Renewable bioenergy offers an alternative to fossil fuels for transportation and electric power, the two highest GHG-emitting sectors in the United States. Bioenergy feedstocks are cultivated crops, agricultural and forest residues, algae, sewage and livestock manures, and other organic materials. Feedstock selection and cultivation begins the bioenergy supply chain, followed by handling, processing and distribution, and, eventually, end use conversion, producing fuels to power motor vehicles and generate electricity. To achieve deep decarbonization across the U.S. economy, reducing carbon emissions at every stage of the bioenergy supply chain is paramount. As the chapter explains, there are at least four primary pathways for legal reform of the bioenergy feedstocks sector: land use prescriptions that preserve and expand carbon sinks and that ensure feedstocks are cultivated consistent with decarbonization objectives; subsidy programs that create value in land’s carbon sink potential and shape cultivation techniques consistent with decarbonization objectives; renewable energy mandates that stipulate credit for feedstocks on certification of approved cultivation methods and land use change criteria; and direct regulation of bioenergy end uses conditioned on feedstock cultivation processes. Although nationwide policy approaches would be most effective on the 2050 time horizon, policies along these pathways may be pursued independently at the federal, state, and local levels, and in some instances via private environmental governance mechanisms. Accordingly, the goal of deep decarbonization warrants legal innovation and reform wherever politically feasible.