The Behavioral Health Organization (BHO) initiative oversees the transition to managed care for Medicaid recipients who receive mental health (MH) and substance use disorder (SUD) services in New York State. The metrics emphasize improving rates of timely follow-up treatment post discharge, timely filling of appropriate medication prescriptions post discharge, and reducing rates of readmission.The BHO MH Readmissions dataset is designed to assess the frequency with which individuals are admitted for another mental health hospitalization in any region within 30 or 90 days of discharge from a prior mental health inpatient stay, and the frequency with which individuals are admitted for another mental health hospitalization in the same region within 30 days of discharge from a prior mental health inpatient stay. The year 2015 saw the conclusion of the first phase of the Behavioral Health Organization initiative (BHO). A new Behavioral Health Managed Care Transition phase II is underway. The data contained in the BHO metrics span 2010 to 2014, using the 2010 calendar year for a baseline. Earlier in the program (2011‐2012) the metrics were calculated quarterly and on a year‐to‐date basis, later in (2013‐2014), New York State Office of Mental Health opted for semi‐annual and year‐to‐date aggregations.