People with diabetes who took semaglutide before a single-level lower back fusion surgery were less likely to be readmitted to the hospital within 90 days and spent less on post‑surgery care, while not having more complications than those who didn’t take the drug.

Semaglutide, a glucagon-like protein-1 receptor agonist used in diabetes and obesity management, has demonstrated perioperative benefits in other surgical populations. However, its role in spine surgery remains unclear. This study aims to evaluate whether patients undergoing single-level lumbar fusion demonstrate: (1) fewer medical complications; (2) surgical complications; and (3) healthcare utilization as measured by readmissions and costs. A retrospective cohort study using a national claims database from 2010 to 2021. Patients with diabetes mellitus undergoing single-level lumbar fusion were identified and matched 1:5 using propensity scores based on age, sex, body mass index, smoking status, diabetes-related complications, insulin/metformin use, and Elixhauser Comorbidity Index (semaglutide: <i>N</i> =3452; controls: <i>N</i> =15,486). Outcomes included 90-day medical/surgical complications, readmissions, and costs. Multivariate logistic regression was used to calculate odds ratios, 95% confidence intervals, and <i>P</i> values, with statistical significance set at <i>P</i> &lt; 0.003 after Bonferroni correction. Multivariate logistic regression for binary outcomes; cost comparisons conducted with appropriate statistical adjustments. No significant differences were observed in rates of cerebrovascular accidents, myocardial infarctions, venous thromboembolism, pneumonia, hypoglycemia, or surgical site infections (SSIs) (<i>P</i> &gt; 0.05 for all). Semaglutide users had significantly lower 90-day readmission rates (8.7% vs. 11.4%, <i>P</i> &lt; 0.0001) and reduced 90-day costs-of-care (<i>P</i> &lt; 0.0001). A trend toward fewer SSIs was noted (2.5% vs. 3.2%, <i>P</i> = 0.018), though not statistically significant. Semaglutide use before single-level lumbar fusion is associated with reduced 90-day readmissions and costs without increasing complication risk.