What’s the Difference between Social Security Disability Insurance & Supplemental Security Income?

The Social Security Administration (SSA) manages the Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI) programs. While both of these programs offer cash benefits for people with disabilities, the eligibility requirements for each are different.

What Is SSDI?

SSDI is funded through payroll taxes. To get SSDI, you must be an adult between the ages of 18 and 64 and have earned a certain number of “work credits” by working and paying into the Social Security system for a certain amount of time. After you receive SSDI for two years, you’ll become automatically eligible for Medicare.

Under SSDI, the spouse and children of a person with a disability are eligible to receive partial dependent benefits even if they don’t have a disability themselves.

Social Security disability benefits are paid after you have been disabled continuously throughout a period of five full calendar months. Disability benefits are paid beginning with the sixth full month after the date your disability began.  You’re not entitled to benefits for any month during this five-month waiting period. The amount of the monthly benefit after the waiting period is based upon how much you’ve earned while working.

What Is SSI?

SSI is a program that is strictly need-based, according to income and assets, and is funded by general fund taxes. To meet the SSI income requirements, you must have limited income and resources.

An adult or child who has a disability must meet all of the following requirements:

  • Have limited income;
  • Have limited resources;
  • Be a U.S. citizen or national or in one of certain categories of aliens; and
  • Live in the U.S. or Northern Mariana Islands.

The monthly payment is based strictly on financial need and varies up to the maximum federal benefit rate. Some states add money to federal SSI payments. Approval for benefits generally takes three to six months. Once you’re approved for SSI, you’ll get benefits retroactive to the date of your application.

If you have a disability which prevents you from working, and you appear to meet all other eligibility requirements, it is possible to get SSI earlier. Sometimes on the day you apply.

In most states, people who get SSI are automatically eligible for Medicaid.


Return to Disability.gov’s Guide to Disability Benefits.