Discharges against medical advice (AMA) are associated with higher rates of readmission and often considered a target for quality improvement. Non-prescription opioid use is a known risk factor for AMA discharge, but standards of care exist for managing withdrawal and drug cravings in the inpatient setting. Question This project assessed the reasons why patients with a history of opioid use disorder left the hospital during the calendar year 2021 and whether they had been assessed or treated for opioid use disorder during their stay, had post-discharge follow-up, or experienced an unplanned readmission within 30 days. Method/Analysis Chart abstraction was performed for all patients with a history of non-prescription opioid use who were discharged AMA from UCSF Parnassus in 2021 (n = 50). Demographics and data on discharge diagnoses, assessment and treatment of opioid use disorder, and referral to follow-up care were analyzed through frequency analysis. Chart notes describing reason for discharge were analyzed through thematic analysis. Results Compared with UCSF Parnassus' overall inpatient and emergency department population for the same period, the study population was more likely to be young (median age 43 vs. 53 for hospital overall), unhoused (46.7% vs. 7.7%), male (66.7% vs. 50.2%), and Black (17.8% vs. 11.1%). Only 26% of patients received follow-up care post-discharge and 30% of patients experienced an unplanned readmission to UCSF within 30 days of discharge. Only 26% of patients were assessed for opioid withdrawal during their admission and 70% of patients did not receive medication for treating opioid use disorder while in the hospital. The most common reasons for AMA discharge were anxiety and hospital regulations, followed by withdrawal and outside obligations. Overall, the study population was socially vulnerable and would likely benefit from expanded access to inpatient addiction medicine services and post-discharge follow-up care. Reforming hospital policies to be less punitive and restrictive towards patients who use drugs, along with a standard policy for the prompt identification and treatment of withdrawal, may support more patients in completing their hospital stays.