You do not automatically have to explore for Medicare at 65, but waiting can cost you money in penalties for the rest of your life

Medicare enrollment is not automatic. You must take action 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 miss this window and do not have coverage through an employer or union, you will pay a permanent penalty on your premiums.

The penalty exists because Medicare is designed to spread risk across people who enroll when they are supposed to. If you wait until you are 70 to sign up, you have already gone five years without paying into the system while healthy. Medicare charges you for that choice by raising your Part B and Part D premiums by 10 percent for each year you delayed — and that increase stays with you permanently, even after you finally enroll.

There is one major exception: if you are still working and covered by your employer's health plan, you can delay enrollment without penalty, as long as your employer has 20 or more employees. You will have a special enrollment period of eight months after you leave that job to sign up without penalty.

Key Takeaways

  • Your Initial Enrollment Period is seven months long — three months before your 65th birthday, your birth month, and three months after — and you must enroll during this time to avoid permanent penalties.
  • If you miss your Initial Enrollment Period and do not have employer coverage, you will pay a 10 percent penalty on Part B and Part D premiums for each year you delayed, for the rest of your life.
  • If you are still working and covered by an employer plan with 20 or more employees, you can delay Medicare without penalty and have eight months after you leave that job to enroll.
  • You enroll through Social Security, Medicare.gov, or by calling 1-800-MEDICARE, and the process takes about 15 minutes online or on the phone.

Who has to enroll and who can wait

You must enroll during your Initial Enrollment Period if you are not covered by an active employer or union health plan. This includes people who are retired, self-employed, or unemployed. If you have coverage through your current job or your spouse's current job, you can delay without penalty as long as that employer has at least 20 employees.

The employer coverage exception is strict about one thing: it must be active coverage right now, not coverage you had in the past. If you retired last year and kept COBRA for a few months, that does not count. If you are on your spouse's plan and they are still working, that counts. If you are on your spouse's retiree plan, that does not count — retiree plans are not considered active employer coverage for this purpose.

If you are unsure whether your coverage qualifies, call 1-800-MEDICARE and ask. The penalty is permanent, so it is worth the phone call to confirm.

What happens if you miss your Initial Enrollment Period

If you do not enroll during your seven-month window and you do not have may have access to employer coverage, you enter a waiting period. You can still enroll, but only during the General Enrollment Period, which runs January 1 through March 31 each year. Your coverage would then start July 1 of that year.

During the months you are not enrolled, you have no Medicare coverage. If you need medical care, you pay out of pocket. You also begin accumulating the late enrollment penalty on Part B and Part D. The penalty is 10 percent of the standard premium for each full year you were may be able to access but not enrolled. That percentage is added to your premium permanently — it does not go away after a few years.

Example: The standard Part B premium in 2024 is $164.90 per month. If you were may be able to access for two years but did not enroll, your penalty would be 20 percent of $164.90, or about $33 per month, added to your premium for life. If you wait five years, the penalty is 50 percent, or about $82 per month, for life.

How to enroll during your Initial Enrollment Period

You have three ways to enroll: online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office. Online enrollment through Medicare.gov takes about 15 minutes. You will need your Social Security number and information about any current health coverage.

When you enroll, you choose which parts of Medicare you want. Most people enroll in Part A (hospital insurance) and Part B (medical insurance). You can also choose a Medigap plan or a Medicare Advantage plan to cover costs that Part A and B do not pay. If you take prescription drugs, you should also enroll in Part D (prescription drug coverage) during this period, or you will face a separate late enrollment penalty on that part.

Enroll as early as possible in your seven-month window. Social Security processes applications in the order they receive them, and coverage can take time to set up. If you enroll in the last month of your period, you risk missing the January 1 start date and having a gap in coverage.

The special enrollment period for people still working

If you are still working and covered by your employer's health plan, you do not have to enroll at 65. You can continue on your employer plan as long as you work there and the plan continues. When you leave that job — whether you retire, change jobs, or are laid off — you have eight months to enroll in Medicare without penalty.

This eight-month window is called your Special Enrollment Period. It starts the month after your employer coverage ends. You must enroll during this time to avoid the late enrollment penalty. If you do enroll during this period, your Part B coverage can start as early as the first day of the month after you lose your employer coverage.

Tell your employer's benefits department that you are leaving and ask them to confirm the exact date your coverage ends. Use that date to calculate your eight-month window. Mark your calendar for the last day of that window so you do not miss it.

What to do if you already missed your enrollment period

If you are past your Initial Enrollment Period and you do not have employer coverage, you can still enroll, but you will owe a late enrollment penalty. You can enroll during the General Enrollment Period (January 1 through March 31 each year), and your coverage will start July 1 of that year.

If you have a may have access to life event — such as losing employer coverage, moving to a new state, or becoming a U.S. citizen — you may have a Special Enrollment Period that lets you enroll outside the General Enrollment Period without penalty. Call 1-800-MEDICARE to ask whether your situation qualifies.

Even if you owe a penalty, enroll as soon as you can. The penalty grows with each year you delay, and you have no coverage in the meantime. The sooner you enroll, the sooner the penalty stops growing.

Frequently Asked Questions

Can I turn down Medicare and keep my private insurance instead?

You can decline Medicare Part A and Part B if you have active employer coverage, but you cannot decline Part A permanently without penalty if you are not working. If you turn down Part B during your Initial Enrollment Period without may have access to employer coverage, you will owe a 10 percent penalty on Part B for life when you eventually enroll.

What if I am still working past 65 and do not want Medicare yet?

If your employer plan covers you, you do not have to enroll. You can stay on your employer plan and enroll in Medicare later when you leave that job. You will have eight months after your coverage ends to enroll without penalty. Do not wait longer than eight months.

Does Social Security automatically sign me up for Medicare?

No. Social Security will send you information about Medicare enrollment about three months before your 65th birthday, but you must complete the enrollment yourself. If you do not act, you will not be enrolled, even if you are receiving Social Security benefits.

What if I am not a U.S. citizen but I live here?

You must be a U.S. citizen or permanent resident to enroll in Medicare. If you are a permanent resident, you must have lived in the United States for at least five years. Call 1-800-MEDICARE to discuss your specific situation.

Can I change my mind after I enroll?

Yes, but only during certain times. You have until the end of your Initial Enrollment Period to change your choices. After that, you can make changes during the Annual Enrollment Period (October 15 through December 7 each year), and changes take effect January 1 of the following year.