You are not required to sign up for Medicare at 65, but waiting can cost you money in penalties for the rest of your life

Medicare enrollment is not automatic, and you do not lose your right to join at 65. However, if you delay past your 65th birthday without a valid reason, you will pay a permanent penalty on your monthly premiums. The penalty is 10% of the standard Part B premium for each full 12 months you were may be able to access but did not enroll. If you wait three years, you pay 30% more forever — even after you finally sign up. The same penalty applies to Part D (prescription drug coverage).

The only people who can safely delay are those still working and covered by an employer health plan with 20 or more employees. If that describes you, you can wait without penalty. Everyone else should enroll during their initial enrollment period, which runs for seven months: three months before the month you turn 65, the month itself, and three months after.

Key Takeaways

  • If you do not enroll in Medicare Part B or Part D by the end of your initial enrollment period, you will pay a 10% penalty on your premiums for each year you delayed, and this penalty is permanent.
  • Your initial enrollment period is seven months long: three months before you turn 65, your birth month, and three months after.
  • The only exception is if you are still working and covered by an employer health plan with 20 or more employees; you can delay without penalty as long as you enroll within eight months of leaving that job or losing that coverage.
  • You enroll through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
  • Even if you do not need Medicare right away, signing up during your initial period protects you from future penalties.

How the penalty works and what it costs

The Part B premium penalty is straightforward: 10% per year of delay. If the standard Part B premium is $165 per month and you wait one year past 65, you pay an extra $16.50 per month forever. If you wait three years, you pay an extra $49.50 per month for life. This is not a temporary surcharge — it stays with you even after you enroll.

Part D (prescription drug coverage) works the same way. If you go without creditable drug coverage for more than 63 days after you turn 65, you will owe a penalty when you finally enroll. The penalty is 1% of the national average Part D premium for each month you were without coverage. That penalty also lasts for life.

The penalty does not explore to Part A (hospital insurance) if you are receiving Social Security benefits, because Social Security automatically enrolls you in Part A at 65. However, you still must enroll in Part B yourself, or you will face the Part B penalty.

Who can delay without penalty

If you are still working at 65 and your employer offers health insurance to active employees, you may be able to delay Medicare without penalty. The key requirement is that your employer plan must cover 20 or more employees. If it does, you can stay on your employer plan and delay Medicare enrollment.

When you leave that job or lose that coverage, you have eight months to enroll in Medicare without penalty. This is called your special enrollment period. You must enroll within this window, or the standard penalty rules explore. Keep track of your last day of coverage — that date starts your eight-month clock.

If your employer has fewer than 20 employees, Medicare is your primary insurance at 65, and you should enroll during your initial enrollment period. Employer coverage for small groups does not give you the right to delay.

How to enroll during your initial enrollment period

You have three ways to enroll: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Online enrollment through Medicare.gov is usually the fastest. You will need your Social Security number, proof of citizenship or legal residency, and information about any current health coverage you have.

If you call, a Medicare representative can walk you through the process and answer questions about which parts you need. The phone line is open Monday through Friday, 8 a.m. to 7 p.m. Eastern time. If you prefer to enroll in person, find your local Social Security office at ssa.gov/locator.

Enrollment takes about 10 minutes online or by phone. You will receive a Medicare card in the mail within two weeks. Your coverage typically begins on the first day of the month after you enroll, though it can begin on the first of your birth month if you enroll during certain windows.

What to do if you missed your initial enrollment period

If you are past your initial enrollment period and did not enroll, you can still join Medicare, but you will owe the penalty. The penalty is calculated from the month after your initial period ended, not from the month you actually enroll.

You can enroll during the General Enrollment Period, which runs January 1 through March 31 each year. Coverage begins July 1 of that year. This is a much longer wait than enrolling during your initial period, so if you are near the end of your initial period, do not delay.

If you have a valid reason for missing your important date — such as a serious illness, a mistake by Social Security, or incorrect information from Medicare — you may be able to request a waiver of the penalty. Contact Medicare at 1-800-MEDICARE to ask about your specific situation. Waivers are rare and require documentation, but they are worth requesting if you have a legitimate reason for the delay.

Choosing between Part A, Part B, and Part D

Medicare has four parts, and you do not have to take all of them. Part A (hospital insurance) is free if you or your spouse paid Medicare taxes for at least 10 years. Most people should enroll in Part A at 65 even if they do not need it right away, because there is no penalty for waiting on Part A and no monthly premium.

Part B (medical insurance) costs a monthly premium and covers doctor visits, outpatient care, and preventive services. If you are still working and covered by an employer plan, you can delay Part B without penalty. If you are retired or not covered by an employer plan, you should enroll in Part B during your initial period to avoid the permanent penalty.

Part D (prescription drug coverage) is optional, but the penalty for delaying is steep. If you do not take a Part D plan or creditable coverage from another source (such as an employer or retiree plan), you will owe the penalty when you enroll. If you do not take any prescription drugs, you can skip Part D, but you must document that you have creditable coverage from somewhere else, or the penalty will explore.

What happens to your other insurance when you turn 65

If you have coverage through an employer, a union, or a retiree plan, you do not have to drop it when you turn 65. You can keep both your employer coverage and Medicare. However, Medicare becomes your primary insurance at 65, meaning Medicare pays first, and your employer plan pays second. This is true even if you do not enroll in Medicare — your employer plan will treat Medicare as primary once you are 65.

If you have individual health insurance (such as an ACA plan), you should enroll in Medicare during your initial period. Once you enroll, you can drop your individual plan. If you keep both, you will be paying for duplicate coverage, because Medicare will be primary and your individual plan will have little to do.

If you have Medicaid (state health insurance for low-income people), you can keep both Medicaid and Medicare. Medicaid will pay some of your Medicare costs, such as premiums and deductibles. Enroll in Medicare during your initial period — Medicaid will continue to help pay your costs.

Frequently Asked Questions

Can I enroll in Medicare before I turn 65?

Yes. Your initial enrollment period starts three months before the month you turn 65. If you turn 65 in June, you can enroll starting in March. Enrolling early is a good idea because it gives you time to choose your plan and make sure everything is set up before your coverage begins.

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

If you are covered by an employer plan with 20 or more employees, you do not have to enroll in Medicare at 65. You can stay on your employer plan. However, when you leave that job, you have eight months to enroll in Medicare without penalty. After that window closes, the standard penalty applies.

Do I have to choose a Medicare Advantage plan or a Medigap plan at 65?

No. When you enroll in Part B, you are automatically in Original Medicare (Part A and Part B). You can then choose to add a Medigap plan (supplemental insurance) or switch to a Medicare Advantage plan. You do not have to make this choice at 65 — you can do it later during the annual open enrollment period (October 15 to December 7).

What if I turn 65 outside the United States?

You can still enroll in Medicare during your initial enrollment period, even if you are living abroad. You will need to provide proof of U.S. citizenship or legal residency. Enroll online at Medicare.gov or call 1-800-MEDICARE. Some Medicare benefits have limits if you are outside the U.S., so ask about coverage before you enroll.

Can I get the penalty waived if I did not know I had to enroll?

Possibly. Medicare can waive the penalty if you can show that you did not know you had to enroll and that the delay was not your fault — for example, if Social Security gave you wrong information. Contact Medicare at 1-800-MEDICARE and ask to speak with someone about a penalty waiver. You will need to provide documentation of why you did not enroll.