When You Can Enroll in Medicare

You become may be able to access for Medicare at age 65, regardless of your work history or income. Enrollment does not happen automatically — you must take action during specific windows, or you will face late penalties that last for life. The enrollment periods are fixed by federal law and do not change based on your situation.

Your Initial Enrollment Period runs for seven months: three months before the month you turn 65, the month you turn 65, and three months after. If you turn 65 in June, your window opens in March and closes in September. Most people should enroll during this window. If you miss it, you enter a General Enrollment Period that runs January 1 through March 31 each year, but you will pay a permanent penalty on your premiums.

If you are still working and covered by your employer's health plan at 65, you may be able to delay enrollment without penalty. You must have creditable coverage — meaning your employer plan covers at least as much as Medicare Part B would. When you finally leave that job or lose the coverage, you get an eight-month Special Enrollment Period to sign up without penalty. You will need to prove you had creditable coverage; your employer's benefits office can provide a letter stating this.

Key Takeaways

  • You become may be able to access for Medicare at 65, and your enrollment window is seven months long: three months before, the month of, and three months after your 65th birthday.
  • Enrollment does not happen automatically — you must sign up yourself through Medicare.gov, by phone, or in person at a Social Security office.
  • If you miss your Initial Enrollment Period and do not have creditable employer coverage, you will pay a permanent 10 percent penalty on Part B premiums for as long as you have Medicare.
  • If you are still working at 65 with employer health coverage, you can delay Medicare enrollment and sign up later without penalty, as long as you enroll within eight months of losing that coverage.
  • Medicare has four parts — A (hospital), B (doctor visits), D (prescription drugs), and C (private alternative) — and you choose which ones you need based on your situation.

How to Enroll: The Three Routes

You can enroll through Medicare.gov, by phone, or in person. The online route is fastest. Go to Medicare.gov, click "Sign up for Medicare," and log in with your Social Security number or create a Medicare.gov account. The process takes 10 to 15 minutes and you will receive confirmation when ready. You can enroll any day of the week, any time.

If you prefer to speak with someone, call Social Security at 1-800-772-1213. They handle Medicare enrollment and can walk you through your choices. Wait times are shortest early in the morning and on weekdays. You can also visit your local Social Security office in person — find the nearest one at ssa.gov/locator. Bring your Social Security card, proof of citizenship (passport or birth certificate), and proof of residence (utility bill or lease).

Whichever route you choose, have this information ready: your date of birth, citizenship status, and details about any current health coverage. If you are still working, have your employer's plan documents or a benefits summary available so you can confirm whether your coverage is creditable.

Understanding Medicare Parts and What You Need to Choose

Part A covers hospital stays, skilled nursing care, and hospice. It is free for nearly everyone at 65 because you or your spouse paid Medicare taxes while working. You do not choose whether to take Part A — it is automatic if you are a U.S. citizen or permanent resident who has lived in the country for at least five years. You should enroll in it even if you plan to delay Part B.

Part B covers doctor visits, outpatient care, lab work, and medical equipment. It costs a monthly premium (the standard amount in 2024 is $164.90, but it varies by income). You must actively choose Part B during your enrollment window. If you have creditable employer coverage, you can delay it. If you do not, and you miss your window, you pay a permanent 10 percent penalty on top of your premium for each year you were may be able to access but not enrolled.

Part D is prescription drug coverage. It is optional but important if you take medications regularly. Plans vary widely in which drugs they cover and what you pay. You can enroll in Part D during your Initial Enrollment Period, or during the Annual Enrollment Period (October 15 through December 7 each year). If you go without Part D when you are first may be able to access and do not have other creditable drug coverage, you pay a permanent penalty when you finally enroll.

Part C, also called Medicare Advantage, is a private alternative to Parts A and B. It bundles hospital and doctor coverage into one plan, usually with a lower premium than Part B alone, but with network restrictions and higher out-of-pocket costs. You can enroll in Part C during your Initial Enrollment Period or during the Annual Enrollment Period. If you choose Part C, you are still covered by Part A and can add Part D separately.

