This study applies an intertemporal partial equilibrium model of the U.S. Forest and Agricultural sectors to assess the market, land use, and greenhouse gas (GHG) implications of biomass electricity expansion. Results show how intertemporal optimization procedures can yield different biomass feedstock portfolios and GHG performance metrics at different points in time. We examine the implications of restricting feedstock eligibility, land use change, and commodity substitution to put our results in the context of previous forest-only modeling efforts. Our results highlight the importance of dynamic considerations and forest and agricultural sector interactions on projecting the GHG effects of biomass electricity expansion in the U.S.