Sign up for Medicare during your Initial Enrollment Period, which starts three months before the month you turn 65 and lasts for seven months total

Your Initial Enrollment Period is a seven-month window centered on your 65th birthday month. It begins three months before that month, includes the month itself, and continues for three months after. For example, if you turn 65 in June, your period runs from March through September. You can sign up any time during those seven months, and coverage can start as early as the first day of the month you turn 65.

If you miss this window, you can still sign up later, but you may face late enrollment penalties — permanent increases to your monthly premiums that stay with you for life. The penalty amount depends on how long you went without coverage. This is why signing up during your Initial Enrollment Period matters: it protects you from paying more for the same coverage.

You do not have to wait until you turn 65 to start thinking about Medicare. Many people begin reading about their options months ahead, and that preparation time is well spent. The choices you make during enrollment shape your coverage and costs for the year ahead.

Key Takeaways

  • Your Initial Enrollment Period lasts seven months: three months before your 65th birthday month, the month itself, and three months after.
  • You can sign up online at Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office during your enrollment window.
  • If you miss your Initial Enrollment Period, you can sign up during the General Enrollment Period (January 1 through March 31 each year), but late penalties will explore.
  • Some people may have access to for Special Enrollment Periods outside the normal windows if they lose employer coverage or move to a new state.
  • Signing up early in your enrollment period gives you time to resolve any problems before coverage starts.

How to sign up during your Initial Enrollment Period

You have three ways to sign up: online, by phone, or in person. The online route is fastest. Go to Medicare.gov, click "Sign up for Medicare," and follow the steps. You will need your Social Security number, date of birth, and information about any current health or prescription drug coverage. The system will show you what parts of Medicare you are may be able to access for and let you choose your plan on the spot.

If you prefer to speak with someone, call 1-800-MEDICARE (1-800-633-4227). Representatives are available seven days a week, and they can walk you through your options and submit your enrollment right over the phone. This is a good choice if you have questions about which plan fits your situation or if you need help understanding the differences between plans.

You can also visit your local Social Security office in person. Bring your Social Security card, proof of citizenship or legal residency, and proof of age. Staff there can help you sign up for Medicare Part A and Part B. If you want to add prescription drug coverage (Part D) or a Medicare Advantage plan, you may need to complete that part online or by phone, since Social Security offices handle Part A and B enrollment.

What happens if you miss your Initial Enrollment Period

If you do not sign up during your seven-month window, you enter a different enrollment timeline. The next chance to sign up is the General Enrollment Period, which runs from January 1 through March 31 each year. Coverage under a plan you sign up for during this period starts July 1 of that year. This means if you miss your Initial Enrollment Period in September and do not sign up until February, you will have a gap in coverage from October through June.

More importantly, you will owe a late enrollment penalty on your Part B premium. The penalty is 10 percent of the standard Part B premium for each full year you were may be able to access but not enrolled. If you were may be able to access for two years and did not sign up, your penalty is 20 percent of the standard premium — and you pay it for as long as you have Medicare. The same rule applies to Part D (prescription drug coverage): missing the important date costs you 1 percent of the national average Part D premium for each month you were without coverage.

There are narrow exceptions. If you had creditable coverage through an employer or union while you were working, you may not owe a penalty, even if you sign up late. Creditable coverage means the plan was at least as good as Medicare Part D. You will need to show proof of this coverage when you sign up. If you are unsure whether your old plan counted as creditable, contact your former employer's benefits office or the plan administrator.

Special Enrollment Periods for life changes

Certain events open enrollment windows outside the normal periods. These Special Enrollment Periods let you sign up or change plans without waiting for the General Enrollment Period. Common may have access to events include losing employer coverage when you retire, moving to a different state, or having a major change in your income.

