Adolescent overdoses have been rising over the past decade. Emergency department (ED) visits for both acute overdoses and for adolescents in opioid withdrawal have risen post-COVID. Urine drug screens have poor utility in the ED but are routinely obtained for medical clearance and in the management of patients with substance use disorder. Our primary goal was to measure the sensitivity of the opiate urine drug assay over time in opioid-related presentations to the ED.We reviewed ED presentations at all EDs within our health system that were directly related to opioids from 1/1/2014 to 12/31/2022. For each patient included over the time frame, we identified whether a urine drug screen was obtained and the results from this screen. The urine drug screen available at all sites was an enzyme-multiplied immunoassay with an opiate screen (morphine antibody), but no fentanyl screen. The percent positivity for each drug category on enzyme multiplied immunoassay technique testing was calculated. Chi-squared tests were used to compare positivity rates between years.Opiate positivity declined over the last 9 years. Positivity rates from 2020 to 2022 were 5% ± 2% vs 82% ± 6% from 2014 to 2019 ( P < 0.001) Performance of UDS also declined over time (76% from 2014 to 2019 vs 46% from 2020 to 2022; P < 0.001). UDS was more likely to be performed in patients after a suicide attempt or when presenting after illicit use (66% vs 38%; P = 0.004).Opiate screen positivity decreased the last 9 years and may reflect wider use of fentanyl among this population starting in 2020.