OBJECTIVE: U.S. Army personnel experience significant burden from mental disorders, particularly during times of war and with multiple deployments. This study identified the rates and predictors of mental health service use by Army soldiers and examined the association of daily functioning with the various types of mental health service use. METHODS: This study used the U.S. Department of Defense Survey of Health Related Behaviors Among Active Duty Military Personnel, which sampled 10,400 Army soldiers, representing 508,088 soldiers. Mental health service utilization over a 12-month period included receiving counseling or therapy from a general medical doctor, receiving counseling or therapy from a mental health professional, and being prescribed medications for depression, anxiety, or sleep. Current functioning was assessed with the Health-Related Quality of Life-4 instrument. RESULTS: Of the active U.S. Army, 21% had used mental health services in the previous 12 months, and 48% of them had used two or more services. About 7% of soldiers saw a mental health specialist and were prescribed medication. Women (incidence rate ratio [IRR]=1.39, 95% confidence interval [CI]=1.19-1.63) and enlisted soldiers (IRR=1.93, CI=1.49-2.50) were more likely than others to use a greater number of services. Soldiers with higher versus lower levels of impaired functioning were 7.82 times more likely (CI=6.03-10.14) to use mental health services, 4.40 times more likely (CI=3.83-5.05) to use more services, and 3.18 times more likely (CI=1.85-5.49) to see a mental health specialist and to be prescribed medication. CONCLUSIONS: A substantial proportion of the Army accesses mental health services. Soldiers using the highest levels of care had the greatest impairment.