Medicare late enrollment penalty calculator.
If you delay Medicare without creditable coverage, you'll pay a penalty added to your premium every month for the rest of your life. Calculate yours below — for both Part B and Part D.
Part B late enrollment penalty
10% of the standard Part B premium for each full 12-month period you delayed Part B without creditable coverage. Lifetime — for as long as you have Part B.
Part D late enrollment penalty
1% of the national base Part D premium ($36.78 in 2026) for each month you went without creditable drug coverage after your Initial Enrollment Period ended. Lifetime — for as long as you have Part D.
How the Part B late enrollment penalty works
The Part B penalty is calculated as 10% of the standard Part B premium for each full 12-month period you could have had Part B but didn't enroll. The standard Part B premium in 2026 is $185.00/month.
Important nuances:
- Only "full 12-month periods" count. An 18-month delay = 1 full year, not 1.5. (You'd pay 10%, not 15%.)
- The penalty grows as the standard premium grows. If Part B premium goes up to $200 in 2030, your 10% penalty becomes $20/month instead of $18.50.
- Creditable coverage gaps don't count. If you had employer coverage from age 65 to 67, then went 8 months uncovered before enrolling — only the 8 months count, but since 8 < 12, the penalty is $0.
- The penalty is lifelong. It doesn't go away. Even if you switch Medicare Advantage plans, switch Medigap plans, or change anything else, the penalty stays.
How the Part D late enrollment penalty works
The Part D penalty is calculated as 1% of the national base Part D premium for each month you went without creditable prescription drug coverage after your Initial Enrollment Period ended. The 2026 national base premium is $36.78/month.
Important nuances:
- Counted in months, not years. A 30-month gap = 30%, not 2-and-a-half years.
- The penalty floats with the national base premium. Each year the base premium changes, your penalty recalculates as that percentage.
- Added to whatever Part D plan you choose. The penalty is on top of your plan's regular premium.
- Lifelong. As long as you have Part D, you pay the penalty.
- Extra Help / Low Income Subsidy waives it. If you qualify for Extra Help, the penalty is automatically waived as long as you stay qualified.
Real-world penalty examples
How to avoid the penalty entirely
- Enroll during your Initial Enrollment Period (IEP) — the 7-month window starting 3 months before your 65th birthday month and ending 3 months after. No penalty if you enroll then.
- Have creditable coverage during the delay. Employer group health plans (yours or your spouse's, with 20+ employees), TRICARE for Life, VA coverage, and federal employee health benefits all count. Get a "creditable coverage notice" from your employer in writing.
- Use your Special Enrollment Period (SEP) when creditable coverage ends. You have 8 months to enroll in Part B and 63 days to enroll in Part D after your creditable coverage ends — penalty-free.
- Watch out for COBRA and retiree coverage. COBRA does NOT count as creditable coverage for Part B in most cases. Retiree health coverage may or may not — get it in writing.
Already paying a penalty?
In limited circumstances, the penalty can be appealed and removed: (1) you were misinformed by a federal employee or SSA representative, (2) your former employer's coverage was wrongly labeled creditable, or (3) you now qualify for Extra Help (LIS) which waives the Part D penalty automatically. Call us — we can review your situation in 5 minutes.
Need help avoiding or appealing a penalty?
A licensed advisor reviews your enrollment timeline, your coverage history, and any penalty notices — free, in about 14 minutes.
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