According to a 2012 report released by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF), roughly 780 million people around the world lack access to clean drinking water and an estimated 2.5 billion people (roughly 40% of the world's population) are without access to safe sanitation facilities. The United States has long supported efforts to improve global access to clean water, sanitation, and hygiene (WASH). In 2000, for example, the United States signed on to the Millennium Development Goals, one of which includes a target to halve the proportion of people without access to safe drinking water and basic sanitation by 2015. In 2002, the United States also participated in the 2002 World Summit on Sustainable Development, which emphasized the need to address limited access to clean water and sanitation among the world's poor. The 109th Congress enacted legislation to advance these global goals through the Senator Paul Simon Water for the Poor Act of 2005 P.L. 109-121, (Water for the Poor Act)]. In March 2012, the U.S. Agency for International Development (USAID) announced that it had joined the Sanitation and Water for All partnership-a coalition of governments, donors, civil society and development groups committed to advancing sustainable access to clean drinking water and sanitation. Congressional support for the act was motivated, in part, by calls to augment funding for WASH programs and improve the integration of WASH activities into broader U.S. foreign aid objectives and programs, as well as global health efforts. The act called for USAID to bolster support for WASH programs, further synthesize WASH activities into global health programs, and contribute to global goals to halve the proportion of people without access to clean water and sanitation by 2015. In the 111th Congress, the Senator Paul Simon Water for the World Act of 2010 was introduced, but not enacted. That bill would have amended the Water for the Poor Act and addressed several concerns observers raised regarding the Water for the Poor Act, particularly by creating senior leadership within USAID to address water and sanitation issues, assessing U.S. water and sanitation programs, and strengthening reporting requirements. A new bill, introduced in the 112th Congress as the proposed Water for the World Act (S. 641), awaits action by the Senate Committee on Foreign Relations. Several agencies contribute to U.S. efforts to improve global access to clean drinking water and sanitation, of which programs implemented by the Millennium Challenge Corporation (MCC) and USAID make up roughly 90%. In FY2010, for example, the United States invested $953 million on water and sanitation programs worldwide, including $898 million provided by USAID and MCC. Appropriations for water projects are provided to USAID annually, while MCC receives multi-year funding for its country compacts that include support for water projects. As such, spending by MCC on water projects may vary significantly from year to year and may not be requested annually. The President requested $302 million for USAID's water activities for FY2012 and Congress appropriated not less than $315 million for international water and sanitation programs through the FY2012 Consolidated Appropriations. The FY2013 request for USAID's water and sanitation efforts was slightly lower at $299.1 million. This report addresses congressional efforts to address limited access to clean drinking water and sanitation, outlines related programs implemented by USAID and MCC, and analyzes issues related to U.S. and international drinking water and sanitation programs that the 112th Congress might consider.