Nearly half a million miles of oil and gas transmission pipeline crisscross the United States. The nation's pipeline industry has made substantial investments to protect these systems and respond to the possibility of terror attacks. However, U.S. pipelines are inherently vulnerable because of their number and dispersion. Due to the essential role pipelines play in our economy, Congress is examining the adequacy of federal pipeline security efforts. The Transportation Security Administration (TSA), within the Department of Homeland Security (DHS), is the lead federal agency for security in all modes of transportation including pipelines. The agency oversees industry's identification and protection of critical pipeline assets through security reviews, risk assessment and inspections. The Office of Pipeline Safety (OPS), within the Department of Transportation (DOT), is the lead federal regulator of pipeline safety. While TSA and the OPS have distinct missions, pipeline security and safety are intertwined. There are questions about the appropriate division of responsibility between the agencies and about the resources they will have for mandated security activities. As the lead agency for pipeline security, TSA expects pipeline operators to maintain security plans based on security guidance initially circulated in 2002. TSA also plans to issue pipeline security regulations, although it is unclear if and when it will do so. This agency also intends to issue new analytic models to help operators identify critical facilities and assess vulnerability to terrorist attack. In 2003, TSA inspected 24 of the largest 25-30 pipeline operators to review their security practices and collect critical asset data. TSA found that nearly all of these operators had met or exceeded minimum security guidelines. All but two of the 24 operators also provided TSA with their security plans and critical infrastructure information. The OPS joined TSA on approximately one-third of these inspections and expects a continued security role. The agencies have no formal cooperative agreement defining responsibilities and at this point do not think they need one. Industry and government agencies generally assert that efforts to promote U.S. pipeline security are on the right track. Nonetheless, TSA's current funding for pipeline security will provide only limited capability for inspections and enforcement of any future regulations. The President's FY2005 budget request does not include a line item for TSA's pipeline activities; they will be funded from the agency's general operational budget. In addition to appropriations issues, Congress is considering several policy concerns: Operators believe they need more specific federal threat information to improve security decisions. Many operators also believe they need clear and stable definitions of what constitutes a "critical" asset. Finally, operators are concerned about potentially redundant, conflicting regulatory regimes under TSA and the OPS. This report will be updated as events warrant.