Objective To examine the prevalence of concurrent Veterans Health Administration (VA) and non-VA prescriptions for opioids and sedative-hypnotic medications among post-9/11 veterans in Oregon. Data sources VA health care and prescription data were probabilistically linked with Oregon Prescription Drug Monitoring Program (PDMP) data. Study design This retrospective cohort study examined concurrent prescriptions among n = 19,959 post-9/11 veterans, by year (2014-2016) and by patient demographic and clinical characteristics. Veterans were included in the cohort for years in which they received VA outpatient care; those receiving hospice or palliative care were excluded. Concurrent prescriptions were defined as ≥1 days of overlap between outpatient prescriptions for opioids and/or sedative-hypnotics (categorized as benzodiazepines vs. non-benzodiazepines). Principal findings Among 5,882 veterans who filled opioid or sedative-hypnotic prescriptions at VA pharmacies, 1,036 (17.6 percent) filled concurrent prescriptions from non-VA pharmacies. Within drug class, 15.1, 8.8, and 4.6 percent received concurrent VA and non-VA opioids, benzodiazepines, and non-benzodiazepines, respectively. Veteran demographics and clinical diagnoses were associated with the likelihood of concurrent prescriptions, as was enrollment in the Veterans Choice Program. Conclusions A considerable proportion of post-9/11 veterans receiving VA care in Oregon filled concurrent prescriptions for opioids and sedative-hypnotics. Fragmentation of care may contribute to prescription drug overdose risk among veterans.