BackgroundBright light therapy (BLT) is efficacious for seasonal and non-seasonal depression. However, the current state of BLT use in practice is unknown, impeding efforts to identify and address utilization gaps. This study's objective was to investigate BLT delivery in a nationwide U.S. healthcare system. MethodsThis was a retrospective observational study of electronic medical records from all veterans who received outpatient mood disorder-related care in the Veterans Health Administration (VHA) from October 2008 through September 2020. BLT delivery was measured through the placement of light box consults. ResultsOf the 3,442,826 veterans who received outpatient mood disorder care, only 57,908 (1.68 %) received a light box consult. Consults increased by 548.44 % (99.9 % credible interval: 467.36 %, 638.74 %) over the timeframe and displayed a robust yearly cycle that peaked on either December 21st or December 22nd. Past mental health treatment for a mood disorder was associated with a higher probability of a consult (relative risk = 4.79, 99.9 % CI: 4.21, 5.60). There was low representation related to veteran age, gender, race, and ethnicity. LimitationsNo information on patients who declined light boxes or actual light box use following consult placement. ConclusionsOutpatient BLT delivery for mood disorders in the VHA remains low, despite significant growth over the past decade. It also displays a strong seasonal rhythm that peaks on the winter solstice, suggesting a limited focus on seasonal depression and a suboptimal reactive approach to changing sunlight. Overall, there exists ample opportunity for novel implementation efforts aimed at increasing utilization of BLT.