Calculator · CY2026 figures

Part B Late Enrollment Penalty Calculator

Enter a date of birth and the month they sign up. We work out the Initial Enrollment Period, the months that count, and what the penalty costs on the 2026 premium: monthly, yearly, and over a lifetime.

What it answers

The months that count: from the end of the Initial Enrollment Period to the end of the month they sign up
Months with job-based coverage taken out, and the full 12-month periods that set the percentage
The penalty in dollars on the 2026 standard premium of $202.90, rounded as Medicare rounds it
When the next 10% lands if they wait, and the penalty’s end at 65 for someone on Medicare through disability

For example: 57 uncovered months → 40%, $81.20 a month for as long as they have Part B.

How it's worked out

10% of the standard premium for each full 12 months they could have had Part B and didn’t. For anyone enrolling since January 1, 2023, the months run to the end of the month they enroll.

Months covered by a group health plan from their own or a spouse’s current job don’t count. COBRA and retiree months do.

The premium with the penalty is rounded to the nearest 10 cents. The lifetime figure assumes today’s premium and coverage to age 85, though the penalty rises whenever the premium does.

Sources

Free tools for licensed insurance agents. Not for use by Medicare beneficiaries. Figures are CMS’s published amounts; Social Security, CMS and the plan make the final determination.

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