This report describes the FY2010 appropriations for the Department of Homeland Security (DHS). The Administration requested a net appropriation of $44.1 billion in budget authority for FY2010. This amounts to a $2.8 billion, or a 6.7% increase over the $41.2 billion enacted for FY2009 (not including supplemental funding). Total budget authority requested by the Administration for DHS for FY2010 amounts to $55.1 billion. Net requested appropriations for major agencies within DHS were as follows: Customs and Border Protection (CBP), $10,049 million; Immigration and Customs Enforcement (ICE), $5,458 million; Transportation Security Administration (TSA), $5,267 million; Coast Guard, $9,734 million; Secret Service, $1,490 million; National Protection & Programs Directorate, $1,319 million; Federal Emergency Management Administration (FEMA), $7,235 million; Science and Technology, $968 million; and the Domestic Nuclear Detection Office, $366 million. This report contains a detailed discussion of the Presidents budget request for DHS, but due to time constraints, the text does not include a detailed discussion of the House- or Senate-reported versions of the FY2010 bill. The tables reflect the House- and Senate-reported numbers. The House Committee on Appropriations reported its version of the FY2010 DHS Appropriations bill on June 12, 2009. This report uses House-reported H.R. 2982 and the accompanying committee report (H.Rept. 111-157) as the source for the House-reported numbers. The House-reported H.R. 2982 recommends a net appropriation of $44.0 billion for DHS for FY2010. This amounts to a $205 million decrease as compared to the Administrations request, and a nearly $2.8 billion increase as compared to the $41.2 billion enacted for FY2009 (not including FY2009 supplemental funding). The Senate Committee on Appropriations reported its version of the FY2010 DHS Appropriations bill on June 17, 2009. This report uses Senate-reported S.1298 and the accompanying committee report (S.Rept. 111-31) as the source for the Senate-reported numbers. The Senate-reported S.1298 recommends a net appropriation of $44.3 billion for DHS for FY2010. This amounts to a $97 million increase as compared to the Administrations request, and a nearly $3.1 billion increase as compared to the $41.2 billion enacted for FY2009 (not including FY2009 supplemental funding). This report will be updated to reflect congressional action.