This year EPA finalized two rulemakings requiring reductions of air pollutants from electric generators (EGUs)the Cross-State Air Pollution Rule (CSAPR) and Mercury and Air Toxics Standards (MATS). Starting in 2012, the CSAPR requires 28 states in the eastern half of the United States to substantially improve air quality by reducing power plant emissions of sulfur dioxide (SO2) and nitrogen oxides (NOX) that cross state lines and contribute to fine particle pollution (PM2.5) and ground-level ozone (O3) in other states. MATS reduces emissions of toxic air pollutants including mercury (Hg), arsenic, chromium, and nickel as well as acid gases including hydrogen chloride (HCl) and hydrogen fluoride (HF) from new and existing coal- and oil-fired power plants across the U.S. starting as early as 2015. As a co-benefit, MATS also reduces SO2 and direct PM2.5 emissions and thereby reduces ambient PM2.5 concentrations. While these rules have separate and distinct goals, cover different geographic areas, and have different implementation timeframes, they are also similar in multiple respects: they affect overlapping sets of electricity producers; they were finalized within six months of each other; they will each substantially reduce exposure to air pollution and thereby improve human health and welfare; and a majority of the quantified benefits of each rule is attributable to reductions in PM2.5 resulting from SO2 emission reductions. Given the similarities between these rules, EPA estimated the national and state-level benefits of these rules combined, which will provide better understanding of their cumulative human health benefits.