Medicare starts automatically after you've been on SSDI for 24 months

You do not need to sign up for Medicare yourself. Social Security enrolls you automatically in both Medicare Part A (hospital insurance) and Medicare Part B (medical insurance) once you have been receiving SSDI payments for 24 consecutive months. The enrollment happens in the third month of your 25th month on SSDI, and your coverage begins on the first day of that month.

This automatic enrollment is one of the few things in the SSDI process that happens without you having to file forms or make phone calls. However, you do need to know when it's happening and what to do when your Medicare card arrives, because Part B has a monthly premium that will be deducted from your SSDI check unless you take action to decline it.

If you are already receiving Social Security retirement or survivor benefits when you become disabled, your 24-month waiting period may have already started or even ended. Social Security counts any months you spent on those other benefit types toward the 24 months, so your Medicare enrollment date might come sooner than you expect.

Key Takeaways

  • Medicare Part A and Part B enroll you automatically after 24 months on SSDI; you will receive your Medicare card in the mail without filing anything.
  • Your Medicare coverage begins on the first day of the month in which you complete 24 months, and Social Security will deduct the Part B premium from your SSDI payment unless you decline Part B in writing.
  • You can decline Part B when you receive your Medicare card, but declining it may result in a permanent penalty if you enroll later, so the decision should be made carefully.
  • If you have other health insurance through an employer or a family member's job, you may want to contact Medicare before your enrollment date to discuss whether to accept or decline Part B.
  • Social Security will send you a notice about your Medicare enrollment roughly three months before your coverage begins, giving you time to prepare.

When your Medicare card will arrive

Social Security sends you a notice called the "Medicare Entitlement Notification" about three months before your coverage begins. This notice tells you your Medicare number, your coverage start date, and what you need to do next. The notice arrives by mail at the address Social Security has on file for you.

Your actual Medicare card arrives separately, usually within two weeks of your coverage start date. If you do not receive your card within a month of your coverage beginning, you can call Medicare at 1-800-MEDICARE (1-800-633-4227) to request a replacement. You do not need the physical card to use Medicare—your coverage is active on the date listed in the notification—but you will need the number on the card for doctor visits and hospital stays.

If your address has changed since you started receiving SSDI, update it with Social Security before your 24-month mark approaches. You can change your address online at ssa.gov, by phone at 1-800-772-1213, or in person at your local Social Security office. Updating your address ensures both the notification and the card reach you.

What happens to your SSDI payment when Medicare starts

When Medicare Part B enrollment happens, Social Security automatically deducts the monthly Part B premium from your SSDI check. For 2024, this premium is $164.90 per month for most people, though the amount changes each year. The deduction begins the same month your coverage starts.

If you do not want Part B coverage, you can decline it. To decline, you must contact Social Security in writing or by phone after you receive the Medicare Entitlement Notification but before your coverage begins. You can call 1-800-772-1213 or visit your local Social Security office. If you decline Part B, no premium will be deducted from your SSDI payment.

Part A (hospital insurance) has no monthly premium for most people, so you cannot decline it. Part A covers hospital stays, skilled nursing facility care, hospice, and some home health services. Part B covers doctor visits, outpatient care, medical equipment, and preventive services. Many people keep both because the combination covers most medical expenses.

If you have other health insurance when Medicare starts

If you are covered by an employer's health plan or by a family member's insurance through their job, you may want to keep that coverage instead of accepting Medicare Part B. This situation is common for people who became disabled while still working or whose spouse still works.

Before your Medicare enrollment date, contact the employer plan's benefits administrator and ask whether you should enroll in Medicare Part B. Some employer plans coordinate with Medicare and work better if you have both. Others work better if you stay on the employer plan alone. The answer depends on the specific plan and your situation.

If you decline Part B now because you have employer coverage, you can enroll in Part B later without a permanent penalty—but only during specific enrollment periods. If you wait until after your employer coverage ends, you have eight months to enroll in Part B without penalty. After that window closes, you may face a late enrollment penalty for as long as you have Medicare.

