Multiple studies have demonstrated decreased recidivism and increased treatment engagement for individuals with serious mental illness involved in Mental Health Courts (MHC). However, the limited availability of social and fiscal resources requires an analysis of the relationship between a program's effectiveness and its costs. Outcome costs associated with a sample of 105 participants discharged for more than 1 year - and grouped by completion status - were compared to an eligible sample not enrolled (n=45). Transactional costs analysis (TCA) was used to calculate outcomes associated with treatment, arrest, and confinement in the 12-month post-MHC. Total outcome costs for the Successful Group ($16,964) significantly differed from the Unsuccessful ($32,258) and Compare Groups ($39,870). Costs associated with the higher number of arrests for those in the Compare Group created the largest differences. Total cost savings between Successful and Compare (M=$22,906) equated to $916,240 and savings between Unsuccessful and Compare (M=$7612) were $494,708. The total combined cost savings for participants in the 12-month post-MHC period was $1,411,020. While it is important to understand that MHCs and the individuals that they serve vary and these results are for a felony-level court, policy makers and researchers can use these results to guide their decision-making.