This study examined the role of stigma at two stages of the treatment-seeking process by assessing associations between various types of stigma and perceived need for mental health treatment as well as actual treatment use. We analyzed cross-sectional data from the 2014 and 2016 California Well-Being Survey, a telephone survey with a representative sample of 1954 California residents with probable mental illness. Multivariable logistic regression indicated that perceived need was associated with less negative beliefs about mental illness (odds ratio [OR] = 0.72; 95% confidence interval [CI] = 0.54, 0.95) and greater intentions to conceal a mental illness (OR = 1.47; 95% CI = 1.12-1.92). Among respondents with perceived need, treatment use was associated with greater mental health knowledge/advocacy (OR = 1.63; 95% CI = 1.03-2.56) and less negative treatment attitudes (OR = 0.66; 95% CI = 0.43-1.00). Understanding which aspects of stigma are related to different stages of the help-seeking process is essential to guiding policy and program initiatives aimed at ensuring individuals with mental illness obtain needed mental health services.