What are the differences between Social Security Disability Insurance Benefits (SSD or DIB) and Supplemental Security Income (SSI)?

While benefits may be payable under either or both SSD and SSI, the standard for disability is the same and eligibility for either or both programs is determined by the same process. In addition to proving disability, a claimant for Social Security Disability must show that he or she had worked long enough to be “insured”. An SSI claimant must have limited assets and income. There are other differences in the eligibility rules for the two programs.
There are three categories under which a person can qualify for disability payment: disabled workers under 65 who have paid enough into the Social Security system; persons disabled continuously since age 22 if one of their parents is deceased, disabled or retired; and a disabled widow or widower between the ages of 50 & 60 whose spouse was covered by Social Security at the time of death.