If you lose health coverage through an employer or union, you usually have two months from the date coverage ends to sign up for Medicare without a late penalty. If you move to a new state, you have two months to change your Medicare Advantage or Part D plan to one available in your new location. If your income drops significantly, you may become newly may be able to access for programs like Medicaid or the Low-Income Subsidy for prescription drugs, which also opens a Special Enrollment Period.

To use a Special Enrollment Period, you will need to prove the may have access to event. Gather documents like a letter from your employer saying coverage ended, a lease or deed showing your new address, or tax documents showing a change in income. When you call 1-800-MEDICARE or sign up online, tell the representative about the event and provide these documents. They will confirm whether you may have access to for the Special Enrollment Period and help you complete your enrollment.

Signing up for different parts of Medicare at different times

Medicare has four parts, and the enrollment rules differ slightly for each. Part A (hospital insurance) and Part B (medical insurance) are enrolled together during your Initial Enrollment Period. Most people do not pay a premium for Part A if they or their spouse paid Medicare taxes while working, so there is no financial penalty for signing up late for Part A alone. However, Part B has the late penalty described above.

Part D (prescription drug coverage) has its own enrollment important date: the end of your Initial Enrollment Period for Medicare. If you do not sign up for Part D when you first become may be able to access and you go without creditable drug coverage, you will owe a penalty of 1 percent of the national average Part D premium for each month you were without it. This penalty also lasts for life.

Medicare Advantage (Part C) is an alternative to Original Medicare (Parts A and B). You can sign up for it during your Initial Enrollment Period or during the Annual Enrollment Period (October 15 through December 7 each year). If you have Original Medicare and want to switch to Medicare Advantage, you can do so during the Annual Enrollment Period without penalty.

The Annual Enrollment Period for changes after your first year

Once you are enrolled in Medicare, you get another chance to change your coverage each year during the Annual Enrollment Period, which runs from October 15 through December 7. During this window, you can switch from Original Medicare to Medicare Advantage, switch between Medicare Advantage plans, add or drop Part D coverage, or switch to a different Part D plan. Changes made during this period take effect January 1 of the following year.

You do not have to make changes every year. If your current plan still works for you, you can keep it. But if your doctors are no longer in your plan's network, your medications are no longer covered, or you want to try a different plan, the Annual Enrollment Period is when you can do it without penalty.

Mark October 15 on your calendar each year as a reminder to review your coverage. Medicare sends you a notice in the mail before the enrollment period starts, and you can also check your coverage options on Medicare.gov anytime.

Frequently Asked Questions

What if I am still working at 65 — do I still need to sign up for Medicare?

If you or your spouse are still working and have employer coverage, you may be able to delay signing up for Part B without a late penalty. This is called the Special Enrollment Period for active workers. You must have group health insurance through your current employer, and you can sign up for Part B within eight months after your employment ends or your coverage stops, whichever comes first. Part A (hospital insurance) has different rules; you should still sign up for it even if you are working, since there is usually no premium.

Can I sign up for Medicare before I turn 65?

Your enrollment period begins three months before the month you turn 65, so yes — you can sign up up to three months early. Many people do this to make sure coverage starts on their 65th birthday or the first day of the month they turn 65. Signing up early also gives you time to ask questions or fix any errors before coverage begins.

What if I turn 65 on the first day of the month?

Your Initial Enrollment Period still runs three months before that month through three months after. If you turn 65 on January 1, your enrollment period runs from October of the previous year through April. You can sign up anytime during this window, and coverage can start as early as January 1.

Do I have to sign up in person, or can I do it all online?

You can sign up entirely online at Medicare.gov or by phone at 1-800-MEDICARE. You do not have to visit a Social Security office unless you prefer to do so. Online and phone enrollment are faster and available outside of office hours.

What documents do I need to sign up?

You will need your Social Security number and date of birth. If you are signing up online, you can complete enrollment with just these two pieces of information. If you are signing up in person at a Social Security office, bring your Social Security card, proof of citizenship or legal residency (passport, birth certificate, or naturalization papers), and proof of age.