This paper documents the basic Computable General Equilibrium (CGE) model of the U.S. economy developed at the Economic Research Service (ERS), USDA. The paper both describes the model equations in detail and how the model is "benchmarked" to a base data set. The paper also lists the computer program used to implement the model. The objective of the CGE work program at ERS is to provide a multisectoral framework for analyzing the effect of changes in agricultural policies and exogenous shocks on the farm sector, on the rural economy, on related nonagricultural sectors, and on the rest of the economy. The basic model has provided a starting point for a variety of extensions and applications exploring a number of policy issues. To date, work has largely focused on issues of agricultural trade policy and the effect of alternative domestic policies.