BACKGROUND: Adult spinal deformity (ASD) is an important problem to consider in the elderly. Although studies have examined the complications of ASD surgery and have compared functional and radiographic results of primary surgery versus revision, no studies have compared the costs of primary procedures with revisions. We assessed the in-hospital costs of these 2 surgery types in patients with ASD. METHODS: The PearlDiver Database, a database of Medicare records, was used in this study. Mutually exclusive groups of patients undergoing primary or revision surgery were identified. Patients in each group were queried for age, sex, and comorbidities. Thirty-day readmission rates, 30-day and 90-day complication rates, and post-operative costs of care were assessed with multivariate analysis. For analyses, significance was set at P < 0.001. RESULTS: The average reimbursement of the primary surgery cohort was $57,078 +/- $30,767. Reimbursement of revision surgery cohort was $52,999 +/- $27,658. The adjusted difference in average costs between the 2 groups is $4773 +/- $1069 (P < 0.001). The 30-day and 90-day adjusted difference in cost of care when sustaining any of the major medical complications in primary surgery versus revision surgery was insignificant. CONCLUSIONS: Patients undergoing primary and revision corrective procedures for ASD have similar readmission rates, lengths of stays, and complication rates. Our data showed a higher cost of primary surgery compared with revision surgery, although costs of sustaining postoperative complications were similar. This finding supports the decision to perform revision procedures in patients with ASD when indicated because neither outcomes nor costs are a hindrance to correction.