If you don’t sign up for Medicare Part B when you’re first eligible and don’t qualify for a Special Enrollment Period, you may have to pay a late enrollment penalty. This penalty is added to your monthly Part B premium and lasts for as long as you have Part B.
The penalty is 10 percent for each full 12-month period you delayed enrollment without other creditable coverage. It’s a lifetime penalty, so it can add up quickly.
In 2026, the standard monthly Part B premium is $202.90. If you delayed enrollment by one full year, your premium would increase by 10 percent, or $20.29. That means your new monthly premium would be $223.19 for 2026. If you delayed by two years, your penalty would be 20 percent, bringing your monthly premium to $243.48.
The longer you wait, the higher the penalty. To avoid it, sign up when you’re first eligible or during a Special Enrollment Period if you have coverage through an employer or union. If you’re unsure whether your current coverage qualifies as creditable, check with your employer or plan administrator before your initial enrollment period ends.