Social Security Income (SSI) vs. Social Security Disability Insurance (SSDI)

Published October 1, 2020

While both Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) programs provide financial benefits to individuals with disabilities, the eligibility criteria for each program have significant differences. Though often incorrectly discussed as interchangeable programs, perhaps because both are administered by the Social Security Administration (SSA) and medical eligibility is the same for each, SSI and SSDI are in fact very different.

As a threshold matter, an individual will only be eligible for either program if they meet the Social Security definition of disability:

  • The individual can’t perform the work done previously;
  • The SSA determines that the individual is unable to adapt to other work due to the medical condition; and
  • The disability has or is anticipated to last for at least a year or to cause death.

Unlike other programs, SSI and SSDI benefits are only payable to those who are deemed completely disabled in regards to performing work. There are no available benefits based on partial or short term disability.

The primary difference between SSI and SSDI is that SSI benefits are designed for low income individuals without the requisite work history to qualify for SSDI. In turn, SSDI, much like Social Security benefits generally, is designed for workers who have accumulated a designated amount of work credits.

What is SSI?

The SSI program is based solely upon need, as determined by the subject individual’s income and assets. Importantly, benefits are not paid from the Social Security Trust Fund but are funded through U.S. Treasury general funds. SSI is often referred to as a "means-tested program", to make clear that the program is not tied at all to one’s work history.

Financial need is the sole basis for eligibility. To meet the SSI requirements, an otherwise medically qualifying individual must have less than $2,000 in assets (or $3,000 for a couple) and a limited income. The income limit for SSI, which is also the SSI federal benefit rate (FBR) for 2020, is $783 per month for an individual and $1,175 per month for a couple.

What is SSDI?

Social Security Disability Insurance, like Social Security benefits generally, is funded through payroll taxes. Unlike SSI participants, SSDI recipients are treated as insured based on having worked for a designated number of years, during which work history recipients made regular contributions to the Social Security trust fund with payment of FICA Social Security taxes. SSDI applicants must be under 65 years of age and have earned a certain number of work credits. After receiving SSDI benefits for two years, the individual with disabilities will become eligible for Medicare.

Under SSDI, a disabled person's spouse and children dependents may also receive partial dependent benefits which are called auxiliary benefits. Only individuals over the age of 18 however can receive the actual SSDI disability benefit.

Who makes an eligibility determination?

Both SSI and SSDI programs are administered by the Social Security Administration. Social Security field offices process applications for both programs and these offices are responsible for making all nonmedical eligibility decisions including verifying income, resources, and living arrangements. State agencies referred to as Disability Determinations Services (DDS) are responsible for making the initial medical eligibility determinations and will base these decisions on the existing medical data provided by the applicant unless additional information is requested. DDS psychological consultants and disability examiners make the medical eligibility determination which is then sent back to the initial Social Security field office for a final resolution.

It is possible for an individual to qualify for benefits under both the SSI and SSDI programs. This would occur when an applicant has both the requisite limited income and assets for SSI and also has a sufficient work history to qualify for SSDI.

An adult with a disability can apply online for SSI and for SSDI benefits at any age. SSI applications cannot be made online however for people who are applying for anyone under the age of 18 with a disability or for a non-disabled person age 65 or over. These persons will need to visit their local Social Security office or call 1-800-772-1213 (TTY 1-800-325-0778).