In case of a physical or mental (psychological) disability that makes a person unable to perform any work he/she is suited for (based on age, educational and work background) and if this disability is expected to last for a year or more, or to result in death, such person will be regarded disabled for Social Security purposes.
There are four different benefit programs for disabled people administered by Social Security: Disabled Adult Child Benefits (DAC), Disabled Widows and Widowers benefits (DWB), Supplemental Security Income and Social Security Disability Insurance (SSDI). Still, each program has the same medical requirements to consider person as being disabled and the same disability determination process.
Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) programs are usually confused by many people. These two programs have the following differences:
If you are “insured”, SSDI will pay benefits to you and some of your family members (this program is funded by Social Security taxes you have paid during work). After receiving two years of benefits an SSDI-eligible person will be enrolled in Medicare automatically.
In case of SSI you are paid benefits according to your financial needs no matter if you have ever worked or not. As a Federal income supplement program SSI is funded by general tax revenues (but not Social Security taxes). A person is automatically qualified for Medicare if eligible to receive SSI (no need to wait two years).