What is the purpose of a Plan to Achieve Self Support? It gives the person extra SSI to pay for food and shelter so they can use their other income or resources to pay for vocational expenses. It allows any expense a person pays for that is related to impairments they have to be excluded when calculating the SSI amount. It allows people with disabilities who are under age 22 and are regularly attending school have some of their earnings not count against their SSI benefit Ensures Medicaid will continue when a person's SSI drops to $0