Part A Late Enrollment Penalty

For most people there is no penalty for Medicare Part A, as long as they have worked 10 years (40 quarters) and paid Medicare taxes. While you are not required to sign up for Medicare Part A, if both you and your spouse have worked less than 40 quarters and do not sign up for Medicare Part A during your Initial Enrollment Period, you will have to pay a late enrollment penalty.

The late enrollment penalty is 10 percent of either your $285 or $518 premium in 2025, which is added to the monthly premium. Unlike the Medicare Part B penalty, it doesn’t last forever. Instead, you will pay the Medicare Part A penalty for twice the number of years that you could have paid premiums for Part A but didn’t. For example, if you delayed enrollment for 3 years, you would pay penalties for 6 years. So, if you worked for fewer than 7.5 years (30 quarters), you would have to pay monthly penalty of $51.80 (10 percent of $518.00) for 6 years.

Because Part A premiums usually change each year, your penalty will generally change each year too. Should you have a penalty, the Social Security office will calculate your penalty, if any, accordingly. For people who have to pay a Medicare Part A premium and do not sign up during their Initial Enrollment Period, the only way to not pay a late enrollment penalty is if you have a Special Enrollment Period, such as coming off a group or union health plan if you are still working.

HSA

If you have a Health Savings Account (HSA), you should stop contributions into your HSA 6 months prior to enrolling in Medicare in order to avoid a tax penalty, as making contributions while enrolled in Medicare is not allowed.

Keep in mind if you enroll in Medicare after you are age 65, the effective date of Medicare will be 6 months retroactive back but not earlier than the month you turn 65.

When to Enroll 

Generally speaking, you should sign up for Medicare Part A when you first become eligible because of the risks and possible penalties of signing up later, such as a gap in coverage or having to pay a late enrollment penalty. However, in some cases, it makes sense to sign up later. For instance, when working past age 65 and staying on your group or union health plan.

Part A Premium-Free Enrollment

Initial Enrollment Period. This consists of a 7-month window that begins 3 months before your 65th birthday, the month of your 65th birthday, and 3 months after your 65th birthday. If you enroll during the first 3 months, coverage becomes effective the first day of the month you turn 65. If you enroll during the month you turn 65, or during the 3 months after you turn 65, coverage becomes effective the first of the following  month. 

If you did not sign up for premium-free Part A during your initial enrollment period, you can sign up sign up for premium-free Part A any time after you turn 65. Coverage is always effective 6 months back from the date you sign up but no earlier than the date you turn 65.

Part A Premium Required Enrollment

If you have to pay a premium for Medicare Part A because neither you nor your spouse worked 10 years (40 quarters) and payed Medicare taxes, you can only sign up for Premium-Part A during certain times.

Initial Enrollment Period: This consists of a 7-month window that begins 3 months before your 65th birthday, the month of your 65th birthday, and 3 months after your 65th birthday. If you enroll during the first 3 months, coverage becomes effective the first day of the month you turn 65. If you enroll during the month you turn 65, or during the 3 months after you turn 65, coverage becomes effective the first of the following month. If you sign up during this time, you will not have to pay a late enrollment penalty.

General Enrollment Period: This period runs from January 1^st to March 31^st with coverage being effective the first of the following month that you sign up. If you sign up during this time, you will be required to pay a late enrollment penalty. 

Special Enrollment Period: After your first chance to sign up during your Initial Enrollment Period, there are certain situations when you can sign up for Part A Premium Required without paying a late enrollment penalty. This is called a Special Enrollment Period and is only available for a limited time. Coverage typically becomes effective the first of the month that you sign up.

Examples of Part A Premium Required Special Enrollment periods consist of but not limited to: