Medicare Part B Late Enrollment Penalty and General Enrollment Period
The penalty generally adds 10% for each full 12-month period you could have had Part B but did not, and it usually lasts as long as you have Part B.
Your monthly Part B premium generally increases by 10% for each full 12-month period you could have had Part B but did not enroll. The penalty normally continues for as long as you have Part B.
Social Security determines the penalty using your actual eligibility and coverage history. A Special Enrollment Period or enrollment in a Medicare Savings Program can prevent the penalty in qualifying situations.
Count Full Twelve-Month Periods
12 full months late
The penalty is generally 10% of the standard Part B premium.
24 full months late
The penalty is generally 20% of the standard Part B premium.
Because the standard Part B premium can change each year, the dollar amount of a percentage penalty can also change.
The late-enrollment penalty reflects delayed enrollment. IRMAA is an income-related surcharge. A person can owe one, both or neither.
January 1 Through March 31
If you missed the Initial Enrollment Period and do not qualify for an SEP, the General Enrollment Period is available each year from January 1 through March 31. Under current rules, coverage generally begins the first day of the month after you enroll.
Using the GEP does not erase a penalty. It provides an enrollment opportunity after the earlier window was missed.
Check Whether Another Enrollment Right Applies
Current-employment SEP
Qualifying group coverage based on current employment may protect the delay.
Review the working-aged SEP →Exceptional-circumstance SEP
Special rules can apply after disasters, misinformation, incarceration, Medicaid loss or other qualifying circumstances.
Medicare Savings Program
Enrollment in an MSP may prevent a Part B penalty. State eligibility rules apply.
Incorrect record
Preserve employer coverage evidence and contact Social Security if the enrollment history is wrong.
Do Not Rely on Coverage That Does Not Protect Part B
COBRA, retiree coverage, Marketplace insurance, VA benefits and individual insurance do not generally create the working-aged Part B SEP. The safe approach is to confirm the rule before the Initial Enrollment Period or active-employment coverage ends.
Use When Should You Sign Up for Medicare? for the complete enrollment map.
Frequently Asked Questions
How much is the Part B late enrollment penalty?
Generally 10% of the standard Part B premium for each full 12-month period you could have had Part B but did not.
Does the Part B penalty ever end?
It normally continues for as long as you have Part B, unless a specific exception or correction applies.
When is the General Enrollment Period?
January 1 through March 31 each year. Coverage generally begins the first day of the following month.
Does enrolling during the GEP remove the penalty?
No. The GEP allows enrollment but does not erase a penalty that otherwise applies.
Can employer coverage prevent the penalty?
Qualifying group coverage based on current employment can support a Part B SEP. Social Security decides based on the evidence.
Sources and Enrollment Resources
Check the Enrollment Record Before Assuming the Penalty Is Correct
We can help you organize the coverage history and private-plan timeline, while Social Security makes the official penalty and enrollment decision.
Thompson Medicare Brokerage is not connected with or endorsed by the U.S. government or the federal Medicare program. This page provides general educational information. Social Security or the Railroad Retirement Board makes official Medicare Parts A and B enrollment, effective-date and penalty decisions. Employer, Marketplace and tax consequences depend on individual circumstances.