SSI vs SSDI: 8 key differences

Direct answer: SSI is a needs-based program funded by general tax revenue with strict income and resource limits and no work-credit requirement; SSDI is an insurance program funded by payroll taxes that requires work credits and pays based on your earnings record.

What is the difference between SSI and SSDI?

The two programs share the same medical standard (SSA's five-step disability evaluation), but they are otherwise very different in eligibility, funding, benefit amount, health-insurance link (Medicaid for SSI, Medicare after 24 months for SSDI), and family benefits. You can qualify for both at the same time — this is called 'concurrent' benefits.

Where does this rule live in SSA's regulations?

SSA publishes the SSI eligibility rules in the SSI Eligibility page on ssa.gov and the annual 2026 SSI figures at ssa.gov/oact/cola/SSI.html. When SSA's public page and this article differ, ssa.gov controls.

What if I'm not sure I qualify?

Apply anyway. SSA determines eligibility on the facts of your case, and application itself protects the earliest possible filing date. There is no penalty for applying and being denied.