What Happens After You Enroll

Once you enroll, Medicare sends you a Medicare card in the mail within two weeks. Your coverage begins on the first day of the month you turn 65, or the first day of the month after you enroll, whichever is later. If you enroll in March when you turn 65, coverage starts April 1. If you enroll in September after missing your window, coverage starts October 1.

Before your coverage begins, review your enrollment confirmation to make sure all your information is correct — name, date of birth, Social Security number. If anything is wrong, contact Medicare at 1-800-MEDICARE (1-800-633-4227) to fix it. Errors on your card can cause claims to be denied.

Once coverage starts, you can use your Medicare card at any hospital, doctor's office, or pharmacy that accepts Medicare. Not all providers do — ask before your first visit. You are responsible for any costs Medicare does not cover, such as deductibles and coinsurance, unless you have supplemental coverage (Medigap) or are enrolled in a Medicare Advantage plan.

Late Penalties and How They Work

If you miss your Initial Enrollment Period and do not have creditable coverage, you pay a permanent penalty on Part B premiums. 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 three years and did not enroll, you pay 30 percent extra on your premium for life — even after you finally sign up.

The same rule applies to Part D. If you go without prescription drug coverage when you are first may be able to access and do not have other creditable drug coverage, you pay a 1 percent penalty for each month you were may be able to access but not enrolled. That penalty is added to your Part D premium permanently.

These penalties do not expire. They follow you as long as you have Medicare. The only way to avoid them is to enroll during your Initial Enrollment Period, or to prove you had creditable coverage from another source during the time you were not enrolled in Medicare.

Special Situations: Still Working, Losing Coverage, or Moving

If you are still working at 65 and your employer has 20 or more employees, your employer's health plan is primary — it pays first, and Medicare is secondary. You can delay Part B enrollment without penalty as long as you are actively working and covered by that plan. When you leave the job or lose coverage, you have eight months to enroll in Part B without penalty. You must enroll within this window or face permanent penalties.

If you are covered by a spouse's employer plan, the same rule applies — you can delay Part B as long as the coverage is active. When it ends, you have eight months. Get a letter from your spouse's employer stating the coverage dates and that it was creditable; Medicare will ask for this when you enroll late.

If you are moving to a different state, your Medicare coverage does not change — Medicare is federal and works the same everywhere. However, if you are in a Medicare Advantage plan, you may need to switch plans because many plans do not cover out-of-state. Contact your plan before you move to see whether your coverage continues or whether you need to enroll in a new plan.

Frequently Asked Questions

What if I turn 65 but am not a U.S. citizen?

You can enroll in Medicare if you are a permanent resident (green card holder) and have lived in the United States for at least five years. If you are not a permanent resident, you are not may be able to access for Medicare based on age. You may be may be able to access through a different route if you have been paying Medicare taxes for a certain number of years, but this is rare. Contact Social Security to discuss your specific situation.

Can I enroll in Medicare before I turn 65?

Your enrollment window opens three months before the month you turn 65, so yes — you can enroll up to three months early. Many people do this to make sure their coverage starts on time. You cannot enroll more than three months early.

Do I have to enroll in Part B if I have private insurance?

If your private insurance is creditable coverage from an employer (yours or your spouse's), you can delay Part B without penalty. If it is private insurance you bought yourself on the individual market, it does not count as creditable coverage, and you should enroll in Part B during your Initial Enrollment Period to avoid penalties.

What if I miss my enrollment window?

You can enroll during the General Enrollment Period, which runs January 1 through March 31 each year. Coverage begins July 1 of that year. However, you will pay a permanent 10 percent penalty on your Part B premium. If you have a valid reason for missing your window (such as losing creditable coverage), you may be able to request a Special Enrollment Period; contact Medicare to ask.

How do I know which Medicare plan is right for me?

This depends on your health, medications, and doctors. Medicare.gov has a plan comparison tool where you enter your prescriptions and preferred doctors, and it shows you which plans cover them and what you would pay. You can also call 1-800-MEDICARE to speak with someone who can walk you through your options based on your situation.