Inclusion Criteria:  Adult aged 18-64, used heroin in the past 30 days; has a history of heroin use for at least one year; meets the clinical criteria for Opioid Use Disorder (only heroin use will be considered to meet this criteria); meets the clinician clearance using the rTMS Patient Screening Form.  Exclusion Criteria:  do not currently take and medications for a substance use disorder such as methadone, buprenorphine, naltrexone, acamprosate, disulfiram; do not have a psychotic disorder; do not have a diagnosis of another substance use disorder; do not have a history of seizures or other neurological disorders including organic brain disease; epilepsy, stroke, brain lesions, multiple sclerosis, previous neurosurgery; do not have a personal history of head trauma that resulted in a loss of consciousness for more than 5 minutes and retrograde amnesia for more than 30 minutes; do not have a presence of non-fixed metal in body 30 cm to treatment coil. have not taken any medication for a substance use disorder within the last 72 hours before the first rTMS treatment; are not pregnant or think you may be pregnant.