Service utilization estimates for inpatient and ambulatory mental health care from the Epidemiologic Catchment Area Project were compared with similar estimates from other sources, principally the Center for Mental Health Services National Reporting Program. Generally, results showed closer correspondence between estimates of the number of persons who used inpatient care than of similar estimates for ambulatory mental health care. Subtotal estimates for the specialty alcohol/other drug abuse/mental health and health care sectors were more similar than were estimates for individual settings. The specialty sector subtotals showed only a 7% difference in patient counts for inpatient care and 13% for ambulatory care, with an 11% difference in visits for the latter. Generally, a reasonable level of congruence was observed, given pronounced differences in methods, procedures, and instruments. Future directions may be able to close data gaps and improve the quality of the national mental health services database.