Objectives. To investigate the effects of recreational cannabis laws (RCLs) on the rate of Medicare fee-for-service enrollees with cannabis-related disorders (CRDs) and claims involving CRDs.

Methods. We used Medicare fee-for-service inpatient and outpatient claims from 2010 to 2022 to compare CRD outcomes in US states with and without effective RCLs and open recreational cannabis dispensaries (RCDs) using difference-in-difference models. We estimated the impact of RCLs and RCDs on the overall rate of Medicare enrollees with CRD per 10 000 enrollees and the rate of claims with CRD per 10 000 enrollees at the state‒year level (n = 663).

Results. We found statistically significant increases in CRD outcomes following RCLs (19.73 patients per 10 000 enrollees [P < .001]; 20.56 claims per 10 000 enrollees [P = .005]) and RCDs (14.14 patients per 10 000 enrollees [P < .001]; 13.98 claims per 10 000 enrollees [P = .004]).

Conclusions. Given that RCLs were associated with increased rates of CRD diagnoses and claims including CRD among Medicare fee-for-service enrollees, states considering implementation of RCLs should consider the negative harms of legalization, particularly for older adults. (Am J Public Health. Published online ahead of print April 23, 2026:e1–e4. https://doi.org/10.2105/AJPH.2026.308522)