The Social Services Block Grant (SSBG) is a flexible source of funds that states use to support a wide variety of social services activities. States have broad discretion over the use of these funds. In FY2010, the most recent year for which expenditure data are available, the largest expenditures for services under the SSBG were for child care, foster care, and special services for the disabled. Since FY2002, annual appropriations laws have funded the SSBG at its authorized level of $1.700 billion. However, SSBG appropriations for each of FY2013-FY2015 have been subject to sequestration, a spending reduction process by which budgetary resources are canceled to enforce budget policy goals. The FY2015 operating level for the SSBG is roughly $1.576 billion post-sequester. This is $124 million (7.3%) less than the SSBG's FY2015 pre-sequester funding level of $1.700 billion and $2 million (0.1%) less than the SSBG's FY2014 post-sequester operating level of $1.578 billion. In addition to annual appropriations, the SSBG occasionally receives supplemental appropriations to assist states and territories in responding to natural disasters. Most recently, the SSBG received supplemental funding of $474.5 million (post-sequester) in FY2013 to support states affected by Hurricane Sandy. (These funds were in addition to the $1.613 billion, post-sequester, appropriated in the FY2013 annual appropriations law.) Annual appropriations laws since FY2001 have included a provision allowing states to transfer up to 10% of their Temporary Assistance for Needy Families (TANF) block grants to the SSBG. The SSBG is permanently authorized in Title XX-A of the Social Security Act (SSA). The 111th Congress amended Title XX of the SSA in the health care reform legislation signed into law by President Obama on March 23, 2010, the Patient Protection and Affordable Care Act (ACA; P.L. 111-148). This law inserted a new subtitle on elder justice into Title XX, which was itself re-titled as Block Grants to States for Social Services and Elder Justice. The health reform law also amended Title XX by establishing two demonstration projects to address the workforce needs of health care professionals and a new competitive grant program to support the early detection of medical conditions related to environmental health hazards. The purpose of this report is to provide background and funding information about the SSBG; the report does not provide detailed information on other programs authorized within Title XX of the SSA.