Introduction: The opioid epidemic is a severe problem in the world, especially in the United States, where prescription opioid overdose accounts for a quarter of drug overdose deaths. Objective: To describe psychiatrists’ prescription of opioid, benzodiazepine, and buprenorphine in the United States. Methods: We conducted a retrospective cross-sectional study of the 2016 Medicare Part D claims data and analyzed psychiatrists’ prescriptions of: 1) opioids; 2) benzodiazepines, whose concurrent prescription with opioids can cause overdose death; 3) buprenorphine, a partial opioid agonist for treating opioid addiction; 4) and naltrexone microsphere, a once-monthly injectable opioid antagonist to prevent relapse to opioid dependence. Prescribers with 11 or more claims were included in the analysis. Results: In Medicare Part D in 2016, there were a total of 1,131,550 prescribers accounting for 1,480,972,766 total prescriptions and 78,145,305 opioid prescriptions, including 25,528 psychiatrists (2.6% of all prescribers) accounting for 44,684,504 total prescriptions (3.0% of all prescriptions) and 131,115 opioid prescriptions (0.2% of all opioid prescriptions). Psychiatrists accounted for 17.3% of benzodiazepine, 16.3% of buprenorphine, and 33.4% of naltrexone microsphere prescriptions. The opioid prescription rate of psychiatrists was much lower than that of all prescribers (0.3 vs 5.3%). The buprenorphine prescription rate of psychiatrists was much higher than that of all prescribers (2.3 vs. 0.1%). There was a substantial geographical variation across the United States. Conclusions: The results show that, proportionally, psychiatrists have lower rates of opioid prescription and higher rates of benzodiazepine and buprenorphine prescription.