This report provides a detailed description of the structural equations and their statistical attributes in the current version of the Food and Agricultural Policy Simulator (FAPSIM). FAPSIM is an annual econometric model of the U.S. agricultural sector. It estimates a simultaneous price-quantity equilibrium solution for a set of individual commodity models developed for beef, pork, dairy, chickens, eggs, turkeys, corn, oats, barley, grain sorghum, wheat, soybeans, and cotton. It also endogenously estimates farm production expenses, cash receipts, net farm income, Government deficiency and reserve storage payments, consumer price indexes for food products, and farmer participation in Government commodity programs.