The Social Security Administration (SSA) is a Federal agency that administers two benefit programs for people with disabilities known as Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI). SSDI benefits are paid to individuals, and their dependents, who have been employed and have paid Social Security taxes through the Federal Insurance Contributions Act (FICA). Social Security provides SSDI benefits to those who cannot perform substantial work and who meet SSA's disability criteria. Eligibility for SSI is based solely on meeting specific income, resource, and disability eligibility criteria. A history of work or Social Security taxes is not considered in determining eligibility for SSI.