To determine the effect of patient immigrant status on physician trainees’ diabetes treatment decisions. Participants were 140 physician trainees (‘providers’). Providers viewed videos and vignettes of virtual patients differing in immigrant status (born in Mexico or U.S.; other characteristics held constant). Analyses were completed at the group and individual levels. Providers were less likely to refer foreign-born (vs. U.S.-born) patients to endocrinology. Individual-level results showed an almost even split between treatment ratings for foreign-born vs. U.S.-born patients for three decisions (take no action, add oral hypoglycemic agent, add/switch to insulin), explaining why group-level differences for these ratings did not emerge (i.e., they were cancelled out). Physician trainees are less likely to refer foreign-born patients to endocrinology. Half of individual-level decisions were influenced by patient immigrant status, but group-level analyses mask these differences. Systematic treatment differences based on non-relevant factors could lead to adverse outcomes for immigrants.