A Study Comparing Oral Buprenorphine and Injectable Buprenorphine for the Treatment of Opioid Use Disorder

Inclusion Criteria:

* Has used opioids within 30 days prior to consent or within 30 days prior to entry into a supervised setting -- e.g., opioid use within the 30 days prior to recent (\<30 days) incarceration, entry into a detoxification facility, or entry into an inpatient hospital setting
* Have started or are in the process of starting on Medications for Opioid Use Disorder (MOUD) via clinical induction on SL-BUP/NLX
* Meets DSM-5 criteria for moderate to severe opioid use disorder (OUD) based on the Mini-International Neuropsychiatric Interview
* Referred to/seeking treatment for OUD and willing to accept "partial-agonist-based" therapy

Exclusion Criteria:

* For Veterans of childbearing potential (a premenopausal person capable of becoming pregnant), pregnancy, breastfeeding, and/or failure to practice an effective method of birth control
* Failure to reach maintenance dose of 4 milligrams (mg) - 32mg SL-BUP/NLX in 45 days or less
* Taking a form of prescribed maintenance Medications for Opioid Use Disorder (MOUD), e.g., methadone, buprenorphine or XR-NTX) continuously \>45 days prior to randomization
* Has a history of significant adverse effects from buprenorphine and/or naloxone
* Has experienced (within the past 2 weeks) recent suicidal or homicidal ideation that requires acute treatment or hospitalization
* Is unwilling or unable to provide consent
* Meets criteria for current (past month) DSM-5 severe sedative hypnotic use disorder based on the MINI Sedative, Hypnotic, or Anxiolytic Use Disorder (SHUD) module
* Anuria and/or dialysis
* Current moderate to severe COVID-19 symptoms with a risk of intubation or critical illness
* Medical, psychiatric, behavioral, or logistical condition which, in the judgement of the Local Site Investigator (LSI) or Co-Investigator (Co-I), requires a higher level of acute care and/or makes it unlikely the patient can participate in or complete the 52-week active phase of the study
* Is actively participating in an interventional clinical trial for which a waiver of dual-enrollment with CSP #2014 has not been obtained