While there are many technicalities, including age, education and vocational skills, the general concept is that to be considered disabled by SSA, medical evidence must show that one is not able to perform any full time job, which is found in the national economy of the United States, for a period of time which lasts at least one year or will sooner result in death.
For adults, SSI uses the same strict SSD definition of disability. (If you were getting "Aid to Permanently and Totally Disabled" in December 1973, less strict standards may apply.) Since children are not required to work in America, a child’s SSI disability requires medical evidence which shows very severe limitations in the child’s ability to function.
Last Reviewed: March 31, 2018