A new National Renewable Energy Laboratory (NREL) guide on understanding power system model results is designed to improve decision-making in the electricity planning process by strengthening the dialogue between system planners and relevant stakeholders. It focuses on interpreting scenario results generated by power system planning models. These results are often used to inform integrated resource plans, which are long-term plans for a utility to meet future electricity requirements. This guide is designed to help State Energy Offices, Public Utility Commissions, intervenors in the planning process, or other stakeholders to better weigh in on the modeling methods or interpret the model results to improve decision-making. This guide can enable state decision-makers to ask the right questions, which can enable better understanding of results and key assumptions, data, and methods.