CPT Code for Colon Resection: Right vs Left Colectomy Complete Guide

Colon resection is one of the highest-volume procedures in general surgery, yet selecting the correct CPT code remains a frequent source of billing errors. The difference between a right colectomy, left colectomy, sigmoid resection, and total colectomy involves distinct CPT codes, different wRVU values, and separate considerations for open versus laparoscopic approaches. Getting this wrong means leaving money on the table or triggering an audit.

This guide breaks down every colon resection CPT code you need to know, compares open and laparoscopic values side by side, and walks through the documentation pitfalls that catch even experienced surgeons.

Right Colectomy CPT Codes

Right colectomy (right hemicolectomy) involves resection of the cecum, ascending colon, and hepatic flexure with an ileocolic anastomosis. This is the most common colectomy performed in general surgery, frequently indicated for cecal or ascending colon malignancy, complicated appendicitis, and right-sided diverticular disease.

CPT 44140 is the workhorse code for an open partial colectomy with anastomosis. It covers right, extended right, and transverse colectomies when the bowel is reconnected. This code assumes a single anastomosis is created.

CPT 44204 is the laparoscopic equivalent. Note that the wRVU value is slightly higher than the open approach, reflecting the technical complexity of intracorporeal or extracorporeal laparoscopic anastomosis. If you convert from laparoscopic to open, you report the open code (44140) with modifier 22 if the conversion added significant complexity.

Key documentation point: Specify the extent of resection (cecum through hepatic flexure), the vascular ligation (ileocolic pedicle), and the type of anastomosis (stapled vs hand-sewn, side-to-side vs end-to-end). These details support medical necessity and defend against downcoding.

Left Colectomy CPT Codes

Left colectomy involves resection of the descending colon, often extending from the splenic flexure to the sigmoid-descending junction. The anastomosis is typically between the transverse colon and the sigmoid or upper rectum.

Here is where many coders get confused: a left colectomy with anastomosis uses the same CPT code as a right colectomy (44140 for open, 44204 for laparoscopic). The CPT system does not differentiate between right and left partial colectomy when an anastomosis is performed. The operative note should clearly document the anatomic extent, but the code is identical.

Left Colectomy with Colostomy (Hartmann Procedure)

When a left colectomy is performed without anastomosis -- typically in emergent situations like perforated diverticulitis or obstructing cancer -- the coding changes significantly:

The Hartmann procedure is one of the most commonly miscoded colectomies. If you perform a sigmoid or left colectomy, bring up an end colostomy, and close off the rectal stump, this is 44141 (open) or 44207 (laparoscopic). Do not use 44140 with a separate colostomy creation code -- that will trigger a bundling denial.

Sigmoid Colectomy CPT Codes

Sigmoid colectomy is the most frequently performed colectomy in the United States, driven largely by diverticular disease. The coding depends on whether the procedure includes anastomosis, a colostomy, or formation of a coloproctostomy.

When the sigmoid resection includes a low pelvic anastomosis (connecting the descending colon to the upper rectum below the peritoneal reflection), use 44145 (open) or 44208 (laparoscopic). This distinction matters because a low pelvic anastomosis carries higher technical difficulty and a correspondingly higher wRVU.

Critical distinction: If your anastomosis is above the peritoneal reflection, use 44140/44204. If it is below (coloproctostomy), use 44145/44208. This single anatomic landmark can mean a difference of 3+ wRVUs.

Total and Subtotal Colectomy CPT Codes

Total abdominal colectomy removes the entire colon from the cecum to the rectosigmoid junction. These procedures carry the highest wRVU values in the colectomy family.

