This article examines the use of outpatient mental health services in a sample of low-income women (Mothers' Well-Being Study [MWS]) and compares the findings with a sample of similar-aged women in the general population (National Comorbidity Survey [NCS]). Overall, the prevalence of any 12-month mental health was significantly greater for MWS respondents compared with NCS respondents. Only a quarter of each sample with any had received treatment at an outpatient mental health service in the past year. The authors identify implications for social workers who to improve access and quality of care for women in need of specialty mental health and substance use services. KEY WORDS: low-income women; mental health services; substance abuse; welfare ********** The landmark release of Mental Health: A Report of the Surgeon General called for Americans to seek help if you have a mental health problem or think you have symptoms of a mental disorder (U.S. Department of Health and Human Services, 1999, p. 453). The surgeon general's report facilitated widespread attention to the detrimental effects of mental health problems, identified barriers that many people face in seeking treatment, and compiled evidence supporting the positive effects of appropriate treatment. It indicated that recent population studies, such as the Epidemiologic Catchment Area survey (Regier et al., 1993) and the National Comorbidity Survey (NCS) (Kessler et al., 1994), provided benchmark data on the prevalence of service use among people with psychiatric disorders and substance use problems; such population-based prevalence data offer valuable indicators for comparative purposes. The NCS, funded by the National Institute of Mental Health (NIMH), was the first survey to administer face-to-face structured psychiatric interviews to a nationally representative U.S. sample. The NCS has served as a benchmark for the prevalence of mental health and substance abuse disorders in the United States and has also provided data on the level and type of service use for these disorders. It has allowed researchers examining underrepresented groups to compare their findings regarding psychiatric disorders and service use rates with national norms. For instance, in previous studies of homeless women (Bassuk, Buckner, Perloff, & Bassuk, 1998) and Native Americans (Beals et al., 2005), researchers have compared their findings with the NCS as a way of identifying unique needs and possible inequities in vulnerable populations. The Mothers' Well-Being Study (MWS), also funded by NIMH, replicated the NCS, but with a sample of women who were receiving welfare in 1998. This population was underrepresented in the NCS, and the MWS was an opportunity for researchers, service providers, and policymakers to attain a better understanding of welfare mothers' service needs. The NCS and MWS used similar diagnostic instruments to assess a range of 12-month psychiatric disorders and used the same questions about service use in four service sectors (that is, general medical, specialty mental health and substance abuse services, human services, and self-help). The present study contributes to social workers' understanding of welfare clients' service needs and the extent to which their need for psychiatric and substance abuse services is met. We evaluated outpatient mental health services use in a random sample of low-income women (the MWS) and compared the findings with results of analyses conducted on a sample of similar-aged women in the general population (the NCS). Given prior research and the relatively resource-poor environment of the area from which the MWS women were sampled, we expected that MWS women would have lower rates than NCS women of general medical and specialty service use. Because of their contacts with the welfare system, we expected that MWS respondents would have higher rates than NCS respondents of treatment seeking in the human services and self-help sectors. …