Medicare Late Enrollment Penalty Calculators
Delaying enrollment without qualifying coverage can mean permanent penalties on your monthly premiums — for life. Use these calculators to see the impact.
Part B Late Enrollment Penalty
10% surcharge for every full 12-month period you delayed Part B without qualifying employer coverage. Permanent.
Total months without Part B after your IEP, excluding qualifying employer group coverage.
Part D Late Enrollment Penalty
1% of the national base premium per uncovered month if you go 63+ days without creditable drug coverage. Permanent.
Months without Part D or creditable drug coverage after your initial period.
How to Avoid Medicare Penalties
Part B: Enroll during your IEP around age 65, or have qualifying employer group coverage (not COBRA, not Marketplace).
Part D: Enroll when first eligible or maintain creditable drug coverage (employer, VA, TRICARE). Get a creditable coverage letter.
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Written and reviewed by Darin Weidauer — licensed Colorado insurance agent (NPN 18580338), Gerontologist (USC Davis School of Gerontology), MBA, Registered Social Security Analyst, and U.S. Air Force veteran. Independent and appointed with 10 Colorado carriers.Last reviewed September 2, 2026. Plan availability, benefits and costs change every plan year — verify current details at Medicare.gov or 1-800-MEDICARE.