For total colectomy with proctectomy and ileal pouch-anal anastomosis (J-pouch), the codes and RVUs increase further:

Complete wRVU Comparison Table

Procedure	Open CPT	Open wRVU	Lap CPT	Lap wRVU
Partial colectomy with anastomosis	44140	23.99	44204	24.42
Partial colectomy with colostomy	44141	24.50	44207	25.18
Partial colectomy, Hartmann type	44143	26.07	44207	25.18
Partial colectomy with coloproctostomy	44145	27.51	44208	27.04
Total colectomy with ileostomy	44150	28.54	44210	30.22
Total colectomy with J-pouch	44158	38.06	44212	39.85

Laparoscopic-to-Open Conversion

When a laparoscopic colectomy is converted to open, report the open CPT code only. Do not report both the laparoscopic and open codes. If the conversion was due to significant unexpected complexity (dense adhesions, uncontrollable bleeding, anatomic distortion), append modifier 22 and include detailed documentation of the circumstances that necessitated conversion and the additional work involved.

Simply converting to open does not automatically justify modifier 22. The conversion must have added substantial additional time, effort, or complexity beyond what a typical open colectomy would entail.

Common Add-On Procedures

Colectomies frequently involve additional procedures that can be billed separately:

• Mobilization of splenic flexure (44139): Add-on code, report only with 44140-44147. Cannot be billed with laparoscopic codes.
• Lysis of adhesions (44005): Only separately reportable if the adhesiolysis is the reason for the surgery or adds substantial time. Incidental adhesiolysis during colectomy is bundled.
• Intraoperative colonic lavage (44701): Separately billable add-on code when performing on-table lavage for unprepared bowel.
• Diverting ileostomy (44310): Can be reported separately with modifier 59 when creating a proximal diversion in addition to the primary colectomy with anastomosis.

Documentation Requirements That Prevent Denials

Audit-proof documentation for any colectomy must include:

1. Indication and medical necessity: Diagnosis (malignancy, diverticulitis, obstruction, volvulus) with supporting clinical data
2. Anatomic extent: Specifically name the segments resected (e.g., "cecum, ascending colon, and hepatic flexure")
3. Vascular ligation: Identify the named vessels divided (ileocolic, right colic, middle colic branches)
4. Anastomosis details: Type (stapled vs hand-sewn), configuration (side-to-side, end-to-end), and location relative to the peritoneal reflection
5. Specimen: Confirmation that a specimen was sent to pathology
6. If laparoscopic: Port placement locations and whether the specimen was extracted through a port site or a separate incision

Pro tip: If your anastomosis crosses below the peritoneal reflection, document that explicitly. The difference between "colorectal anastomosis at the rectosigmoid junction" and "low pelvic coloproctostomy below the peritoneal reflection" can mean 3 extra wRVUs per case.

ICD-10 Codes Commonly Paired with Colectomy

The most frequent diagnosis codes supporting colectomy medical necessity:

• C18.0-C18.9: Malignant neoplasm of colon (by location: C18.0 cecum, C18.2 ascending, C18.6 descending, C18.7 sigmoid)
• K57.20-K57.21: Diverticulitis of large intestine with/without perforation or abscess
• K56.69: Other intestinal obstruction
• K63.1: Perforation of intestine (nontraumatic)
• K56.2: Volvulus (sigmoid volvulus, cecal volvulus)
• D12.0-D12.6: Benign neoplasm of colon (large polyps not amenable to endoscopic removal)
• K51.x: Ulcerative colitis (for total colectomy)

Frequently Asked Questions

Can I bill a right and left colectomy separately in the same session?

No. If you resect both the right and left colon in the same operation, this constitutes a subtotal or total colectomy and should be coded as 44150/44210 (total colectomy), not as two separate partial colectomies.

What if I perform an extended right colectomy that includes the transverse colon?

An extended right colectomy with anastomosis is still reported as 44140 (open) or 44204 (laparoscopic). There is no separate CPT code for "extended" right. If the extent of resection was significantly beyond the typical partial colectomy, consider modifier 22 with supporting documentation.

How do I code a Hartmann reversal?

Hartmann reversal (colostomy takedown with colorectal anastomosis) is reported as 44625 (closure of enterostomy, large or small intestine, with resection and anastomosis other than colorectal) or 44626 (with resection and colorectal anastomosis). The choice depends on whether the anastomosis is above or below the peritoneal reflection.