This article compares characteristics and health care utilization patterns of homeless veterans entering substance use disorder (SUD) treatment. Baseline self-report and medical record data were collected from 181 homeless veterans participating in a randomized trial of SUD/housing case management. Veterans, categorized as newly (n = 45), episodically (n = 61), or chronically homeless (n = 75), were compared on clinical characteristics and health care utilization in the year prior to baseline. Between-groups differences were seen in stimulant use, bipolar, and depressive disorders. A significant majority accessed VA emergency department services, and nearly half accessed inpatient services, with more utilization among chronically versus newly homeless. A majority in all groups attended VA primary care (73.5%) and mental health (56.9%) visits, and 26.7% newly, 32.8% episodically, and 56.0% chronically homeless veterans initiated multiple SUD treatment episodes (p =.002). A significant proportion of veterans struggling with homelessness and SUDs appear to remain unstable despite high utilization of VA acute and preventative services.