A national clean energy standard, modeled upon existing state-level Renewable Portfolio Standards, has been proposed to decarbonize the U.S. electric grid. Most such state policies include municipal solid waste incineration as a form of “renewable” energy, despite incinerators’ prominent contributions to air pollution, primarily in environmental justice communities. This study finds that incinerators emit more greenhouse gas emissions per unit of electricity produced (1707 g CO2e/kWh) than any other power source (range: 2.4 to 991.1 g CO2e/kWh). They also emit more criteria air pollutants than replacement sources of energy, such as natural gas. Incineration’s inclusion in “renewable” or “clean” energy standards is thus counterproductive, as they also divert more than $40 million in subsidies annually from cleaner energy sources. As the electric grid decarbonizes, these disparities will only grow. With most U.S. incinerators nearing their end of life, policy choices about their eligibility for subsidies may well decide whether they shut down or undertake expensive capital improvements to continue operating. Extending incinerators’ operational lives by 20 years would result in excess emissions of up to 637.7 million tonnes CO2e, 61.9 million tonnes NOx, and 161,200 tonnes SO2. Conversely, a rapid shutdown of existing incinerators would help decarbonize the electric grid and reduce criteria air pollution, particularly in environmental justice communities, which are disproportionately burdened by environmental health hazards.