The primary mission of the Department of Homeland Security (DHS, the Department) is to "prevent terrorist attacks within the United States, reduce the vulnerability of the United States to terrorism, and minimize the damage, and assist in the recovery from terrorist attacks that do occur in the United States. Since its inception in 2003, DHS has had an intelligence component to support this mission and has been a member of the U.S. Intelligence Community (IC). Following a major reorganization of the DHS (called the Second Stage Review or "2SR") in July 2005, former Secretary of Homeland Security, Michael Chertoff established a strengthened Office of Intelligence and Analysis (I&A) and made the Assistant Secretary for Information Analysis (now Under Secretary for Intelligence and Analysis) the Chief Intelligence Officer for the Department. He also tasked I&A with ensuring that intelligence is coordinated, fused, and analyzed within the Department to provide a common operational picture; provide a primary connection between DHS and the IC as a whole; and to act as a primary source of information for state, local and private sector partners. Today, the DHS Intelligence Enterprise (DHS IE) consists of I&A, two headquarters elements supported by I&A, and the intelligence elements of six DHS operational components: U.S. Customs and Border Protection (CBP), U.S. Immigration and Customs Enforcement (ICE). U.S. Citizenship and Immigration Services (USCIS), the Transportation Security Administration (TSA), U.S. Coast Guard (USCG), and U.S. Secret Service (USSS). Congress made information sharing a top priority of the Department's intelligence component in the Homeland Security Act of 2002 and underscored its importance through the Intelligence Reform and Terrorism Prevention Act of 2004. Since the 2SR reorganization, Congress imposed additional requirements for intelligence analysis; information sharing; department-wide intelligence integration; and support to state, local, tribal governments, and the private sector through the Implementing Recommendations of the 9/11 Commission Act of 2007. On February 11, 2010, the Senate confirmed President Obama's selection of Caryn Wagner to serve as Under Secretary for Intelligence and Analysis. As she assumes responsibility for the DHS IE, Congress will likely be interested in the progress of integration of the Department's intelligence components and the quality and relevance of the intelligence DHS IE produces for front line law enforcement and security officials who are responsible for protecting America and its people. In February, DHS produced its first Quadrennial Homeland Security Review (QHSR), a comprehensive assessment outlining its long-term strategy and priorities for homeland security and guidance on the Department's programs, assets, capabilities, budget, policies, and authorities. The next step in the Department's QHSR process is to conduct a "bottom-up review" to systematically link strategy to program to budget. The results of that review will be particularly important as Congress considers an authorization bill for DHS. This report provides an overview of the DHS IE both at headquarters and within the components. It examines how DHS IE is organized and supports key departmental activities to include homeland security analysis and threat warning; border security; critical infrastructure protection; support to, and the sharing of information with, state, local, tribal, and private sector partners. It also discusses several oversight challenges and options for Congress to consider on these issues.