The Prison Policy Initiative and ACLU Campaign for Smart Justice’s report, Women’s Mass Incarceration: The Whole Pie 2017, offers a deeper understanding of the fastest-growing segment of the incarcerated population: women. The report provides important perspective on how incarcerated women fit into the nation’s larger incarceration crisis, and critical insights into drivers of women’s incarceration. The publication comes at a critical time, as policymakers and reform advocates across the country seek solutions to reduce the nation’s jail and prison population.