Miami-Dade County is home to the largest percentage of people with serious mental illnesses (SMI; e.g., schizophrenia, bipolar disorder, major depression) of any urban community in the United States. Roughly 9.1% of the population (more than 210,000 individuals) experience SMI, yet fewer than 13% of these individuals receive care in the public mental health system. As a result, law enforcement and correctional officers have increasingly become the lone responders to people in crisis due to untreated mental illnesses. On any given day, the Miami-Dade County Jail houses approximately 1,200 individuals with SMI. This represents approximately 17% of the total inmate population, and costs taxpayers more than $50 million annually. The County jail now serves as the largest psychiatric facility in the State of Florida. The Eleventh Judicial Circuit Criminal Mental Health Project (CMHP) was established to divert nonviolent misdemeanant defendants with serious mental illnesses (SMI) or co-occurring SMI and substance use disorders, from the criminal justice system into community-based treatment and support services. Since that time the program has expanded to serve defendants that have been arrested for less serious felonies and other charges as determined appropriate. The program operates two components: pre-booking diversion consisting of Crisis Intervention Team (CIT) training for law enforcement officers and post-booking diversion serving individuals booked into the jail and awaiting adjudication. All participants are provided with individualized transition planning including linkages to community-based treatment and support services. The CMHP provides an effective, cost-efficient solution to a community problem and works by eliminating gaps in services, and by forging productive and innovative relationships among all stakeholders who have an interest in the welfare and safety of one of our community’s most vulnerable populations.