CPT 45112 Rectal Resection Reimbursement | OpenPayer

Summary & Overview

CPT 45112: Rectal Resection with Colonic Anastomosis to Anus

CPT code 45112 represents a combined abdominal and perineal resection of the rectum with colonic anastomosis to the anus, most commonly performed for rectal cancer to preserve normal defecation. Nationally, this code captures a major inpatient colorectal surgery that has implications for hospital resources, surgical quality measures, and payer reimbursement policies. It is relevant to surgical oncology, colorectal surgery programs, and inpatient surgical administrators.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical intent of the procedure, typical care settings, and the reasons the code matters for case mix, utilization, and quality reporting. The publication also summarizes common billing modifiers associated with this service and points to related clinical and coding considerations.

The report provides benchmarks and context for utilization and reimbursement trends where available, summarizes relevant policy updates that affect coverage and prior authorization practices, and outlines clinical context for billing and coding teams. Data not available in the input is noted where appropriate.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare45112CPTcolorectal surgeryrectal resectionabdominoperinealinpatient surgerysurgical oncologyanastomosis

Billing Code Overview

CPT code 45112 describes a surgical procedure in which the provider removes the rectum and anastomoses the colon to the anus using both an abdominal and perineal approach. The procedure is typically performed to treat rectal cancer and is intended to preserve an uninterrupted digestive tract so the patient can pass stool normally.

Service type: Abdominoperineal colorectal resection with restoration of intestinal continuity (combined abdominal and perineal surgical procedure)
Typical site of service: Inpatient surgical setting (operating room with pre- and post-operative inpatient care)

Clinical & Coding Specifications

Clinical Context

A 62-year-old patient with a biopsy-proven mid-rectal adenocarcinoma presents after staging that shows a resectable tumor without distant metastases. The multidisciplinary team recommends an abdominoperineal resection with coloanal anastomosis (procedure 45112) to achieve oncologic resection while preserving bowel continuity. Preoperative workup includes colonoscopy, pelvic MRI, CT chest/abdomen/pelvis, cardiopulmonary clearance, and discussion of bowel preparation and perioperative antibiotics. The operative workflow begins with an abdominal phase to mobilize the left colon and ligate vascular pedicles, followed by a perineal phase to excise the rectum and perform a hand-sewn or stapled coloanal anastomosis. Intraoperative documentation includes indication (rectal cancer), tumor location and extent, margins, estimated blood loss, drains placed, specimen description, intraoperative complications, and disposition. Typical post-operative care includes monitoring in a surgical ward or intensive care setting as appropriate, pain control, DVT prophylaxis, early ambulation, assessment of anastomotic integrity, and coordination for adjuvant oncology if indicated. Typical site of service is an inpatient acute care hospital. Service type is a major surgical procedure (open/invasive abdominal and perineal resection) performed by colorectal or general surgeons with colorectal specialization.

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier; standard reporting

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

CPT-45126-PELVIC-EXENTERATION-FOR-ADVANCED-COLORECTAL-GENITOURINARY-CANCER

CPT 45126: Pelvic Exenteration for Advanced Colorectal and Genitourinary Cancer

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

CPT 45130: Perineal Excision and Reanastomosis for Rectal Procidentia

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

CPT 45171: Transanal Local Excision of Rectal Tumor

CPT-45150-RECTAL-STRICTURE-INCISION

CPT 45150: Incision of Rectal Stricture

CPT-45135-RECTAL-PROCIDENTIA-EXCISION-ABDOMINAL-PERINEAL-ANASTOMOSIS

CPT 45135: Excision of Rectal Procidentia with Abdominal and Perineal Anastomosis

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

CPT 45120: Abdominoperineal Rectal Resection with Colon-Anus Anastomosis

CPT-45110-ABDOMINOPERINEAL-RESECTION-WITH-COLOSTOMY

CPT 45110: Abdominoperineal Resection with Colostomy

CPT-45108-ANORECTAL-TUMOR-EXCISION

CPT 45108: Excision of Anorectal Muscle Tumor

CPT-45114-RECTAL-RESECTION-ANASTOMOSIS-ABDOMINAL-SACRAL-APPROACH

CPT 45114: Rectal Resection and Colon-Rectal Anastomosis, Abdominal and Sacral Approach

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Taxonomy Code	Specialty	Notes
207L00000X	Colon and Rectal Surgery	Colorectal surgeons most commonly perform `45112`.
207N00000X	General Surgery	General surgeons with colorectal expertise perform this procedure in many hospitals.
208000000X	Surgery	Surgical oncologists or abdominal surgeons may perform related resections.
207K00000X	Gastroenterology Surgery (if applicable)	Occasionally involved for perioperative endoscopic management; not primary operator.
2084P0800X	Surgical Oncology	Involvement when cancer-directed surgical expertise is required.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C20`	Malignant neoplasm of rectum	Primary indication for `45112`; rectal adenocarcinoma requiring resection.
`C21.8`	Malignant neoplasm of overlapping sites of anus and rectum	Tumors involving rectum and adjacent anorectal regions that may require combined approaches.
`C19`	Malignant neoplasm of rectosigmoid junction	Tumors at the rectosigmoid may require low rectal resection with coloanal anastomosis depending on location.
`D01.0`	Carcinoma in situ of rectosigmoid junction	High-grade dysplasia or carcinoma in situ that might prompt surgical resection in select cases.
`K62.5`	Anal fissure and fistula (chronic)	Not a primary indication for `45112` but may be documented as comorbidity affecting perineal dissection; included as commonly co-encountered anorectal pathology.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`44145`	Colectomy, partial; total abdominal colectomy with ileorectal anastomosis	May be performed when extended colonic resection is required or for synchronous disease during the same hospitalization.
`44204`	Laparoscopy, surgical; colectomy, partial, with anastomosis	Minimally invasive alternative for colon mobilization in selected cases prior to perineal phase or as combined approach.
`45378`	Colonoscopy, flexible; diagnostic, with or without collection of specimen	Preoperative diagnostic and surveillance colonoscopy to localize tumor and obtain biopsies.
`38531`	Biopsy or excision of lymph nodes (e.g., intra-abdominal)	Lymph node sampling may accompany oncologic resection for staging.
`49020`	Exploration, peritoneal cavity, for tumor resection (laparotomy)	Related to abdominal exploration and tumor debulking that can be part of the operative plan.
`99152`	Moderate sedation services provided by the same physician or other qualified health care professional	May be reported for procedures requiring monitored sedation when billing rules permit (use depends on payer policy).

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