This report aims to assist the Commission and other stakeholders at this critical, early moment in gas distribution system transition planning. It draws on existing research and adds new data and analysis on several key topics, such as costs of the gas distribution system, the fragility of gas utility business models to competition from new electric technologies, the hurdles to substituting fuels like renewable natural gas (RNG) or hydrogen for fossil methane gas, and the benefits and pitfalls of pathways studies. This report also offers a synthesis of these and other factors in a scenario-based discussion of potential approaches to gas distribution system transition. It is organized in four sections.