For the New York ISO (NYISO), Brattle experts analyzed the effect a $/ton carbon charge would have on carbon emissions and customer costs. The carbon charge would be administered by NYISO in the dispatch process to all carbon-emitting generators, and all collected carbon charges would be refunded to customers. The carbon charge would supplement existing New York clean energy policies such as the Clean Energy Standard (CES). Our work includes evaluating customer cost impacts, and options for preventing leakage of emissions to other states. We also assess how such an approach supports the state’s objectives and interacts with the Regional Greenhouse Gas Initiative (RGGI) and other existing policy instruments.