This presentation reports on methods developed, within the U.S. Department of Energy program to enhance Carbon Sequestration in Terrestrial Ecosystems (CSiTE), for estimating the potential of terrestrial carbon sequestration options. No single model can simulate all the relevant processes and activities, therefore three models are used: EPIC, a crop growth simulation model; FASOMGHG, an economic model of U.S. forestry and agriculture; and SGM, an economic model used to compare the potential for terrestrial mitigation options with greenhouse gas mitigation options outside of agriculture. Sequestration of carbon in agricultural soils, through changes in crop tillage, is used as an example to demonstrate the flow of information from EPIC to FASOMGHG to SGM. Considerations at the crop management level are the rate of carbon sequestered per hectare of land, changes in crop yield, and changes in emissions of nitrous oxide through fertilizer application. FASOMGHG then allows a distinction between technical potential, economic potential, and competitive potential. Economic potential approaches technical potential as the carbon price increases. Competitive potential introduces competition for land across terrestrial mitigation options. Finally, SGM provides a strategic comparison, over time and by cost, across all major types of greenhouse gas mitigation options in the United States.