This study reviews the impact of a sulfur cap-and-trade program on distributions of sulfur within Massachusetts from 1990 thru 2014. The results indicate that sulfur reductions occurred throughout Massachusetts that were proportional, including a targeted study area within the state that meets the operational definition of a marginalized community. While the target study community disproportionately produced more sulfur emissions than surrounding communities, the reductions through cap-and-trade were consistent throughout the entire state. Other factors, beyond cap-and-trade, are identified as possible reasons why all areas of the state saw proportional reductions. But aside from those additional factors, the results indicate that cap-and-trade resulted in substantial and proportional reductions of sulfur throughout Massachusetts. This result informs more recent studies at the national level in the United States which show cap-and-trade programs have the potential to create disproportional impacts, particularly when looking at sulfur emission distributions.