This report examines current trends in the U.S. grain industry.  Many identity preservation (IP) grain systems have emerged recently, driven by a confluence of supply and demand factors.  IP grain requirements for specific production protocols, marketing channels, and quality assurance depend on whether the crops are trait-specific, non-GM (genetically modified), organic, or pharmaceutical.  Cost structures vary according to the relative importance of segregation and risk management.  High information management, greater market coordination, and frequent reliance on contracts characterize IP grains.  IP grain markets are also inherently riskier, with volatile supply, inelastic demand, and fluctuating price premiums.  Increasing grain differentiation is altering the marketing structure of the U.S. grain industry and creating possible roles for government policy, particularly in market facilitation, standard setting, and regulations affecting food safety and biosecurity.