Many governments, businesses, and institutions are committing to net zero greenhouse gas emissions by 2050, a goal and process known as deep decarbonization. Achieving this goal in the United States requires a national, economy-wide transformation in energy production and use in five sectors: electricity, transportation, industry, land-based carbon sinks, and buildings. All of these sectors interact with planning for the built environment and land use, so planning scholars and practitioners have many opportunities to engage policymakers working on national-level decarbonization strategies. This article analyzes the consequences of deep decarbonization for the future speed, scale, scope, role, and relevance of planning.