The first requirement is that you must have paid into Social Security for a long enough period of time and in large enough dollar amounts to be considered "eligible". Next, you must not be "gainfully" employed. You must next be under a "disability" which has lasted or is expected to last 12 months. You must have a "disability" that is "severe" enough to keep you from doing your past job. All of the terms in quotations are legal terms may need explanation by an attorney familiar with Social Security Regulations.