Veterans Medical Marijuana Safe Harbor Act This bill allows: (1) a veteran to use, possess, or transport medical marijuana in accordance with applicable state law; (2) a Department of Veterans Affairs (VA) physician to discuss with a veteran the use of medical marijuana as a treatment if the physician is in a state that authorizes such treatment; or (3) a VA physician to recommend, complete forms for, or register veterans for participation in a state-approved medical marijuana treatment program. The VA shall report to Congress regarding: (1) the effects of medical marijuana on veterans in pain; and (2) the relationship between state-approved medical marijuana treatment programs, program access, and opioid abuse reduction.