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

You do not need to do anything to enroll. Social Security will register you for Medicare Part A (hospital insurance) and Part B (medical insurance) automatically once you have received SSDI payments for 24 consecutive months. The 24-month clock starts from the month your first SSDI check arrives, not from the month you applied.

Your Medicare card will arrive in the mail about three months before your coverage begins. The coverage itself starts on the first day of the 25th month of your SSDI payments. For example, if your first SSDI check was in January 2023, your Medicare coverage would start on January 1, 2025.

You will receive a notice from Social Security in the mail explaining your Medicare coverage and what to expect. Keep this notice with your Medicare card once it arrives. You do not pay a premium for Part A, but Part B has a monthly premium that Social Security will deduct from your SSDI check.

Key Takeaways

  • Medicare Part A and Part B begin automatically after 24 months on SSDI; you do not need to take any action to enroll.
  • Your Medicare card arrives about three months before coverage starts, and coverage begins on the first day of your 25th month receiving SSDI.
  • Part A has no premium, but Part B has a monthly cost that Social Security deducts directly from your SSDI payment.
  • You can add Part D (prescription drug coverage) or a Part C plan (Medicare Advantage) during the enrollment period after your Part A and Part B coverage begins.
  • If you miss the chance to enroll in Part D when first may be able to access, you may face a permanent penalty on your premiums.

What Part A and Part B cover

Part A covers inpatient hospital stays, skilled nursing facility care after a hospital stay, hospice care, and some home health services. You pay nothing for Part A premiums because you have already paid into Medicare through payroll taxes during your work history.

Part B covers doctor visits, outpatient services, lab tests, X-rays, and some preventive care. Part B has a monthly premium that varies by income. For 2024, the standard Part B premium is $164.90 per month, but higher-income beneficiaries pay more. Social Security will tell you your exact premium amount when they send your Medicare notice.

Neither Part A nor Part B covers dental, vision, or hearing services. If you need those services, you can purchase a separate dental, vision, or hearing plan through a private insurance company, though these are not part of Medicare.

Adding Part D prescription drug coverage

You are not automatically enrolled in Part D (prescription drug coverage). You must choose a plan and enroll during your enrollment period. Your initial enrollment period begins three months before your Part A and Part B coverage starts and ends three months after it starts — a total window of seven months.

If you do not enroll in Part D during this window and you do not have other creditable prescription drug coverage, you will owe a permanent late enrollment penalty. The penalty is calculated as 1% of the national average Part D premium for each month you were not enrolled. This penalty stays on your premiums for as long as you have Part D coverage.

To enroll in Part D, visit Medicare.gov, call 1-800-MEDICARE, or visit your local Social Security office. You will choose from several plans available in your area. Each plan covers different drugs and has different costs. Compare plans before you choose, because switching plans is only possible during the annual enrollment period (October 15 through December 7).

Understanding Part C (Medicare Advantage) as an alternative

Part C, also called Medicare Advantage, is an alternative to Original Medicare (Part A and Part B). With Part C, a private insurance company contracts with Medicare to provide your Part A and Part B coverage, usually with added benefits like dental or vision. Part C plans often have lower or zero premiums than Part B alone, but they typically have network restrictions — you must use doctors and hospitals in the plan's network.

You can enroll in a Part C plan during the same seven-month initial enrollment period as Part D. If you choose a Part C plan, you do not need to enroll separately in Part B, because Part C includes it. However, you still need to decide about Part D prescription drug coverage, because most Part C plans do not include it.

You can switch between Original Medicare and Part C plans only during the annual enrollment period or if you move out of your plan's service area. Choosing Part C is a significant decision, so compare what doctors and hospitals are in each plan's network before you enroll.

What happens to your coverage if you work or your SSDI ends

If you return to work and your SSDI payments stop, your Medicare coverage does not stop automatically. You keep Part A and Part B for as long as you remain may have access to to them under the rules. However, if you earn above the substantial gainful activity (SGA) limit, your SSDI will end, and your Medicare will end nine months later (with a three-month grace period built in).

If your SSDI ends for a reason other than work — for example, a medical review determines you are no longer disabled — your Medicare will end at the same time your SSDI ends, unless you are age 65 or older. At age 65, you become may have access to to Medicare based on age rather than disability, so your coverage continues.

If you know your SSDI will end, contact Social Security at least one month before to understand how your Medicare will be affected. You may be able to purchase Medicare coverage on your own if you lose it, but the cost will be higher than what you pay as an SSDI beneficiary.

Costs you will pay for Medicare on SSDI

Your Part B premium is deducted from your SSDI check each month. The amount depends on your income from the previous two years. If your income is below a certain threshold, you pay the standard premium. If your income is above that threshold, you pay an income-related monthly adjustment amount (IRMAA), which is higher.

In addition to premiums, you will pay out-of-pocket costs when you use services. Part A has a deductible for hospital stays. Part B has an annual deductible and coinsurance (a percentage of the cost you pay after the deductible). Part D has a deductible, copayments, and coinsurance that vary by plan.

If your income is very low, you may be able to get help paying these costs through programs like Medicaid or the Medicare Savings Program. Contact your state Medicaid office or call 1-800-MEDICARE to find out whether you may have access to.

Frequently Asked Questions

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

Your Medicare coverage does not change. You keep the same Part A and Part B coverage you have as an SSDI beneficiary. At age 65, you become may have access to to Medicare based on age rather than disability, so your coverage continues even if your SSDI ends for any reason.

Can I enroll in Part D after the initial enrollment period ends?

Yes, but only during the annual enrollment period (October 15 through December 7) or if you have a may have access to life event like losing other drug coverage. If you enroll late without a may have access to reason, you will owe a permanent penalty on your Part D premiums.

Do I have to take Part B when Medicare starts?

Part B is not automatic — you must actively enroll or decline it. However, if you do not enroll when first may be able to access and you do not have other creditable coverage, you will owe a permanent late enrollment penalty of 10% of the Part B premium for each year you were not enrolled.

What if I cannot afford the Part B premium?

If your income is low, you may may have access to for the Medicare Savings Program, which helps pay Part B premiums and other out-of-pocket costs. Contact your state Medicaid office or call 1-800-MEDICARE to explore. may be able to access and benefit amounts vary by state.

Can I switch from Part C back to Original Medicare?

Yes, but only during the annual enrollment period (January 1 through March 31). If you switch outside this window, you may not be able to enroll in a Medigap supplemental plan without waiting periods or exclusions for pre-existing conditions.