Hi, if you worked and paid into S.S. you should be eligible for SSDI. However, SSI is incomed based and each state has it's cap. Don't know what your is but anyone there can tell you. So what I am saying is if you paid into ss enough quarters, you should be eligible for benefits. But since you are getting SSI it raises the question of SSDI or not. Is there an advocacy agency such as the office of equal opportunity near you? Make some call, write some letters and if it's not far, go to the social security office.