BACKGROUND CONTEXT Effective management of common adverse events (AE) immediately after lumbar fusion, ie, uncontrolled pain, nausea and vomiting, and urinary retention, is imperative to facilitate discharge. Persisting, intolerable symptoms prolong hospitalization. Enhanced Recovery After Surgery (ERAS) has shown improved outcomes across a variety of surgical population, results in spine surgery is limited. PURPOSE To compare measurable outcomes before and after ERAS implementation. STUDY DESIGN/SETTING Retrospective study. PATIENT SAMPLE Patients undergoing lumbar fusion. OUTCOME MEASURES Pain scores, opioid consumption, AEs and length of stay (LOS). METHODS A comprehensive Spine ERAS clinical pathway was developed. Associated policies and order sets were established. Printed and electronic education resources were produced. The program was fully implemented after a 3-month trial. With IRB approval, a retrospective review of pre-post ERAS consecutive patients was completed. Pre-ERAS (Non-ERAS) patients received traditional care; ERAS patients were treated with evidence-based care pathways including preoperative optimization; screening and prophylaxis treatment of anemia, infection and postoperative nausea and vomiting (PONV); standardized anesthetic, pre-emptive multi-modal analgesia (MMA) and Tranexamic Acid (TXA) use; interventions to promote metabolic status and return to normal function i.e. early catheter removal, mobilization, and diet resumption. Supplemental opioid was changed from patient-controlled analgesia (PCA) with a short acting opioid ie, hydromorphone, to intraoperative intravenous methadone. The intermittent demand dosing from PCA causes significant fluctuation in serum opioid concentration resulting in either inadequate pain control or over sedation. Methadone was preferred due to its long duration and stable serum concentration. Demographics, surgical details, hospitalization, medications and AEs were compared. All opioids were converted to morphine milligram equivalents (MME). Data was analyzed with analysis of variance, Wilcoxon, chi-square, and/or Spearman correlation tests. RESULTS A total of 146 ERAS and 192 Non-ERAS (n-338) patients were included in this series. Patients during the trial period were excluded. Both groups were similar with regards to age, gender, BMI, ASA score, surgery and baseline opioid use (all p>0.05). Preoperative baseline pain scores were comparable between cohorts (ERAS 4.5 vs Non-ERAS 4.2, p=0.401). Comparing cohorts, significant reductions in pain scores were observed in the post-anesthesia care unit (p=0.004) and 24-48 hours post-operatively (p CONCLUSIONS ERAS implementation in lumbar fusion resulted in significant reduction in pain scores, total opioid consumption, hypotension, urinary retention and LOS. A smaller percentage of patients received transfusion. FDA DEVICE/DRUG STATUS Hydromorphone (Approved for this indication), Methadone HCl (Approved for this indication), Tranexamic Acid (Approved for this indication), Patient-Controlled Analgesia (PCA) Pump (Approved for this indication).