Researchers at California State University Channel Islands surveyed nearly 3,000 U.S. adults in 2023, with 996 identifying as medical marijuana users. They found that 43.1% of participants in fully legal states reported using marijuana medically, compared to just 27% in prohibition states. More than 43% of medical marijuana users had not told their primary care provider, with 40% citing fear of disapproval and over 27% citing legal concerns—even in states where medical marijuana was allowed. The findings underscore both the growing acceptance of medical marijuana and the persistent policy and communication gaps that affect how patients use it. Researchers say more work is needed to address costs, patient–provider dialogue, and the clinical implications of marijuana use across diverse populations.