Objective: We sought to determine what demographic and clinical factors are associated with receipt of initial mental health treatment. Study Design and Methods: A total of 1177 patients completed structured clinical interviews (Michigan Screening for Treatment and Research Triage) when they called to authorize mental health benefits. Measures included age, sex, alcohol use, drug use, anxiety, depression, medical history, behavioral health treatment history, psychosocial stressors, functioning, and suicidality. Multivariate analyses determined the association between these variables and a behavioral health claim within 90 days of the interview. Results: Among those completing interviews, 85% attended initial mental health treatment. Factors significantly associated with increased odds of treatment initiation were good self-rated health (odds ratio [OR] = 1.70; 95% confidence interval [CI] = 1.15, 2.50), support of family or friends (OR = 1.71; 95% CI = 1.11, 2.65), previous outpatient mental health visits (OR = 1.56; 95% CI = 1.11, 2.19), and recent alcohol use (OR = 1.41; 95% CI = 1.00, 1.97). Factors associated with decreased odds of treatment initiation were recent period of total disability (OR = 0.62; 95% CI = 0.45, 0.87), any previous suicide attempt (OR = 0.56; 95% CI = 0.36, 0.87), 6 or more physician visits for medical reasons this year (OR = 0.64; 95% CI = 0.44, 0.92), and legal problems (OR = 0.31; 95% CI = 0.16, 0.61). In multivariate analyses, family support, history of medical visits, and recent alcohol use were no longer significant predictors. Conclusions: Most individuals in this insured population who completed an initial telephone assessment had an initial behavioral health claim. However, patients with greater health or social service needs were at higher risk for not obtaining treatment, suggesting the need for greater outreach and attention by providers and insurers.