Patterns of alcohol use and marijuana use among students at 2- and 4-year institutions.

: The objective of this study was to understand substance use patterns of alcohol, marijuana, and simultaneous alcohol and marijuana (SAM) use among 2- and 4-year college students. : Participants were 526 young adults aged 18-23 ( = 355 4-year students;  = 171 2-year students) recruited from February 2015 to January 2016 who were participating in a larger longitudinal study. Latent class analysis (LCA) was used to identify past-month classes of alcohol, marijuana, and SAM use. : Among both 2- and 4-year students, a four-class solution yielded the best-fitting model, with 2-year classes tending to include greater marijuana use and less alcohol use and 4-year classes tending to include heavy alcohol use. Demographic characteristics were largely similar across classes. Classes of alcohol, marijuana, and SAM use differed by education status. Screening and prevention efforts for 4-year students may need to be tailored for the needs of 2-year students.