge added to your monthly drug plan premium when you go without creditable prescription drug coverage for too long. The surcharge is based on the national base beneficiary premium, not on the premium of the plan you choose.
Because the base premium changes each year, the dollar penalty can change too even if your gap does not. The penalty is separate from the Part B late enrollment penalty and from the Part D IRMAA surcharge.
How is Part D penalty calculated
Medicare multiplies 1% of the national base beneficiary premium by each full month without creditable coverage, then rounds the monthly penalty to the nearest 10 cents.
The count uses full months. A gap of a few days inside a month does not add a month by itself, but the continuous gap still has to be checked against the 63-day trigger. Keep the exact coverage dates from the plan.
Part D penalty 2026 per month
At the 2026 base premium, one uncovered month adds $0.40 a month. Twelve uncovered months add $4.70 a month, or $56.40 a year. Twenty-four uncovered months add $9.40 a month.
These amounts are the penalty only. Your actual Part D bill also includes the plan premium, and it can include an IRMAA surcharge if your income is above the IRMAA threshold.
Can Part D penalty be waived
The penalty is not waived just because you did not know the rule. It can be corrected if the records show creditable coverage for the gap, or if the plan or Medicare made an enrollment error. Start with the plan’s written creditable coverage notice and the exact dates.
Contact Medicare and the plan and ask which months were counted. If the notice covers the gap, ask for a review. Keep copies of the notice, the letters, and anything you send.
What counts as creditable drug coverage
Creditable coverage is drug coverage that the plan expects to pay, on average, at least as much as standard Part D coverage. Employer retiree coverage, some union plans, and certain other drug plans may qualify. The plan must tell you in writing each year whether its coverage is creditable.
Medicare Advantage plans with drug coverage and standalone Part D plans count as Part D coverage while they are in force. Dropping that coverage and going without creditable drug coverage can start penalty months.
What to do next
- Find the date your Part D coverage started and the date the prior coverage ended. Confirm both with the plan and with Medicare.gov’s Part D cost page.
- If you get Extra Help, ask how it applies to the plan premium. Start with Social Security’s Extra Help page.
- Read the current national base beneficiary premium and plan parameters in the CMS Part D premium parameters.
- Keep the plan notices and premium records with your tax papers. Part D premiums can count toward medical expenses; see IRS Publication 502.
What changed for 2026 compared with 2025
| Rule | 2025 | 2026 |
|---|---|---|
| National base beneficiary premiumThe penalty is calculated from this amount. | $36.78 | $38.99 |
| Penalty after 12 uncovered months1% per month, rounded to the nearest 10 cents. | $4.40 | $4.70 |
| Part D deductibleNot part of the penalty, but part of the drug cost picture. | $590.00 | $615.00 |
| Part D out-of-pocket capThe cap does not remove the late enrollment penalty. | $2,000.00 | $2,100.00 |
Worked examples
The first example uses 12 full uncovered months. The second adds a plan premium equal to the national base premium so you can see how the penalty sits beside a plan bill. The third shows a gap shorter than 63 days.
| Input or result | 12-month gap | 24-month gap | Short gap |
|---|---|---|---|
| Full uncovered months | 12 | 24 | 2 |
| Months counted | 12 | 24 | 0 |
| Penalty rate | 12% | 24% | 0% |
| Monthly penalty | $4.70 | $9.40 | $0.00 |
| Annual penalty | $56.40 | $112.80 | $0.00 |
| Plan premium plus penalty | Enter your plan premium | $48.39 | Not applicable |
| 10-year penalty total | $564.00 | $1,128.00 | $0.00 |
The 24-month example assumes a plan premium of $38.99, the same as the national base premium. Your plan premium is different and is not stored or guessed by this page.
MedicareClear is independent. We do not sell plans, rank carriers, or claim an official connection to Medicare.gov or any government agency.
Three honest caveats
- The official penalty uses Social Security and plan enrollment records. This page uses the months you enter, so check the exact dates before you rely on the number.
- A plan premium is not a fixed national number. The calculator keeps the penalty and the optional plan premium separate so a plan change does not look like a penalty change.
- A review can correct a penalty, but it does not stop the plan from billing it while the review is pending. Ask the plan what it expects you to pay in the meantime.
Frequently asked questions
Can Part D penalty be waived?
Not automatically. Medicare may correct or remove the penalty if its records or the plan’s written notice show creditable drug coverage for the gap. Ask the plan for the notice, then contact Medicare and the plan for a review. Not knowing the rule is not usually a reason to remove the penalty.
What are creditable drug coverage gap days?
The penalty is built from full uncovered months, and the trigger is generally a continuous gap of 63 days or more after your initial enrollment period. A shorter continuous gap does not usually start a Part D penalty. Keep the exact start and end dates because the plan and Medicare use their records, not a rounded memory.
How is the Part D penalty calculated?
Medicare multiplies 1% of the national base beneficiary premium by the number of full months without creditable coverage. It then rounds the monthly amount to the nearest 10 cents. At the current base premium, 12 uncovered months add the amount shown in the calculator.
What is the Part D penalty for 2026 per month?
At the 2026 national base beneficiary premium of $38.99, one uncovered month adds about $0.40 a month. Twelve uncovered months add about $4.70 a month.
Does the Part D penalty go away if I switch plans?
No. The penalty generally follows you between Part D plans because it is based on the national base beneficiary premium, not the plan’s own premium. Changing plans can change the plan premium, but it usually does not remove a valid late enrollment penalty.
What counts as creditable drug coverage?
Creditable coverage is prescription drug coverage the plan expects to pay, on average, at least as much as standard Part D coverage. Employer retiree coverage, some union plans, and certain other drug plans may qualify. The plan must tell you in writing each year whether its coverage is creditable.
How do I ask for a Part D penalty review?
Gather the plan’s written creditable coverage notice, your Part D enrollment dates, and any letters about the penalty. Contact Medicare and the plan and ask which months were counted. If the notice covers the gap, ask for the penalty to be corrected and keep a copy of everything you send.
Does Extra Help pay the Part D late enrollment penalty?
Extra Help can lower Part D premiums and cost sharing, but it does not automatically erase a late enrollment penalty. Ask Social Security and the plan how Extra Help applies to your specific premium and whether any penalty review is pending.
Related help
Source table
| Figure | Value used | Official source |
|---|---|---|
| Part D penalty rate | 1% per full uncovered month | Medicare.gov Part D costsChecked |
| National base beneficiary premium | $38.99 | CMS Part D premium parametersChecked |
| Penalty trigger | Continuous gap of 63 days or more | Medicare.gov late enrollment penaltiesChecked |
| Creditable coverage | Written notice from the plan | Medicare.gov Part D costsChecked |
| Annual enrollment period | October 15 through December 7 each year | Medicare.gov sign-up rulesChecked |
Cite this page
If you cite this page, use the reference below. It shows the date the figures were last checked so readers can judge whether they are current.
MedicareClear. “Part D late enrollment penalty calculator.” Figures checked October 28, 2026. https://medicareclear.top/calculators/part-d-late-enrollment-penalty/
Print the checklist for a parent or keep a copy for your records. If a figure looks wrong, send the page and the official source you used.
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MedicareClear is independent and is not connected to Medicare.gov, Social Security, or any government agency. This page is educational and does not provide legal, tax, or insurance advice. Confirm your enrollment dates and coverage with Medicare or the plan before you act.
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