STUDY DESIGN: Retrospective study. OBJECTIVE: The purpose of this study was to determine whether IBD in patients with degenerative lumbar changes undergoing primary 1-2LF is associated with higher rates of (1) in-hospital length of stay, (2) medical complications, (3) readmissions, and (4) costs of care. SUMMARY OF BACKGROUND DATA: In the United States, the prevalence of inflammatory bowel disease (IBD) has increased concurrently with an aging population with degenerative disk changes. In these patients, primary 1- to 2-lumbar fusion (1-2LF) is a common procedure to resolve serious complications of the spine. Studies comparing these patient demographics to hospital lengths of stay, postoperative complications, readmission rates, and costs of care are limited in the literature. METHODS: The inclusion criteria consisted of patients with IBD who underwent 1-2LF, using a 90-day surveillance period, postoperatively. This 90-day surveillance period was used to measure the length of hospital stay, rates of medical complications, rates of readmissions, and overall costs of care. The IBD cohort was matched against a case-matched cohort group. RESULTS: Patients in the study group had significantly longer in-hospital lengths of stay. In addition, patients in the study group had significantly higher incidence and odds of developing postoperative medical complications within 90 days. Also, study group patients had significantly higher readmission rates. Finally, patients in the study group had significantly higher costs of care than their case-matched cohort. CONCLUSIONS: This study demonstrated that patients with IBD and degenerative lumbar disease are burdened with longer in-hospital lengths of stay, rates of postoperative medical complications, rates of readmission, and costs of care after undergoing primary 1-2LF.