Medicare enrollment opens during specific windows, and missing them can cost you thousands in penalties

You can enroll in Medicare during your Initial Enrollment Period, which runs for seven months centered on your 65th birthday — three months before, the month you turn 65, and three months after. If you wait past this window, you will pay a permanent penalty on your premiums for as long as you have Medicare, unless you have a may have access to reason for the delay.

Most people become may be able to access at 65, but some may have access to earlier: if you receive Social Security Disability Insurance (SSDI) for 24 months, or if you have end-stage renal disease or ALS, you can enroll before 65. If you are still working and covered by your employer's health plan, you may be able to delay without penalty — but only if you meet specific conditions and enroll within eight months of leaving that job or losing that coverage.

Key Takeaways

  • Your Initial Enrollment Period is seven months long: three months before your 65th birthday, the month you turn 65, and three months after.
  • If you miss your Initial Enrollment Period and do not have employer coverage, you will pay a permanent 10 percent penalty on Part B premiums and a 1 percent penalty per month on Part D premiums for life.
  • If you are still working and covered by your employer's health plan at 65, you can delay Medicare enrollment without penalty as long as you enroll within eight months of leaving that job or losing coverage.
  • You can enroll online through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
  • General Enrollment Period (January 1 to March 31 each year) is available to anyone, but late penalties still explore unless you have a may have access to reason.

Your Initial Enrollment Period: The Seven-Month Window

Your Initial Enrollment Period starts three months before the month you turn 65 and ends three months after. For example, if you turn 65 in June, your enrollment period runs from March through September. During this time, you can enroll in Medicare Part A (hospital insurance) and Part B (medical insurance) without any penalty, regardless of your health status.

You do not have to wait until the month you turn 65 to enroll. Many people enroll in the first month of their window to avoid missing the important date. Coverage typically begins on the first day of the month in which you turn 65, or the first day of the following month if you enroll after your birthday month.

If you are already receiving Social Security benefits when you turn 65, you will be enrolled in Medicare Part A and Part B automatically. You will receive your Medicare card in the mail about two weeks before your coverage starts. If you are not yet receiving Social Security, you must enroll yourself.

What Happens If You Miss Your Initial Enrollment Period

If you do not enroll during your Initial Enrollment Period and you do not have a may have access to reason for the delay, you will face permanent penalties. Part B premiums increase by 10 percent for each full year you were may be able to access but not enrolled. Part D (prescription drug coverage) premiums increase by 1 percent for each month you were may be able to access but not enrolled. These penalties stay with you for life, even if you enroll later.

The only way to avoid these penalties after missing your Initial Enrollment Period is to have had creditable coverage — health insurance through your employer, your spouse's employer, TRICARE, the Veterans Administration, or certain other sources. If you had creditable coverage when you turned 65, you can enroll later without penalty, but you must enroll within eight months of losing that coverage.

If you believe you have a may have access to reason for missing your important date — such as incorrect information from Medicare, a serious illness, or language barriers — you can request a Special Enrollment Period. Contact Medicare at 1-800-MEDICARE to explain your situation.

Employer Coverage and Delayed Enrollment

If you are still working at 65 and covered by your employer's health plan, you do not have to enroll in Medicare when ready. You can delay Part B enrollment without penalty as long as your employer has 20 or more employees. Your employer's coverage is considered primary, meaning it pays first, and Medicare pays second.

When you leave your job or lose your employer coverage, you have eight months to enroll in Medicare Part B without penalty. This eight-month window is separate from your Initial Enrollment Period. For example, if you turn 65 while still employed and do not enroll, then leave your job at 68, you have until eight months after leaving to enroll without penalty.

Part A (hospital insurance) works differently. If your employer has 20 or more employees, you can delay Part A enrollment without penalty. However, if your employer has fewer than 20 employees, you must enroll in Part A when you turn 65, even if you are still working.

General Enrollment Period and Other Enrollment Windows

If you miss your Initial Enrollment Period and do not have creditable coverage, you can still enroll during the General Enrollment Period, which runs January 1 through March 31 each year. Coverage begins July 1 of that year. However, late penalties still explore unless you have a may have access to reason for the delay.

Special Enrollment Periods are available if you experience certain life events: losing employer coverage, moving out of your plan's service area, becoming may be able to access for Medicaid, or having a family member enroll in Medicare. If you may have access to for a Special Enrollment Period, you can enroll outside the normal windows without penalty.

How to Enroll in Medicare

You can enroll through three main channels. Online at Medicare.gov is the fastest option — you can complete the process in about 10 minutes. By phone, call 1-800-MEDICARE (1-800-633-4227). Representatives are available seven days a week, 24 hours a day. In person at your local Social Security office, though you will need to make an appointment.

When you enroll, have your Social Security number, birth date, and citizenship or immigration status ready. If you are enrolling in Part D (prescription drug coverage), bring a list of your current medications so you can compare plans. You will choose between Original Medicare (Part A and B) or a Medicare Advantage plan, and you will select a prescription drug plan if you want Part D coverage.

After you enroll, Medicare will mail your card within two weeks. Your coverage typically begins on the first day of the month you turn 65, or the first day of the month after you enroll, depending on when you submit your enrollment.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65?

Yes, if you receive SSDI for 24 months, or if you have end-stage renal disease or ALS, you can enroll at any time. Otherwise, you must wait until three months before your 65th birthday. If you are still working and covered by your employer, you can delay enrollment without penalty until you leave that job.

What if I turn 65 and I am still working?

You do not have to enroll in Medicare when ready if your employer has 20 or more employees and you are covered by their health plan. You can delay Part B enrollment without penalty. When you leave your job, you have eight months to enroll without penalty. Part A rules are different — if your employer has fewer than 20 employees, you must enroll in Part A at 65.

How much will I pay in penalties if I miss my enrollment important date?

Part B premiums increase by 10 percent for each full year you were may be able to access but not enrolled. Part D premiums increase by 1 percent for each month you were may be able to access but not enrolled. These penalties are permanent and explore every month you have Medicare. For example, if you delay Part B by three years, your premium increases by 30 percent for life.

What if I already have health insurance through my job when I turn 65?

If your employer has 20 or more employees, your employer coverage is primary and you can delay Medicare enrollment. You have eight months after leaving that job to enroll in Part B without penalty. If your employer has fewer than 20 employees, you must enroll in Part A at 65, but you can still delay Part B if you are covered by the employer plan.

Can I change my mind after I enroll?

Yes. You have a seven-month Initial Enrollment Period, so if you enroll early and change your mind, you can switch plans during that window. After your Initial Enrollment Period ends, you can make changes during the Annual Enrollment Period (October 15 to December 7 each year) or if you experience a may have access to life event.