Written & reviewed by External Legal AI · Updated June 26, 2026
Social Security runs two disability programs, and people mix them up constantly. SSDI (Social Security Disability Insurance) is for people who paid into Social Security through payroll taxes and later became unable to work. SSI (Supplemental Security Income) is need-based — no work history required, but strict income and asset limits. Both use the same medical definition of disability, and one application can cover both at once.
SSDI eligibility depends on how much and how recently someone worked. The general benchmark is 40 work credits with 20 earned in the last 10 years, though younger workers qualify with fewer. The monthly benefit is based on the person's own earnings record, not on financial need.
SSI has no work-history requirement. Instead it looks at income and resources: countable assets generally must stay under $2,000 for an individual or $3,000 for a couple, with the house you live in and usually one vehicle excluded. The federal payment standard is set each year, and some states add a supplement on top.
Both programs use one definition: a medically determinable condition that prevents substantial gainful activity and has lasted, or is expected to last, at least 12 months or result in death. SSA evaluates claims against its listing of impairments plus what work, if any, the person can still do.
Applications can start online at ssa.gov, by phone at 1-800-772-1213, or at a local Social Security office. SSDI can usually be completed entirely online; SSI applications often finish with a phone or in-person interview. Applying promptly matters because SSDI back pay is limited by the filing date.
The strongest files have consistent medical records: treatment notes, test results, specialists' opinions about specific functional limits, a medication list with side effects, and a complete work history. Gaps in treatment are one of the most common reasons claims stall, so continuing care while the claim is pending makes a real difference to the record.
Initial decisions commonly take six months or more, and most initial claims are denied. That's the start of an appeals process with its own deadlines, not a final answer — many claims that lose on paper are approved later at a hearing.
More on this topic: the Benefits hub
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