CPT 45121 Reimbursement & Benchmarks | OpenPayer

Summary & Overview

CPT 45121: Pull-Through Resection with Colorectal Anastomosis

Headline: CPT code 45121 covers combined abdominal and perineal pull-through resection with colorectal anastomosis and intraoperative biopsies

Lead: CPT code 45121 identifies a major colorectal surgical procedure in which the diseased rectum and portions of the colon or ileum are removed via both abdominal and perineal approaches, followed by reconnection of the remaining colon to the anus. The code captures procedures that include multiple biopsies of the diseased colon performed during the same operation.

This code matters nationally because it denotes a complex, inpatient surgical service often associated with significant resource use, postoperative care needs, and clinical risk. Payers commonly involved in coverage and reimbursement decisions for this service include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will find an overview of the clinical context for the procedure, typical site-of-service considerations, and the common payer landscape for this code. The publication also covers billing characteristics such as common modifiers and service-line placement. Where available, benchmarks and policy updates relevant to major colorectal resections are summarized to inform coding and administrative stakeholders about coverage patterns and areas for operational attention.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 45121colorectal surgerypull-through resectionanastomosisinpatient surgerysurgical pathologybiopsy proceduresgeneral surgery

Billing Code Overview

CPT code 45121 describes a surgical procedure in which the provider performs a pull-through resection with an abdominal and perineal approach. The surgeon removes the diseased portion of the rectum and removes part or all of the colon or ileum as required, then connects the remaining colon to the anus. Multiple biopsies of the diseased colon tissue are taken during the same operation.

Service type: Major colorectal resection with anastomosis using combined abdominal and perineal approaches
Typical site of service: Hospital inpatient surgical setting (operating room)

Clinical & Coding Specifications

Clinical Context

A typical patient is a 58-year-old male with long-standing ulcerative colitis who presents with recurrent rectal bleeding, chronic tenesmus, weight loss, and failure of medical management including corticosteroids and biologic therapy. Preoperative evaluation includes colonoscopy with biopsy confirming dysplasia, CT abdomen/pelvis to evaluate extent of disease and rule out metastasis, and preoperative clearance with cardiology and anesthesia. The surgical team plans a total proctocolectomy with ileal pouch-anal anastomosis performed using combined abdominal and perineal approaches. Intraoperatively, the surgeon removes the diseased rectum and affected colon segments, creates an ileal pouch, and connects the remaining bowel to the anus; multiple biopsies of colonic tissue are taken for margin assessment and pathology. Typical perioperative workflow includes informed consent, bowel prep, prophylactic antibiotics, intraoperative specimen handling and pathology requests for frozen sections if indicated, postoperative monitoring in a surgical ward or ICU depending on comorbidity, and coordination of home health or ostomy care if a temporary diverting ileostomy is created. Typical site of service is an inpatient acute care hospital operating suite; ambulatory surgery centers are not appropriate for this extensive combined abdominal and perineal resection.

Coding Specifications

Modifier	Description	When to Use
`00`	Standard procedure code (no modifier)	Used when no specific modifier applies; report the base procedure code without descriptive modifier when unmodified.

Related Codes

CPT-45108-ANORECTAL-TUMOR-EXCISION

CPT 45108: Excision of Anorectal Muscle Tumor

CPT-45119-RESTORATIVE-PROCTOCOLECTOMY-WITH-COLONIC-POUCH

CPT 45119: Restorative Proctocolectomy with Colonic Pouch

CPT-45113-PROCTECTOMY-ILEOANAL-ANASTOMOSIS-ILEAL-POUCH

CPT 45113: Partial Proctectomy with Ileoanal Anastomosis and Ileal Pouch

CPT-45130-PERINEAL-RECTAL-PROLAPSE-EXCISION-REANASTOMOSIS

CPT 45130: Perineal Excision and Reanastomosis for Rectal Procidentia

CPT-45160-TRANSSACRAL-TRANSCOCCYGEAL-EXCISION-RECTAL-TUMOR

CPT 45160: Excision of Rectal Tumor via Transsacral or Transcoccygeal Approach

CPT-45172-TRANSANAL-EXCISION-RECTAL-TUMOR-MUSCULARIS-PROPRIA

CPT 45172: Transanal Excision of Rectal Tumor, Full-Thickness

CPT-45116-POSTERIOR-APPROACH-RECTAL-RESECTION-ANASTOMOSIS

CPT 45116: Posterior Rectal Resection with Colorectal Anastomosis

CPT-45100-ANORECTAL-WALL-BIOPSY-ANAL-APPROACH

CPT 45100: Anal Approach Biopsy of Anorectal Wall

CPT-45171-TRANSANAL-LOCAL-EXCISION-RECTAL-TUMOR

CPT 45171: Transanal Local Excision of Rectal Tumor

CPT-45120-ABDOMINOPERINEAL-RECTAL-RESECTION-COLON-ANASTOMOSIS

CPT 45120: Abdominoperineal Rectal Resection with Colon-Anus Anastomosis

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Taxonomy Code	Specialty	Notes
208000000X	Colon & Rectal Surgery	Most commonly performs proctocolectomy and colorectal reconstructions.
207V00000X	General Surgery	General surgeons with colorectal expertise commonly perform this combined abdominal/perineal procedure.
2086S0122X	Pediatric Surgery	Performs analogous procedures in pediatric patients when indicated.
208800000X	Surgical Oncology	May be involved when resection is for malignancy requiring oncologic margins.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`K51.219`	Ulcerative colitis, unspecified, with moderate to severe disease	Ulcerative colitis with dysplasia or failure of medical therapy is a common indication for total proctocolectomy with ileal pouch-anal anastomosis.
`K50.814`	Crohn disease of large intestine, with intestinal obstruction	Crohn disease with refractory or complicated colonic involvement may necessitate proctocolectomy or extensive colonic resection.
`C19`	Malignant neoplasm of rectosigmoid junction	Malignancy involving the rectum/rectosigmoid may require combined abdominal and perineal resection.
`C20`	Malignant neoplasm of rectum	Rectal cancer is a primary oncologic indication for removal of the rectum and affected colon with appropriate margins.
`K62.5`	Hemorrhage of anus and rectum	Severe, uncontrolled rectal bleeding refractory to endoscopic or medical management can be an indication for surgical resection.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`44140`	Colectomy, partial; with anastomosis	May be performed for segmental colon disease preceding or as an alternative to total proctocolectomy; related when additional colonic resection is required.
`45123`	Proctocolectomy, total, with ileostomy or ileal pouch-anal anastomosis; without mucosectomy	Closely related variant when mucosectomy is not performed; used in similar clinical settings and may be selected depending on surgical technique.
`44120`	Enterectomy, resection of small intestine; single resection and anastomosis	May be performed if small bowel resection is required for ischemia or disease identified intraoperatively.
`76930`	Ultrasound guidance for needle placement (e.g., drain)	May be used pre- or postoperatively for placement of abdominal or pelvic drains or abscess drainage under imaging guidance.
`49905`	Colostomy closure, takedown of colostomy	Performed later in the care continuum if a temporary ostomy was created during the proctocolectomy and later reversed.