[Excerpt] Social Security Disability Insurance (SSDI) and Veterans Disability Compensation (VDC)— administered by the Social Security Administration (SSA) and the Department of Veterans Affairs (VA) respectively—are two of the largest federal disability programs, but strongly differ along several dimensions, including the populations served, how each program defines a “disability,” as well as varying eligibility requirements. This report provides a description and comparative analysis of the SSDI and VDC programs. These issues will be of particular interest to Congress because of the expected increase in the numbers of SSDI and VDC claims. The recent economic decline and aging baby-boomers have continued to place a strain on SSA’s resources. The aging of the veteran population and expansion of presumptive conditions policies have contributed to the increase in VDC claims.