What Is the Medicare Part B Late Enrollment Penalty?

How the Part B Penalty Works

Medicare.gov describes a late enrollment penalty as an extra amount added to your monthly premium when you do not sign up during your Initial Enrollment Period and you do not have other coverage that is similar in value to Medicare, such as coverage from an employer. Illinois residents are subject to the same federal rules as people in every other state.

For Part B, the penalty is an extra 10% for each year you could have signed up but did not. More precisely, Medicare.gov counts each full 12-month period. If you waited two full years, or 24 months, to sign up for Part B and did not qualify for a Special Enrollment Period, the penalty would be 20%: 10% for each full 12-month period that you could have signed up. That percentage is applied to the standard Part B premium.

Two details are worth noticing. First, partial years are not counted, because the calculation uses full 12-month periods. Second, the longer you go without coverage that is similar to Medicare, the larger the percentage becomes.

Why It Is Not a One-Time Fee

The most surprising part for many people is how long the penalty lasts. Medicare.gov says late enrollment penalties:

• Are added to your monthly premium.
• Are not a one-time late fee.
• Are usually charged for as long as you have that type of coverage, which for most people means a lifetime penalty.
• Go up the longer you wait, because they are based on how long you go without coverage similar to Medicare.

Medicare.gov also notes that you may pay a higher premium depending on your income. That income-related adjustment is separate from the late enrollment penalty, so a person could be affected by both.

Ways People Avoid the Penalty

Generally, you will not have to pay a Part B penalty if you qualify for a Special Enrollment Period or you enroll in a Medicare Savings Program, according to Medicare.gov. The most familiar Special Enrollment Period involves health coverage through your own current job or your spouse's current job. In that situation, you can generally sign up for Part B later without a penalty, within a limited window after the job or the group coverage ends.

Not every kind of coverage qualifies. Medicare.gov lists COBRA and retiree coverage as situations that do not create a Special Enrollment Period. That distinction catches people off guard, so it is worth confirming what type of coverage you have before you decide to delay Part B.

If you do miss your window and no exception applies, you may be able to sign up during the General Enrollment Period, which runs from January 1 through March 31 each year. Coverage then starts the month after you sign up, and the penalty may still apply.

How the Part A and Part D Penalties Differ

Part B is not the only part with a penalty, and the rules are not the same for each.

Most people do not pay a premium for Part A, so the penalty rarely comes up. Medicare.gov explains that if you have to buy Part A and do not buy it when you are first eligible, your monthly premium may go up 10%, and you pay that higher premium for twice the number of years you did not sign up. For example, if you were eligible for two years but did not sign up, the higher premium lasts four years.

The Part D prescription drug penalty is calculated differently. Medicare.gov says you may pay an extra 1% for each month, which is 12% a year, if you do not join a drug plan when you first get Medicare and then go 63 days or more without creditable drug coverage. You generally will not owe this penalty if you have creditable drug coverage, which is coverage expected to pay, on average, at least as much as Medicare drug coverage, or if you qualify for Extra Help. Unlike the Part A penalty, the Part D penalty is added for as long as you have Medicare drug coverage, even if you switch plans.

A Quick Planning Checklist

Before your Initial Enrollment Period ends, it helps to confirm three things: what coverage you will have when you turn 65, whether it counts as coverage similar to Medicare, and which sign-up dates apply to you. Medicare.gov and the Social Security Administration can confirm the details for your own situation.

This guide is educational and is not an offer of insurance.