Lifestyle

Signing Up Late for Medicare Part B Can Mean a Penalty That Lasts for Life. Who Can Avoid It

By Erica Coleman · October 30, 2026

Many people approaching 65 know they should sign up for Medicare but are less sure about the timing for Part B. Missing the window can cost money every month for years, and the penalty does not go away once you enroll.

Medicare says late enrollment penalties are added to your monthly premium, are not a one-time late fee and are usually charged for as long as you have that type of coverage. “For most people, that’s a lifetime penalty,” the agency says.

Here is how the Part B rule works and who can delay signing up without paying it.

The first window. For most people, the Initial Enrollment Period lasts seven months, starting three months before the month you turn 65 and ending three months after it, according to Medicare.gov. If you miss it and do not qualify for a Special Enrollment Period, you generally have to wait for the General Enrollment Period, which runs from January 1 to March 31 each year, with coverage starting the month after you sign up.

How the penalty is figured. Medicare says you pay an extra 10% for each full 12-month period you could have signed up for Part B but did not. In the agency’s example, someone who waited two full years would pay a 20% penalty on top of the standard Part B premium, which Medicare lists as $202.90 a month in 2026, for a total of $243.50 a month. Social Security’s program operations manual says that when the premium rises, the penalty percentage stays the same but the dollar amount of the surcharge grows with it.

The main exception is job coverage. Medicare.gov says people who have health insurance through their own job or a spouse’s job can sign up for Part B later during a Special Enrollment Period. The Social Security Administration, which handles Part B sign-ups, says you can delay Part B if you’re already covered through an employer group health plan. Medicare’s sign-up guide asks whether you or your spouse are still working for the employer that provides the coverage and whether that employer has 20 or more employees. If the company has fewer than 20 employees, Medicare says your job-based coverage might not pay for services if you don’t have both Part A and Part B, so check with the employer.

The eight-month clock. This Special Enrollment Period ends eight months after the group health plan coverage or the employment ends, whichever happens first. Medicare says the clock starts when you stop working even if you choose COBRA, and that COBRA is not considered group health plan coverage. When signing up, you will need to fill out an extra form showing you had job-based coverage while you or your spouse were working.

What does not count. Medicare.gov lists situations that do not qualify for a Special Enrollment Period, including the end of COBRA or retiree coverage, missing the eight-month window after you stopped working or lost job-based coverage, and having or losing Marketplace coverage.

Other ways out. Medicare says you generally will not pay a Part B penalty if you enroll in a Medicare Savings Program. Special Enrollment Periods also exist for some people who lost Medicaid, were affected by a declared disaster or received inaccurate information from their health plan or employer.

To avoid a gap, Medicare suggests that people who want coverage to begin when their job-based insurance ends sign up for Part B the month before they or their spouse retire.

This article is for general information and is not financial or legal advice. Rules can depend on your situation, so check with Medicare or Social Security before making enrollment decisions. This article was produced with the assistance of AI and fact-checked against the sources cited by LightWave Reports.