SSDI and SSI disability benefits explained

The two main federal disability programs in the US are Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI). Both are run by the Social Security Administration and both use the same adult medical definition of disability, but they are funded differently and have completely different non-medical requirements.

SSDI: an insurance benefit based on your work record

SSDI is funded by the Social Security payroll taxes you and your employers have paid. To qualify you need enough work credits, and generally enough of them earned recently — the exact requirement depends on your age when you became disabled. SSDI is not means-tested, so savings and a spouse's income do not affect it. There is a waiting period of five full months from the established onset date before payments begin, and Medicare coverage generally begins 24 months after SSDI entitlement starts, with exceptions including ALS and end-stage renal disease.

SSI: a needs-based benefit with no work requirement

SSI pays monthly benefits to people who are 65 or older, blind, or disabled and who have limited income and resources. It requires no work history, which is why it is the route for people who became disabled young or who have not worked enough recently. It has strict income and resource limits, and in most states approval also brings Medicaid. Some people qualify for both SSDI and SSI at once — a concurrent claim — where a low SSDI payment is topped up by SSI.

The definition of disability

For adults, SSA defines disability as the inability to engage in substantial gainful activity because of a medically determinable physical or mental impairment that has lasted, or is expected to last, at least 12 months or to result in death. There is no partial or short-term disability benefit at federal level — SSA does not pay for temporary conditions. For children claiming SSI, the standard is marked and severe functional limitations rather than inability to work.

How a claim is decided

SSA works through a five-step sequential evaluation: whether you are working above the substantial gainful activity level, whether your impairment is severe, whether it meets or medically equals a listing in SSA's Listing of Impairments, whether you can still do your past relevant work, and whether you can adjust to other work given your age, education and work experience. Medical evidence is central, and SSA may send you to a consultative examination. The most common reason claims fail is insufficient medical documentation, not insufficient severity.

If your claim is denied

A large proportion of initial disability claims are denied, and many of those are later approved on appeal. The appeal path is reconsideration, then a hearing before an administrative law judge, then the Appeals Council, then federal court. You generally have 60 days from receiving each decision to move to the next stage. Keep treatment ongoing and documented throughout — gaps in treatment are among the most damaging things in a disability file. Representatives who handle SSA claims typically work on contingency, with fees capped and approved by SSA.

Working while receiving disability benefits

Both programs have work incentives designed to let people test their ability to work without immediately losing benefits — including the SSDI trial work period and extended period of eligibility, and for SSI the earned income exclusions and continued Medicaid under section 1619(b). The Ticket to Work program provides free employment support. These rules are genuinely complicated, and the free Work Incentives Planning and Assistance (WIPA) service exists specifically to explain how work would affect your own benefits before you commit to anything.