Therapeutics and vaccines are available for only a fraction of biological threats, leaving populations vulnerable to attacks involving biological weapons. Existing U.S. policies to accelerate commercial development of biodefense products have thus far induced insufficient investment by the biopharmaceutical industry. In this article, we examine the technical, regulatory, and market risks associated with countermeasure development and review existing and proposed federal incentives to increase industrial investment. We conclude with several recommendations. To increase industry's engagement in biodefense countermeasure development, Congress should expand BioShield funding, giving HHS the flexibility to fund a portfolio of biodefense countermeasures whose revenues are comparable to those of commercial drugs. Congress should establish tradable priority review vouchers for developers of new countermeasures. A National Academy of Sciences or National Biodefense Science Board should formally evaluate incentive programs and a government-managed "Virtual Pharma," in which HHS contracts separate stages of research, development, and production to individual firms.