Amazon WW Sustainability proposed a suite of carbon reduction goals in anticipation of the public release of Amazon’s carbon footprint in the fall of 2019. Shipment Zero was Amazon’s initial public goal to make 50% of all shipments net-zero carbon by 2030. Later, informed by its carbon footprint assessment, Amazon announced its goal to reach net-zero carbon across all of Amazon by 2040. According to the U.S. Department of Transportation, trucking is the largest contributor to national freight-related air pollution and its greenhouse gas emissions have increased five times faster than passenger travel emissions since 1990. Carbon reductions can be achieved by reducing the well-to-wheel emissions of vehicle operations, while zero-emissions targets specifically require vehicles with zero tailpipe emissions. This research evaluated the potential of renewable natural gas, hydrogen fuel cell electric, and battery electric vehicles to reduce the carbon footprint of heavy-duty diesel linehaul trucking. Research insight was based on an extensive literature review, the Argonne National Laboratory’s transportation emissions and economic modeling tools, academic and fuel-vendor interviews, and a summer internship on Amazon’s Transportation Sustainability team. Five criteria were determined to influence the fit of alternative powertrains for linehaul trucking: greenhouse gas reduction potential, vehicle availability, vehicle functionality, cost, and scalability. No one technology is a perfect decarbonization solution, and all powertrains require a facilitative market and policy environment. The resultant report makes contingent recommendations for decarbonizing linehaul trucking activities in order to contribute to Shipment Zero and other net-zero carbon goals.