This paper describes the regional extension of USAGE-ITC, a 500-order dynamic CGE model of the US that we are developing in collaboration with the International Trade Commission. With the regional extension, USAGE-ITC can project the effects on employment and output by state of policy and other shocks to the economy. The paper describes the theory and data underlying the regional extension, and provides an illustrative application concerned with the effects of elimination of US restraints on imports. In CGE modeling there are two broad approaches to generating regional results: bottoms-up and tops-down. Our approach here is tops-down with emphasis on the estimation of inter-regional flows of goods and services. As explained in the paper, the tops-down approach is adequate for analysis of economy-wide shocks such as changes in Federal policies. Bottoms-up modeling will be required for analysis of shocks in which the essence is a change in relative costs across regions.