Since October 2003, Gerald Epstein has been Senior Fellow for Science and Security in the CSIS Homeland Security Program, where he works on issues including reducing biological weapons threats, improving national preparedness to respond to biological attack, and ameliorating potential tensions between the scientific research and national security communities. He came to CSIS from the Institute for Defense Analyses, where he had been assigned to the Defense Threat Reduction Agency. From 1996 to 2001, he worked at the White House Office of Science and Technology Policy (OSTP), serving for the last year in a joint appointment as Assistant Director of OSTP for National Security and Senior Director for Science and Technology on the National Security Council staff. His responsibilities at OSTP included technologies to counter terrorism and to protect the nation’s critical infrastructures; chemical and biological weapons nonproliferation and arms control; missile defense; strategic arms control; the nuclear weapon stockpile stewardship program; export controls; and national security/emergency preparedness telecommunications.

From 1983 to 1989 and again from 1991 until its demise in 1995, he worked at the Congressional Office of Technology Assessment, where he directed a study on the proliferation of weapons of mass destruction and worked on other international security topics. From 1989 to 1991, he directed a project at Harvard University's Kennedy School of Government on the relationship between civil and military technologies. He has also served as visiting lecturer in public and international affairs at Princeton University's Woodrow Wilson School.

Dr. Epstein is a Fellow of the American Physical Society, a member of the editorial board for the journal Biosecurity and Bioterrorism, and a member of the Biological Threats Panel of the National Academy of Sciences’ Committee on International Security and Arms Control.