To begin the process, the family needs to complete an application, available at the local Social Security Administration (SSA) office, by mail, or over the internet (www.ssa.gov).
Someone from SSA will interview the parent (or other relative or guardian of the child) to establish that the family’s income and resources meet the SSI limits.
A representative from SSA will next gather medical information, and other important information about the child’s disability, and based on this information will decide whether the child is eligible for SSI.
Before deciding whether the person applying for SSI is disabled, SSA considers a person's income for determining eligibility and for calculating the amount of an individual's benefits. In general, the more a person has in income, the lower the SSI benefit will be. For children, SSA has rules that count (or deem) a portion of the parent's income to the child applying for SSI.