Indicators of supply, access, and use of healthcare are helpful for characterizing services, planning activities, and organizing demand. This study describes patterns of use of outpatient care and the associations with demographic and socioeconomic factors, morbidity, population size of the municipality and region, and administrative and financial classification of the provider. This was a population-based cross-sectional study with a sample of 12,402 Brazilian adults from 20 to 59 years of age living in urban areas of 100 municipalities from five regions. Prevalence of outpatient care in the three months prior to the interview was 34.6%. The Brazilian Unified National Health System (SUS) accounted for more than half (53.6%) of the cases, health insurance was used by 34% of the sample, and out-of-pocket services 12.4%, regardless of region, population size, and morbidity profile. Patterns of use of health services remain socially determined, resulting from the supply, demographic and socioeconomic characteristics, and health profile of users.