There is often confusion about Social Security and Supplemental Security Income (SSI) because you apply for both programs with the Social Security Administration. But, the programs are different. The Social Security benefit programs are “entitlement” programs. This means that workers, employers and the self-employed pay for the benefits with their Social Security taxes. The taxes that are collected are put into special trust funds. You qualify for these benefits based on your work history (or your spouse or parent). The amount of the benefit is based on these earnings.
SSI is a needs-based program for people with limited income and resources. Resources are assets or things that you own. The program is paid for by general tax revenues -- not from the Social Security trust funds. The benefit amount is based on Federal and State laws which take into account where you live, who lives with you and what income you receive.