On November 2, 2015, the protocol for our upcoming study of smoked marijuana for symptoms of PTSD in 76 U.S. military veterans was submitted for approval to the U.S. Drug Enforcement Administration (DEA). This is the final approval needed for the study before we initiate the study and prepare for participant recruitment. Participants will be U.S. veterans, men or women, aged 18 or older with a diagnosis of PTSD that has not improved after trying either medication or psychotherapy. This study will take place in two locations, one at a private practice office in Phoenix, Ariz., led by Site Principal Investigator (PI) Sue Sisley, M.D., and the other at Johns Hopkins University, led by Site PI Ryan Vandrey, Ph.D. The Institutional Review Board at Johns Hopkins granted conditional approval for the study on September 22, pending final approval by the DEA. This study will be sponsored by MAPS and funded by a $2.1 million grant from the Colorado Department of Public Health and Environment. The Coordinating Investigator for this study is Marcel Bonn-Miller, Ph.D., of the University of Pennsylvania.