This report uses data collected by the U.S. Bureau of Labor Statistics, the U.S. Department of Health and Human Services, the Massachusetts Department of Public Health, and the U.S. Census Bureau to evaluate the likely impact of the Massachusetts Act Establishing Earned Paid Sick Time. The study is one of a series of analyses by the Institute for Women’s Policy Research (IWPR) examining the costs and benefits of paid sick days policies. It estimates how much time off Massachusetts workers would use under the proposed policy and the costs to employers for that sick time. It also uses findings from previous peer-reviewed research to estimate how this leave policy would save money, by reducing turnover, cutting down on the spread of disease at work, helping employers avoid paying for low productivity, holding down nursing-home stays, and reducing norovirus outbreaks in nursing homes.