Two revolutionary developments impacted the United States criminal justice system over the past 30 years that are now primed for an institutional reckoning—the legalization of medical marijuana at the state level and the exponential rise of adult drug treatment courts across the country. The states that have legalized medical marijuana also provide criminal immunity protections for qualifying medical marijuana patients, including those serving probationary sentences. Drug treatment courts are a form of intensive probation offering treatment services for participants plagued by substance use disorders. Most drug treatment courts operate on an abstinence-based model and do not permit the use of medical marijuana. Consequently, challenges by drug court participants to the continued prohibition of medical marijuana are on the horizon. The purpose of this article is to highlight the contours of these knotty issues from a sociolegal perspective. The material for this article stems from a review of existing judicial decisions in addition to qualitative data collected during my case studies of three different adult drug treatment courts.