The Parent Monitoring–Youth Form (Chilcoat & Anthony, 1996) is a self-report measure that focuses on the supervision and monitoring provided by parents or other responsible caretakers. Seven questions ask the participant to respond on a 5-point Likert-type scale (1 = all of the time, 5 = never) how often his/her parents are involved, are present, and are aware of his/her behavior or whereabouts. Scores were reverse-coded, summed, and averaged such that higher scores indicate higher (i.e., tighter) monitoring. Mean age at parental monitoring assessment was 16.5 (SD 0.9, range 13.4–18.7). In 53.2% of participants, parental monitoring and SRE-5 were assessed at the same wave. For all other participants, we used the next closest parental monitoring assessment (SRE-5 assessment was contingent on age of alcohol use initiation). This parental monitoring age range corresponds to the SRE-5 age range as well as to the time period during which adolescents typically live at home and attend high school. Reliability (Cronbach’s α) for this sample was 0.76. Items can be found in Supplemental Material.