Objective <p>To identify patient and system factors associated with metabolic lab monitoring for patients prescribed second-generation antipsychotics (SGAs) in an outpatient psychiatry setting.</p> Methods <p>This retrospective cohort study used electronic health record data from a large academic psychiatry clinic network (April 2019–April 2024). We included adult patients with at least one visit where a clinician ordered or refilled an SGA. Data included demographics, visit details, and laboratory results. Logistic regression estimated associations with receiving any monitoring, defined as a random glucose, glycosylated hemoglobin, or lipid test. Multiple logistic regression then jointly evaluated patient and clinic characteristics that could affect monitoring.</p> Results <p>Among 2,362 unique patients (14,135 encounters), 42.4% never received monitoring. People of older age, English as a preferred language, Black or African American Race, a Latine ethnicity, and any telehealth utilization were more likely to receive monitoring.</p> Conclusions <p>In addition to confirming persistently low rates of SGA monitoring, this study is novel in identifying specific patient and system factors that influence with whether monitoring occurs. These findings provide insights into why previous improvement efforts may not have achieved widespread success and highlight the need for targeted interventions. Future efforts should address structural barriers to lab completion, including developing workflows for facilitating in-person laboratory measurement during existing appointments and developing EHR optimizations to support lab ordering for patients at greatest risk for not receiving monitoring.</p>