CPT code 43845 identifies a gastric bypass bariatric surgery that reduces stomach volume and bypasses a significant portion of the small intestine to limit absorption and treat morbid obesity. Nationally, this code represents a high-impact surgical intervention used in the management of severe obesity, with implications for surgical capacity, payer coverage policies, and post‑operative care pathways. Key payers commonly involved in coverage and payment decisions include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will find a concise overview of the clinical intent and typical settings for CPT code 43845, a national framing of payer coverage considerations, and what to expect in benchmarking and policy contexts. The publication covers reimbursement benchmark summaries, common billing and coding considerations, and relevant clinical context for patient selection and perioperative care. It also highlights typical sites of service and the service type for stakeholders involved in surgical program planning, utilization review, and billing compliance. Data not available in the input is noted where specific payer rates, taxonomies, ICD‑10 pairings, and related codes would normally appear.