CPT code 45805 represents an abdominal surgical repair of a rectovesical fistula with creation of a sigmoid colostomy to divert fecal flow while the repair heals. This procedure addresses a complex pelvic-thoracic communication that can cause infection, urinary contamination, and significant morbidity; proper coding and coverage determination affect access to definitive surgical care and hospital resource use. Key national payers examined include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the code, the expected service setting and procedural intent, and the typical payers involved in coverage determinations. The publication outlines where this code sits in clinical workflows — major abdominal operation under general anesthesia with colostomy creation — and highlights the types of information payers and providers commonly review during authorization and claims adjudication. It also points readers to benchmarks and policy considerations relevant to surgical coding, inpatient versus outpatient site-of-service implications, and documentation elements that support medical necessity. Data not available in the input for specific modifiers, associated taxonomies, ICD-10 diagnoses, and related billing codes is noted where applicable.