Inclusion Criteria:  Diagnosis of Opioid Use Disorder Receiving OUD treatment with a buprenorphine formulation  Exclusion Criteria:  Previous experience with a mindfulness-based intervention program Pregnancy Any serious medical, mental, or cognitive issue that prevents successful participation in a mindfulness-based group treatment program Prior use of ketamine other than as prescribed by a physician Any of the following medical conditions  Blood Vessel Disease Heart Valve Disease Heart Failure Class 2 or Above Heart Disease Pregnancy/Breastfeeding Arteriovenous Malformation History of Intracranial Bleeding or Stroke History of Seizures Hypoxia defined by current need for supplemental oxygen Liver Disease History of allergic reaction to Ketamine Dementia (moderate-severe) History of Psychotic Disorder, Bipolar Disorder, or Personality Disorder Dissociative Identity Disorder