Public Guide
SSDI and SSI: A General Comparison
A plain-language comparison of Social Security Disability Insurance and Supplemental Security Income.
SSDI and SSI both use SSA's disability framework, but they are different programs. SSA can screen an application for one or both programs and makes the actual eligibility decision from the complete record.
| Topic | SSDI | SSI |
|---|---|---|
| Program type | Social insurance | Needs-based assistance |
| Work credits | Required under age-dependent rules | Not required |
| Payment basis | Covered earnings record | Federal benefit rate, reduced by countable income |
| Resource limit | No general program resource limit | Countable-resource limit applies |
| Health coverage | Medicare under program timing rules | Medicaid rules vary by state |
Disability Standard
For adults, both programs generally use the same medical disability standard. SSDI adds work-credit and insured-status requirements. SSI adds financial, residence, citizenship, and immigration-status requirements.
Different non-medical rules mean that a person may be eligible for one program, both programs, or neither. A short online comparison cannot make that determination.
Payments and Other Benefits
SSDI amounts are based on covered earnings. SSI begins with a federal benefit rate and applies countable-income and living-arrangement rules. Rates and limits change, so current SSA publications are more reliable than a fixed number in an article.
SSDI may lead to Medicare after the applicable waiting period. SSI-related Medicaid enrollment varies by state. Payments can also interact with workers' compensation, pensions, household income, and other public benefits.
Applications and Notices
SSA accepts applications online, by telephone, and through local offices. An award or denial notice identifies the program decided, the agency's reasoning, payment information if applicable, and available review rights.
Official Sources
This page provides a general program comparison. SSA determines eligibility and payment amounts under the rules in effect for the application.