BACKGROUND CONTEXT Adjacent-segment disease (ASD) of the cervical spine is a common disabling phenomenon that often requires operative intervention. PURPOSE To evaluate the economic impact of revision operations for cervical ASD after previous cervical spine surgery. STUDY DESIGN/SETTING Single-center retrospective cohort analysis. PATIENT SAMPLE Adults who underwent revision cervical spine surgery for ASD. OUTCOME MEASURES Total and direct costs. METHODS Consecutive adults who underwent revision cervical spine surgery for ASD at a single institution between 2007 and 2013 were retrospectively reviewed. Direct costs (surgical supplies/implants, room/care, pharmacy, services) were identified from medical billing data and calculated for each revision surgery for ASD. Not included in direct cost data were charges, surgeon fees, or revision operations for indications other than ASD (ie, pseudarthrosis). No cost data was obtained for the index operations. Incomplete cost data for revision operations was used as criteria for exclusion. Total costs were calculated from the sum of indirect and direct costs. Costs data were stratified based on the approach of the index and revision operations. RESULTS Eighty-five patients (average age 57±10 years; range 23-80 years) underwent revision surgery for cervical ASD. For all revisions, direct costs summed to $2 million (average $23,702) and total cost summed to $3.2 million (average $37,983). Revisions consisted of 45 anterior operations (anterior cervical discectomy and fusions [ACDF]-34; corpectomy-10, cervical disc replacement-1), 32 posterior operations (posterior cervical fusion [PCF]-14; foraminotomy-14; laminoplasty-4), and 8 circumferential operations. Revisions that entailed a circumferential approach had significantly higher average costs (direct: $57,376 ± 31,258; total: $91,409) than revisions performed via a single approach ([anterior: direct costs - $20,084; total costs - $32,141]; [posterior: direct costs - $20,371; total costs - $32,841]). Of the posterior revisions, foraminotomies had the lowest average costs (direct: $5,389; total: $8,972), while PCF was associated with the greatest average costs (direct: $35,950; total: $57,749). Of the anterior revisions, corpectomies (direct: $30,265; total: $48,419) had significantly greater average costs than ACDFs (direct: $17,514; total: $28,033). CONCLUSIONS Revision operations forASD in the cervical spine are highly heterogeneous and were associated with an average direct cost of $27,702 and an average total cost of $37,983. Over a 6-year period at a single tertiary referral center, operative care for 85 patients with cervical ASD represented a significant economic expense (greater than $2.0 million). FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Adjacent-segment disease (ASD) of the cervical spine is a common disabling phenomenon that often requires operative intervention. To evaluate the economic impact of revision operations for cervical ASD after previous cervical spine surgery. Single-center retrospective cohort analysis. Adults who underwent revision cervical spine surgery for ASD. Total and direct costs. Consecutive adults who underwent revision cervical spine surgery for ASD at a single institution between 2007 and 2013 were retrospectively reviewed. Direct costs (surgical supplies/implants, room/care, pharmacy, services) were identified from medical billing data and calculated for each revision surgery for ASD. Not included in direct cost data were charges, surgeon fees, or revision operations for indications other than ASD (ie, pseudarthrosis). No cost data was obtained for the index operations. Incomplete cost data for revision operations was used as criteria for exclusion. Total costs were calculated from the sum of indirect and direct costs. Costs data were stratified based on the approach of the index and revision operations. Eighty-five patients (average age 57±10 years; range 23-80 years) underwent revision surgery for cervical ASD. For all revisions, direct costs summed to $2 million (average $23,702) and total cost summed to $3.2 million (average $37,983). Revisions consisted of 45 anterior operations (anterior cervical discectomy and fusions [ACDF]-34; corpectomy-10, cervical disc replacement-1), 32 posterior operations (posterior cervical fusion [PCF]-14; foraminotomy-14; laminoplasty-4), and 8 circumferential operations. Revisions that entailed a circumferential approach had significantly higher average costs (direct: $57,376 ± 31,258; total: $91,409) than revisions performed via a single approach ([anterior: direct costs - $20,084; total costs - $32,141]; [posterior: direct costs - $20,371; total costs - $32,841]). Of the posterior revisions, foraminotomies had the lowest average costs (direct: $5,389; total: $8,972), while PCF was associated with the greatest average costs (direct: $35,950; total: $57,749). Of the anterior revisions, corpectomies (direct: $30,265; total: $48,419) had significantly greater average costs than ACDFs (direct: $17,514; total: $28,033). Revision operations forASD in the cervical spine are highly heterogeneous and were associated with an average direct cost of $27,702 and an average total cost of $37,983. Over a 6-year period at a single tertiary referral center, operative care for 85 patients with cervical ASD represented a significant economic expense (greater than $2.0 million).