Supplemental Security Income (SSI) is different from other disability benefits in that it is not dependant on having paid into the social security systems and it is dependant on assets and income.

SSI benefits are available for both adults and children. The amount of benefits paid each month is based on the individuals income or in the case of children based on household income. 

It should be noted that people are often prompted to apply for SSI while trying to obtain a medical card. While these are separate programs the criteria for Medicaid is such that if a person can prove eligibility for SSI then the person has met the  eligibility requirements for Medicaid.

The reverse is not true, however. In the event a person wishes to obtain a medical card and has been turned down for SSI it is prudent to pursue a  separate Medicaid claim as there are other criteria under which you may be eligible.