Within a year of the terrorist attacks of September 11, 2001 and the subsequent anthrax mailings, two key pieces of legislation were passed by Congress that have a bearing on biosecurity. Signed into law seven weeks after 9/11, the USA PATRIOT Act, provided a sweeping set of legal, law enforcement, and national security provisions, including Section 817 which addressed "possession" of select agents for the first time. It established possession standards for bona fide research and requires assurances from research institutions that no "restricted persons" have access to such select agent research, including nonresident aliens from designated countries and US citizens with criminal records. In a broader sense, the Patriot Act makes it illegal for anyone in the United States to possess any biological agent, including any genetically engineered organism, for any inappropriate reason.

The second law, the Public Health Security and Bioterrorism Preparedness and Response Act, passed in June 2002 and added new requirements for listing of potentially dangerous biological agents and preventing unlawful access to agents during transfers. Included were provisions for background checks of individuals registered to possess select agents for research purposes.