The assessment examined the effectiveness of Kansas Senate Bill 123 (SB 123) over its first 5 years of implementation and found that while offenders sentenced to SB 123 had lower incarceration and revocation filings at 12 months than those sentenced to standard supervision, by 24 months, the differences in recidivism measures had disappeared. It was also found that SB 123 increased the long-term odds of incarceration and revocation filings for offenders in the program compared to those receiving court services. At the system level, SB 123 resulted in a slight reduction in drug possessors entering prison thus alleviating prison populations and reducing prison costs. The individual-level impacts of SB 123 were evaluated using sentencing and revocation data collected by the Kansas Sentencing Commission, while system-level impacts were evaluated using basic algorithms for modeling prison populations. These findings indicate that SB 123 has more of an impact at the system-level as compared to the individual-level. Successes noted from the implementation of SB 123 were the increased availability of better treatment programs for drug offenders, improved supervision and referral practices, improved revocation practices, and more open communication among criminal justice stakeholders at the State and local levels. Seven recommendations for improving SB 123 are discussed. Figures