The objective of this paper is to detailed supply relationships for nitrous oxide (N2O) emissions from U.S. agriculture for the purpose of conducting policy-sensitive emissions modeling of this greenhouse gas. The basic tool used is the emissions framework of the Intergovernmental Panel on Climate Change (IPCC) Phase II guidelines developed by the IPCC and Organization for Economic Cooperation and Development (OECD) for national emissions inventories. The inventory method has been modified based on the results of an updated literature review and analysis. The supply relationships developed in this project are used to estimate emissions of N2O for U.S. agriculture through the year 2080 under baseline conditions and a policy to restrain emissions growth.