Simultaneous alcohol and marijuana (SAM) use - or use of both substances with overlapping effects - is common among emerging adults and is linked to increased risk for problematic substance use outcomes. The current study identified subgroups of emerging adult SAM users based on their typical alcohol and marijuana use patterns and compared groups on key individual characteristics. Latent profile analysis uncovered four profiles of SAM users (n=522): Light Users (LU; 49.0%), Moderate Drinkers with Frequent Marijuana Use (MDFM; 37.9%), Moderate Drinkers with High Peak Levels (MDHP; 5.4%), and Heavy/Frequent Users (HFU; 7.7%). Group differences by demographic characteristics were found, with LU more likely to be college attendees/graduates than MDFM. Additionally, HFU were more likely to be Greek-affiliated than both LU and MDFM. Groups also differed based on other drug use behavior and preferred route of marijuana administration. Findings demonstrate diversity among SAM users based on typical substance use patterns.