Virginia Opioid Treatment-Emergency Department

Inclusion criteria: 1. Signed the informed consent form (ICF) and have the ability to comply with the requirements and restrictions listed therein. 2. Age: ≥ 18 years at time of executing the ICF. 3. Currently meets DSM-5 criteria for moderate to severe OUD. 4. Is clinically stable (respiratory rate \[RR\] ≥ 12, pulse oximetry \> 95%, Glasgow Coma Scale \[GCS\] score of 15) and suitable for the trial in investigator's or designee's judgement. 5. Agrees not to take any buprenorphine products other than those administered during the current study throughout participation in the study. 6. Negative urine pregnancy test for females. 7. Vital signs (BP, HR, temperature) considered within normal limits or non-clinically significant elevation, as assessed by treating physician. 8. Provide a urine drug screen positive for illicit opioids, excluding methadone. 9. Have a COWS score ≥ 8. 10. Is seeking medication-assisted treatment for OUD. Exclusion Criteria: 1. Current diagnosis, other than OUD, requiring chronic opioid treatment. 2. Active suicidal ideation in opinion of the Investigator or designee. 3. Female subject that is lactating, pregnant or planning to become pregnant during their participation in the study. 4. Uncontrolled intercurrent illness including, but not limited to, psychiatric illness that would limit compliance with study requirements or compromise the ability of the subject to provide written informed consent. 5. Known allergy or hypersensitivity to SUBOXONE or SUBLOCADE. 6. Any condition that, in the opinion of the Investigator would interfere with interpretation of subject safety or study results. 7. Currently receiving methadone, depot naltrexone, or Probuphine for OUD or received those treatments for OUD within 30 days prior to consent. 8. Current or concurrent treatment with an investigational agent. 9. Current or concurrent enrollment in another clinical study, or observational study that includes MAT. 10. Treatment for OUD required by court order. 11. Current or pending incarceration/legal action that could affect participation or compliance in the study. 12. Subjects who are unable, in the opinion of the Investigator, to comply fully with the study requirements. 13. Less than 48-72 hours since last use of long acting opioids (i.e., methadone), by self-report. 14. Current intoxication with benzodiazepines or alcohol. 15. Meet current DSM-5 diagnosis for severe Benzodiazepine or Alcohol Use Disorder or endorse benzodiazepine or alcohol withdrawal symptoms. 16. Current illicit opioid users who endorse regular use of long acting opioids (i.e., methadone). 17. Total bilirubin ≥ 1.5x the upper limit of normal (ULN), alanine aminotransferase (ALT) ≥3xULN, aspartate aminotransferase (AST) ≥ 3xULN, serum creatinine \> 2xULN, international normalized ratio (INR) \>1.5xULN. If these results are unable to be obtained prior to enrolling the subject, the investigator can make an initial determination about eligibility based on LFTs collected in the past 6 months from the subject's medical record. 18. Patients with a history of Long QT Syndrome or an immediate family member with this condition or those taking Class lA antiarrhythmic medications (e.g., quinidine, procainamide, disopyramide) or Class Ill antiarrhythmic medications (e.g., sotalol, amiodarone) or other medications that prolong the QT interval.