The United States (US) Clean Power Plan established state-specific carbon dioxide (CO2) emissions reduction goals for fossil fuel-fired electricity generating units (EGUs). States may achieve these goals through multiple mechanisms, including measures that can achieve equivalent CO2 reductions such as residential energy efficiency, which will have important co-benefits. Here, we develop state-resolution simulations of the economic, health, and climate benefits of increased residential insulation, considering EGUs and residential combustion. Increasing insulation to International Energy Conservation Code 2012 levels for all single-family homes in the US in 2013 would lead to annual reductions of 80 million tons of CO2 from EGUs, with annual co-benefits including 30 million tons of CO2 from residential combustion and 320 premature deaths associated with criteria pollutant emissions from both EGUs and residential combustion sources. Monetized climate and health co-benefits average $49 per ton of CO2 reduced from EGUs (range across states: $12–$390). State-specific co-benefit estimates can inform development of optimal Clean Power Plan implementation strategies.