A notable aspect of sustainability is its holistic and cross-cutting nature—it cannot be achieved by any single rule, statute or agency. Instead, sustainability must be institutionalized across the legal system and government as a whole. In this paper, we propose and examine five mechanisms for institutionalizing sustainability across the federal legal system: (1) an Executive Order on sustainability, (2) a sustainability impact assessment process, (3) a non-partisan Congressional Joint Committee on Sustainability, (4) a federal Sustainability Commission, and (5) a Sustainability Law Reform Commission. Each is modeled on an existing institution in the United States or another jurisdiction. We discuss and compare the advantages and disadvantages of each mechanism, and discuss how the mechanisms might best be used, singly or in combination, to institutionalize sustainability across the federal government.