Inclusion Criteria:  Meet DSM-5 criteria for OUD; Receiving methadone treatment for 1-3 months Age 21-60 yr; Right handed; Males and non-pregnant/non-lactating females; Cognitively intact (total IQ score >80); Use alcohol and/or marijuana <3 times per week; each "time" should consist of <1 marijuana "joint" equivalent and <3 alcoholic drinks.  Exclusion Criteria:  Acutely under the influence of any substance (except methadone) during session; Past 7-day use of illicit drugs (not including cannabis) other than opioids; Urinalysis positive for cocaine, benzodiazepines, barbiturates, amphetamines, or pregnancy; Medical conditions prohibiting use of rTMS; Lifetime psychotic, bipolar, generalized anxiety, or obsessive compulsive disorder; Major depression or suicidality in the past 5 years Past-year SUD other than OUD or tobacco use disorder; Acute/unstable illness making it unsafe for participation; Any prohibited medications; Chronic head or neck pain; Past-month participation in a research study.