The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is the lead federal law enforcement agency charged with administering and enforcing federal laws related to the manufacture, importation, and distribution of firearms and explosives. Congress transferred ATF's enforcement and regulatory functions for firearms and explosives from the Department of the Treasury to the Department of Justice (DOJ) as part of the Homeland Security Act (P.L. 107-296). ATF is also responsible for investigating arson cases with a federal nexus, as well as criminal violations of federal laws governing the manufacture, importation, and distribution of alcohol and tobacco. Congress authorized appropriations for ATF in the Department of Justice Authorization Act of 2005 (P.L. 109-162) for FY2006 through FY2009; however, to date the 111th Congress has not considered legislation to reauthorize annual appropriations for DOJ or ATF. For three fiscal years, FY2008 through FY2010, Congress has provided about $49 million in program increases to address firearms trafficking. About $43 million of this funding has been allocated to Project Gunrunner, an ATF initiative to reduce gun trafficking across the Southwest border, or other projects to assist the government of Mexico. In the 110th Congress, the House passed a bill (H.R. 6028) that would have authorized appropriations over three years, for FY2008 through FY2010, of $73.5 million to increase ATF resources dedicated to stemming illegal gun trafficking into Mexico. In the 111th Congress, bills with similar authorizations have been introduced (S. 205, H.R. 495, H.R. 1448, and H.R. 1867). For FY2011, the Administration has requested $1.163 billion for ATF, an increase of 3.8% over the agency's FY2010 appropriation ($1.121 billion). For Project Gunrunner, the request includes $11.8 million to annualize 37 positions that were previously funded by the American Recovery and Reinvestment Act (P.L. 111-5). It also includes $1.2 million to enable ATF to coordinate state and local law enforcement efforts in the event of a national emergency and, thus, fulfill the Attorney General's Emergency Support Function #13 obligations under the National Response Framework. The FY2011 request assumes $35.2 million and 46 FTE positions in base adjustments, less offsets and other reductions. In March 2010, the House Commerce-Justice-State Appropriations subcommittee held a hearing on the ATF FY2011 budget submission. Members of the subcommittee raised questions about gun trafficking on the Southwest border, regulatory backlogs, violent crime impact teams, and inter-agency coordination on gang violence. Congress has passed and the President has signed into law the Prevent All Cigarette Trafficking Act (P.L. 111-154). This act grants ATF greater authority to inspect the businesses and records of "cigarette deliverers." In addition, under the Mérida Initiative, ATF has recently released a Spanish language version of its firearms trace request software (e-Trace 4.0) to Mexico, Guatemala, and Costa Rica, and has established a U.S.-Mexico ballistic information exchange capability under the National Integrated Ballistic Imaging Network program. Also of note, in the fall of 2009, the Department of Justice Office of Inspector General released three reports on ATF operations. The first examined ATF's Project Gunrunner. The second examined ATF's efforts to investigate contraband cigarette trafficking. The third examined ATF's concurrent jurisdiction with the Federal Bureau of Investigation for explosives-related investigations. This report complements CRS Report RL34514, The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF): Budget and Operations for FY2008, FY2009, and FY2010, and will be updated as needed.