Declining Part B and the penalty for late enrollment

If you decline Part B when you first become may have access to to Medicare, you can change your mind later. However, the rules about penalties are strict. If you enroll in Part B more than 12 months after your initial enrollment period ends, you will pay a permanent penalty on top of the regular premium for as long as you have Medicare.

The penalty is 10 percent of the Part B premium for each 12-month period you were may have access to to Part B but did not enroll. For example, if you decline Part B at age 65 and enroll at age 68, you would have been may have access to for three years. Your penalty would be 30 percent of the current Part B premium, added to your premium forever.

The exception to this penalty is if you had creditable coverage—meaning health insurance through an employer or a family member's job—for the entire time you were not enrolled in Part B. If you had continuous employer coverage and then enroll in Part B within eight months of that coverage ending, you will not face a penalty. Keep records of your employer coverage dates in case you need to prove this later.

What to do when your Medicare card arrives

When you receive your Medicare card, check the information on it for accuracy. Your name, date of birth, and Medicare number should all be correct. If anything is wrong, call Medicare at 1-800-MEDICARE to request a corrected card.

Keep your Medicare card in a safe place, but you do not need to carry it everywhere. When you go to a doctor or hospital, give them your Medicare number. You can provide it verbally or show them the card. If you lose your card, you can request a replacement by calling 1-800-MEDICARE or by logging into your Medicare account at Medicare.gov.

After your Medicare coverage begins, you will receive a document called the "Medicare Summary Notice" every three months. This notice shows what Medicare paid on your behalf. Review it to make sure the charges are for services you actually received. If you see charges you do not recognize, contact Medicare when ready.

Understanding your coverage gaps and costs

Medicare Part A and Part B do not cover everything. Part A has a deductible for hospital stays, and Part B requires you to pay 20 percent of the cost of most doctor visits and outpatient services after you meet the Part B deductible. Prescription drugs are not covered by Part A or Part B.

Many people on SSDI choose to enroll in Medicare Part D (prescription drug coverage) or a Medicare Advantage plan (Part C), which combines Parts A and B and often includes Part D. These are optional, and you enroll in them separately during specific enrollment periods. Part D has a monthly premium, and Medicare Advantage plans may have premiums as well.

You may also be may have access to to Medicaid, which is a separate program run by your state that covers costs Medicare does not. Medicaid rules vary by state, but many states cover the Part B premium and the 20 percent cost-sharing that Medicare requires. Contact your state Medicaid office or call 211 to find out whether you may have access to.

Frequently Asked Questions

What if I turn 65 while I'm on SSDI?

Your SSDI automatically converts to Social Security retirement benefits at age 65, and the payment amount stays the same. Your Medicare coverage does not change. You keep the same Medicare card and the same coverage. From Social Security's perspective, you are now a retiree rather than a disabled worker, but your benefits and Medicare work the same way.

Can I decline Medicare Part A?

No. Part A enrollment is mandatory and happens automatically. You cannot decline it, and there is no premium deducted from your SSDI check for Part A. You can only decline Part B, which is optional.

What if I'm working and earning money while on SSDI?

Your work does not affect your Medicare enrollment. After 24 months on SSDI, you enroll in Medicare regardless of how much you earn. If you have employer health insurance through your job, you can keep both that insurance and Medicare, or you can decline Part B as described above.

Do I need to do anything to set up my Medicare coverage?

No. Your coverage is active automatically on the date listed in the Medicare Entitlement Notification. You do not need to call anyone or sign anything to turn it on. You can start using Medicare on that date even if your physical card has not arrived yet.

What happens if I move to a different state?

Your Medicare coverage follows you. Medicare is a federal program, so it works the same in every state. Update your address with Social Security so they can reach you, but your Medicare enrollment and coverage do not change when you move.