The Social Security Administration (SSA) provides Social Security Disability Insurance (SSDI) benefits to disabled persons of less than full retirement age and to their dependents. SSA also provides Supplemental Security Income (SSI) payments to disabled persons who are under age 65. For both programs, disability is defined as a medically determinable physical or mental impairment” that prevents an individual from engaging in any substantial gainful activity and is expected to last at least 12 months or result in death. As of December 2004, SSA was making disability payments to 10.8 million adults and children based on their own disability and 1.5 million dependents of disabled adults. In fiscal year (FY) 2005, SSA estimated it would process approximately 2.5 million initial claims for disability benefits, 25 percent more than in FY 2000. Assuming that an applicant meets the nonmedical requirements for eligibility (e.g., quarters of covered employment for SSDI; income and asset limits for SSI), the file is sent to the Disability Determination Services (DDS) agency operated by the state in which he or she lives for a determination of medical eligibility.