Research has long focused on the size of police agencies, giving little attention to the composition of the workforce itself. Literature in fields such as the military, healthcare, organizational psychology, and business, highlights the importance of workforce structures in meeting both organizational and staff needs. Using data from a national survey, the authors examine personnel cohorts (i.e., distribution of junior, midlevel, and senior sworn staff) as an element of workforce structure in the largest, U.S. municipal police organizations. The authors describe the importance of cohort structures for enhancing performance (meeting both organizational and individual needs) and assess variation in cohort structures. The authors discuss the cohorts in light of their effects on personnel management, and highlight the importance of existing cohort structures when considering major personnel decisions such as hiring freezes, furloughs, layoffs, and buyouts. The authors summarize future research that could advance theory and policy regarding workforce structures in police and other criminal justice organizations. Abstract published by arrangement with Sage Journals.