CBO Economic and Budget Issue Brief: Federal Funding for Homeland Security: An Update [open pdf - 336KB]
"The terrorist attacks of September 11, 2001, heightened Congressional and public interest in federal spending for homeland security. Funding for that purpose is divided among more than 200 appropriation accounts within the federal budget and involves many different functional areas of the government. Much of the funding resides within accounts that primarily finance programs not classified as homeland security activities. That accounting arrangement makes it difficult for budget analysts to identify and track homeland security spending. Current data on funding for homeland security are provided in annual reports to the Congress by the Administrations Office of Management and Budget (OMB). On the basis of those reports, the Congressional Budget Office (CBO) estimates that federal resources dedicated to homeland security will total $49.1 billion in 2005 - nearly triple the amount allotted for that purpose before September 11. For fiscal year 2006, the Administration has proposed a slight increase in homeland security funding, to $49.7 billion."
Congressional Budget Office: http://www.cbo.gov