For years, the Social Security Administration (SSA) has experienced processing delays and significant backlogs of disability claims. At the end of fiscal year 2006, some 1.5 million disability claims were awaiting a decision. About 576,000 of these claims were backlogged-exceeding the number of claims that should optimally be pending at year-end. In response to the congressional request, GAO (1) examined trends in disability claims backlogs and the time required for SSA to decide a claim, (2) identified key factors contributing to the backlogs and processing times, and (3) described the steps SSA is taking to reduce them. To address these issues, GAO analyzed SSA administrative data, conducted an extensive literature review, interviewed SSA officials as well as key program personnel, and conducted site visits in three SSA regions.