Despite growing interest in local food, modeling the economic contribution of this endogenous system is inherently problematic. We present a combined hypothetical extraction and import-substitution social accounting matrix model that overcomes these problems in a theoretically consistent and computationally feasible manner. The method can be applied broadly to many different definitions of a “local food system” and uses the same underlying method as traditional economic-base contribution models. We apply this model to the state of Idaho and compare the economic contribution of the local food system against the economic contribution of the export food system.