Yes, most SSDI recipients must enroll in Medicare automatically

If you receive SSDI benefits, Medicare enrollment happens automatically after you have been on SSDI for 24 months. You do not choose whether to enroll — Social Security signs you up. This is true whether you are 65 or younger. The 24-month waiting period starts the month your SSDI payments begin, not the month you applied.

You will receive a Medicare card in the mail about a month before your coverage starts. The card shows your Medicare number, which is usually your Social Security number followed by a letter. You do not pay a premium for Part A (hospital insurance) because you have already paid into Social Security through payroll taxes.

Part B (medical insurance) has a monthly premium that comes out of your SSDI check automatically, unless you choose to decline it. Most people keep Part B because the premium is low compared to what you would pay on your own, and it covers doctor visits and outpatient care.

Key Takeaways

  • Medicare Part A starts automatically after 24 months on SSDI, with no premium charged to you.
  • Part B premium is deducted from your SSDI payment each month unless you actively decline it when you receive your Medicare card.
  • You cannot opt out of Part A, but you can refuse Part B if you have other coverage or choose to pay out of pocket.
  • If you turn 65 while on SSDI, your Medicare enrollment follows the same 24-month rule — it does not change at age 65.

What happens during the 24-month waiting period

During the first 24 months of SSDI, you are not yet enrolled in Medicare. If you need health coverage during this time, you may be able to use Medicaid instead. Medicaid rules vary by state — some states cover all SSDI recipients automatically, while others require you to meet additional income or resource limits. Contact your state Medicaid office to find out what you may have access to for.

Some people purchase private health insurance during the waiting period, either through an employer, a spouse's plan, or the health insurance marketplace. If you have access to employer coverage, you may want to keep it even after Medicare starts, because employer plans and Medicare can work together to cover more of your costs.

Part A and Part B: what you pay and what they cover

Part A covers hospital stays, skilled nursing facility care, hospice, and some home health services. There is no monthly premium. You may owe a deductible when you enter the hospital, but this amount resets each year.

Part B covers doctor visits, outpatient surgery, lab tests, imaging, and some preventive care. The monthly premium changes each year and is deducted from your SSDI payment. In 2024, the standard premium is $164.90 per month, but your actual premium may be higher or lower depending on your income. If you decline Part B when you first become may be able to access, you may pay a penalty if you enroll later.

You can also choose to enroll in Part D (prescription drug coverage) through a private insurance company. Part D is not automatic — you must select a plan. If you do not enroll in Part D when you first become may be able to access, you may pay a penalty for each month you go without it.

Can you decline Medicare or keep other coverage instead

You cannot decline Part A. It starts automatically after 24 months on SSDI, and there is no way to opt out. However, you can decline Part B by returning a form to Social Security before your coverage begins. If you have employer coverage or other insurance that meets Medicare's standards, declining Part B may make sense — but understand that you cannot change your mind without paying a penalty.

If you have employer health insurance through your own job or a spouse's job, you can keep it alongside Medicare. The two plans coordinate, with Medicare paying second after your employer plan pays first. This is called coordination of benefits. Tell your employer's benefits office that you have Medicare so they can process claims correctly.

Veterans with VA health benefits can keep using the VA even after Medicare starts. You do not have to choose between them — you can use both. However, the VA and Medicare do not coordinate the way employer plans do, so you may need to tell each provider what other coverage you have.

What changes if you are under 65

SSDI recipients under 65 go through the same Medicare enrollment process as anyone else — after 24 months on SSDI, you are enrolled in both Part A and Part B. Your age does not change this timeline. You will be younger than the typical Medicare beneficiary, but you have the same coverage and the same rules.

Some younger SSDI recipients worry about the cost of Part B or feel they do not need it. If you are healthy and have no regular medical expenses, you might consider declining Part B. But if you later change your mind, you will pay a penalty of 10 percent of the standard premium for each year you were not enrolled. That penalty is permanent.

How to prepare before Medicare starts

About three months before your 24-month mark, Social Security will send you information about Medicare in the mail. Read this carefully — it explains your coverage options and tells you the exact date your Medicare starts. If you want to decline Part B, you must respond by the important date shown in the letter, or Part B will start automatically.

Before your Medicare card arrives, make a list of your current doctors and ask their offices whether they accept Medicare. Most do, but some do not. If your doctor does not accept Medicare, you will need to find a new one or pay out of pocket for their care. You can search for Medicare-accepting doctors on Medicare.gov.

If you are currently using Medicaid, contact your state Medicaid office to ask what happens when Medicare starts. In most states, you keep Medicaid as a secondary payer — it covers costs that Medicare does not, like copayments and deductibles. This combination is called Medicare-Medicaid or "dual may be able to access" status.

What to do if you disagree with automatic enrollment

If you believe you should not be enrolled in Medicare, or if you want to delay enrollment, you can contact Social Security to request an exception. These requests are rare and usually only granted if you have employer coverage that meets specific requirements. Call Social Security at 1-800-772-1213 to discuss your situation.

If you enrolled in Part B but want to cancel it later, you can request to be disenrolled during the annual enrollment period (October 15 to December 7 each year). However, if you disenroll and then want to re-enroll, you will owe the permanent penalty described above. Make this decision carefully.

Frequently Asked Questions

What if I have employer health insurance when Medicare starts?

You can keep both. Tell your employer's benefits office that you now have Medicare so they know to coordinate benefits. Your employer plan will pay first for covered services, and Medicare pays second. This often results in lower out-of-pocket costs than either plan alone.

Do I have to pay for Part A?

No. Part A has no monthly premium for SSDI recipients. You may owe a deductible when you use hospital services, but there is no ongoing cost for having the coverage.

What happens if I refuse Part B and then change my mind?

You can enroll in Part B during the annual enrollment period (October 15 to December 7), but you will pay a permanent 10 percent penalty on the standard premium for each year you were not enrolled. This penalty stays with you for life.

Can I use only Medicaid instead of Medicare?

No. Once you have been on SSDI for 24 months, Medicare enrollment is automatic and cannot be avoided. However, you can have both Medicare and Medicaid at the same time — Medicaid will help cover costs that Medicare does not pay.

Does turning 65 change my Medicare coverage?

No. If you are already on Medicare through SSDI, your coverage does not change when you turn 65. You keep the same Part A and Part B coverage. If you are not yet on SSDI when you turn 65, you would enroll in Medicare through regular retirement benefits instead.