BACKGROUND: In the U.S., overdose deaths and substance treatment admissions related to methamphetamine are rising. This study aims to measure and compare U.S. temporal trends in methamphetamine-involved psychiatric hospitalizations. METHODS: We conducted a population-based, trend analysis of U.S. psychiatric hospitalizations and calculated quarterly (Q) rates per 100,000 population of substance-involved psychiatric hospitalizations. We assessed U.S. regional quarterly percentage hospitalization rate changes using Joinpoint regression. RESULTS: From Q4 2015-Q4 2019, there were 963,202 psychiatric hospitalizations, 50,223 (5.2 %) involved methamphetamine and 102,877 (10.7 %) involved opioids and/or cocaine without methamphetamine. Methamphetamine-involved psychiatric hospitalization rates increased by 68.0 %, psychiatric hospitalizations rates involving opioid and/or cocaine without methamphetamine decreased by 22 %, while nonsubstance-involved psychiatric hospitalizations rates remained unchanged. The largest significant increases in methamphetamine-involved psychiatric hospitalization rates were among people >61 years old, males, and Midwesterners. Methamphetamine-involved psychiatric hospitalization rates doubled among Black patients. The largest average percent increase among methamphetamine-involved psychiatric hospitalizations was 10.2 % from Q4 2015-Q2 2017 in the Midwest. CONCLUSION AND RELEVANCE: Most psychiatric hospitalizations did not involve substances. Methamphetamine-involved psychiatric hospitalizations greatly increased while opioid-involved psychiatric hospitalizations decreased, but involved more total encounters. Greater access to harm reduction services, contingency management programs, and mental health services is urgently needed.