Part B Late Enrollment Penalty Calculator
If you didn't sign up for Medicare Part B when you were first eligible, you may pay a higher premium for as long as you have Part B.
Count the number of full months between when you were first eligible for Part B and when you actually enrolled. Do not count months where you had coverage through an employer or union.
Who Pays the Part B Penalty?
You may owe a penalty if you didn't sign up for Part B during your Initial Enrollment Period (the 7-month window around your 65th birthday) and you didn't have qualifying employer or union coverage.
If you had employer coverage through your own job (or your spouse's) and enrolled in Part B within 8 months of that coverage ending, you do not owe a penalty. This is called a Special Enrollment Period (SEP).
How Is the Penalty Calculated?
The penalty is 10% of the standard Part B premium for each full 12-month period you could have had Part B but didn't sign up. For example, if you waited 2 full years, your penalty would be 20% of the standard premium — added to your bill every month, permanently.
Can You Avoid the Penalty?
If you're still working and have employer coverage (for employers with 20+ employees), you can delay Part B without a penalty. When that coverage ends, you have 8 months to enroll penalty-no-cost through a Special Enrollment Period.
*Disclaimer: This calculator provides estimates based on 2026 figures. The standard Part B premium for 2026 is $202.90/month. Actual penalties may vary. This tool is for educational purposes only. (334) 489-3624