This testimony discusses our report on a national strategy for high-containment laboratories that deal with dangerous–pathogens also known as biosafety level-3 (BSL-3) laboratories and biosafety level-4 (BSL-4) laboratories–in the United States, which was released yesterday. The number of high-containment laboratories that work with dangerous biological pathogens have proliferated in recent years. In 2007, we reported on several issues associated with the proliferation of high-containment laboratories in the United States, including risks posed by biosafety incidents that have occurred in the past. The Federal Bureau of Investigation’s allegation in August 2008 that a scientist at the U.S. Army Medical Research Institute of Infectious Diseases was the sole perpetrator of the 2001 anthrax attacks raised additional concerns about the possibility of insider misuse of high-containment laboratory facilities, material, and technology. The public is concerned about these laboratories because the deliberate or accidental release of biological agents can have disastrous consequences by exposing workers and the public to dangerous pathogens. Highly publicized laboratory errors and controversies about where high-containment laboratories should be located have raised questions about whether the governing framework, oversight, and standards for biosafety and biosecurity measures are adequate. In this context, Congress asked us to address the following questions: 1. To what extent, and in what areas, has the number of high-containment laboratories increased in the United States? 2. Which federal agency is responsible for tracking the expansion of high-containment laboratories and determining the associated aggregate risks? 3. What lessons can be learned from highly publicized incidents at high-containment laboratories and actions taken by the regulatory agencies?