Comorbid alcohol and drug use disorders are treatable and have substantial effects on outcomes and health care utilization in people with schizophrenia. While these substance use disorders (SUDs) are thought to be common in patients with schizophrenia, it has been difficult to characterize prevalence and treatment utilization of this population, since administrative data and medical records may not identify patients with schizophrenia who have an SUD diagnosis. In this study, we used an in-person, population-based survey of 801 individuals with schizophrenia who were in treatment within the Veterans Health Administration (VHA) to inform service delivery for patients with these problems. We examined patient- and clinician-reported data on substance use, psychotic symptoms, medication adherence, and quality of life, plus service utilization records, to understand the extent of comorbid substance use in this population and how those with varying levels of alcohol use utilize services. About 15.3% of the population self-reported use but not misuse of alcohol, while 7.4% reported misuse in the past month. We found few differences in demographic characteristics among those who were alcohol nonusers, users, and misusers, though alcohol misusers reported less frequent medication adherence, more frequent other drug use, worse psychotic symptoms, and worse quality of life. Alcohol users and misusers reported less use of general medical, mental health, occupational, and housing services at VHA, compared with nonusers. Targeted outreach efforts are needed to engage veterans with schizophrenia who drink at any level to engage them in services.