Medicare Part B Late-Enrollment Penalty Calculator

The Medicare Part B late-enrollment penalty is permanent. Enter the current standard premium and how many full years you delayed to see the lifetime cost of enrolling late.

Worked Example

Sample input: Standard Part B monthly premium ($, from medicare.gov): 185, Full years you delayed enrolling: 2, Expected years on Medicare: 20

Lifetime penalty cost: 8880 (A costly permanent penalty)

Enrolling 2 full year(s) late adds a permanent 20% surcharge — about $37 extra per month, or roughly $8,880 over 20 years on Medicare. The penalty never goes away, so enroll on time.

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Frequently Asked Questions

How is the Part B late penalty calculated?

The penalty is 10 percent of the standard premium for each full 12-month period you were eligible for Part B but did not enroll. It is added to your monthly premium and lasts as long as you have Part B. Check medicare.gov for the current standard premium.

Is the penalty really permanent?

Yes. Unlike a one-time fee, the Part B late-enrollment penalty is added to your premium for life, so it compounds across all your years on Medicare. That is why enrolling on time matters so much.

When should I enroll to avoid it?

Enroll during your Initial Enrollment Period, the seven-month window around your 65th birthday, unless you have qualifying coverage (such as an active employer plan) that lets you delay. In that case a Special Enrollment Period usually avoids the penalty; verify your situation on medicare.gov.

What if I had employer coverage past 65?

If you (or your spouse) had active employer group coverage, you generally get a Special Enrollment Period to sign up for Part B without penalty after that coverage ends. Retiree coverage and COBRA do not count, so confirm the rules on medicare.gov before delaying.

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