The Clean Air Act requires the United States Environmental Protection Agency to review routinely the National Ambient Air Quality Standards, including fine particulate matter (PM2.5). A non-governmental Independent Particulate Matter Review Panel recently concluded that the current PM2.5 standards do not protect public health adequately and recommended revising the daily standard from 35 to 25–30 μg/m3 and the annual standard from 12 to 8–10 μg/m3. To assess the public health implications of adopting the PM2.5 standards proposed by the panel, the health benefits are quantified from their implementation based on both current (observed) and future (simulated) air quality data for California. The findings indicate that strengthening the standards would provide significant public health benefits valued at $42–$149 billion. Additionally, the stronger standards are shown to benefit environmental justice via health savings that are allocated more within environmentally and socioeconomically disadvantaged communities.