Crystal's MCW Coder Hub🧬CPT 50815 — Ureterocolic Conduit
Overview
CPT 50815 describes a form of urinary diversion in which one or both ureters are surgically implanted directly into the intact, undivided colon — most commonly the sigmoid colon — so that urine drains internally through the bowel and exits via the rectum or an existing colostomy. This is the procedure historically known as ureterosigmoidostomy, and in its modified forms it may also be referred to as a wet colostomy when performed in conjunction with a colostomy takedown or in the setting of pelvic exenteration.
Understanding CPT 50815 requires placing it in careful contrast with its close neighbors in the urinary diversion family. Unlike 50810 (ureterocolon conduit), 50815 does not involve isolating a separate bowel segment and creating a cutaneous urostomy stoma. There is no intestinal anastomosis because the colon is not divided — the ureters are simply tunneled directly into the wall of the colon that remains in continuity. This fundamental anatomical distinction has significant implications both clinically and from a coding perspective, which is why the descriptor for 50815 notably does not include the phrase “including intestinal anastomosis” that appears in 50810 and 50820.
This distinction is not merely academic. It reflects genuinely different physiologic consequences for the patient: because urine mixes directly with fecal content in a ureterosigmoidostomy, patients are at risk for hyperchloremic metabolic acidosis, recurrent urinary tract infections, and — critically — increased risk of adenocarcinoma at the ureteral implantation site over long-term follow-up. These downstream consequences are why ureterosigmoidostomy has largely been replaced by ileal conduit (50820) and continent diversions (50825) in modern urology, making 50815 a less frequently encountered code today. When you do see it, it tends to appear in complex pelvic exenteration cases or in situations where other forms of diversion are anatomically or physiologically not feasible.
Procedure Description & Anatomy
Walking through the operative steps solidifies what this code actually captures and helps distinguish it from 50810 and 50820.
Step 1 — Patient Positioning & Abdominal Access: The patient is positioned supine or in modified lithotomy depending on concurrent procedures. A midline laparotomy or laparoscopic-assisted approach provides access to the retroperitoneum and sigmoid colon.
Step 2 — Ureteral Mobilization: Both ureters are identified and mobilized from the retroperitoneum, taking care to preserve their blood supply via the adventitial sheath. In most cases, both ureters are brought to the same side of the sigmoid colon to facilitate bilateral implantation.
Step 3 — Sigmoid Colon Preparation: The sigmoid colon is identified and remains in continuity — this is the defining anatomical feature of 50815 versus 50810. No bowel segment is isolated, no bowel is divided, and therefore no intestinal reanastomosis is required or performed.
Step 4 — Ureteral-Colonic Anastomosis: Small seromuscular incisions are made in the taenia coli of the sigmoid, and the ureters are implanted using an anti-reflux tunneling technique (the Leadbetter-Clarke or modified Goodwin technique is traditional). The goal is to create a submucosal tunnel long enough to generate a passive anti-reflux valve mechanism, reducing the risk of ascending infection and chronic renal damage.
Step 5 — No Stoma Creation: Because urine drains into the intact colon and exits via the rectum, no cutaneous urostomy stoma is created. This is a major distinction from 50810 and 50820 for both the patient experience and the coding logic. In the “wet colostomy” variant, urine and stool exit together through a single colostomy.
Step 6 — Drain Placement & Closure: Pelvic or retroperitoneal drains are placed, and the abdomen is closed in standard fashion.
Code Details at a Glance
| Field | Detail |
|---|---|
| CPT Code | 50815 |
| Full Descriptor | Ureterocolic conduit |
| Code Family | Urinary Diversion (50800-50830) |
| Global Period | 090 days (Major Surgery) |
| wRVU | ~20.89 (verify against current MPFS annually) |
| Assistant Payable | Yes |
| Bilateral Indicator | Typically bilateral ureters implanted; modifier -50 does not apply to the conduit creation itself |
| Facility vs. Non-Facility | Facility only (hospital/ASC) |
| Anesthesia | General endotracheal |
Note on wRVU: Work RVU values are subject to annual revision by CMS through the Medicare Physician Fee Schedule (MPFS). The value noted above should be treated as a reference estimate and verified against the current calendar year’s MPFS before use in productivity reporting or contract benchmarking. The wRVU for 50815 is generally lower than 50810 (~26.28) and 50820 (~25-27 range) because it does not include the added complexity of bowel division, conduit harvest, and intestinal reanastomosis.
Assistant Surgeon Payable
Yes, assistant surgeon services are payable for 50815. Although 50815 is technically less complex than 50810 in that it avoids bowel division and reanastomosis, it nonetheless involves deep pelvic dissection, bilateral ureteral mobilization, and precise anti-reflux tunneling anastomoses. These demands routinely justify an assistant surgeon. The assistant reports 50815 with modifier -80 (Assistant Surgeon) or -82 (Assistant Surgeon when a qualified resident is not available) in the appropriate setting.
Includes (Bundled — Do Not Report Separately)
The following are considered integral components of 50815 and are not separately reportable on the same date of service:
- Ureteral mobilization and dissection — Routine retroperitoneal dissection to free the ureters is part of the operative field and is included.
- Anti-reflux tunneling technique — The submucosal tunnel construction and ureteral anastomosis to the colonic wall are included in the procedure.
- Intraoperative ureteral calibration stents — When placed transiently during anastomosis construction, these are considered incidental and not separately billable.
- Routine abdominal closure — Fascial and skin closure is included.
- Cystotomy closure, if performed as part of gaining access during a concurrent procedure, is bundled unless separately documented as a distinct, medically necessary procedure.
It is worth emphasizing what 50815 does not include that makes it distinct from 50810: because no intestinal anastomosis is performed, there is nothing to bundle in that regard. The absence of the “including intestinal anastomosis” language in the descriptor is not an oversight — it accurately reflects the operative anatomy.
Excludes / Separately Reportable Considerations
The following services are generally not bundled with 50815 and may be separately reportable when performed as distinct, additional procedures with documented medical necessity:
- Cystectomy — When 50815 accompanies radical or simple cystectomy, the cystectomy is reported separately. Relevant cystectomy codes include 51570, 51575, 51580, 51585, 51590, 51595, 51596. This combined scenario is common in pelvic exenteration and radical cystectomy cases, and both codes are appropriate.
- 38770 — Pelvic lymphadenectomy (external iliac, hypogastric, obturator nodes): if performed as part of concurrent oncologic resection, this is separately reportable.
- 44145 or 44150 — Colectomy procedures: if a concurrent colonic resection is performed for a separate indication, this may be separately reportable with appropriate modifiers and documentation.
- 45126 — Pelvic exenteration for colorectal malignancy: when 50815 is performed as part of a total or anterior pelvic exenteration, 45126 may be the more comprehensive code capturing the overall procedure. Review NCCI edits carefully in this scenario, as the diversion is often considered part of the exenteration.
- 50830 — Urinary undiversion: if a prior urinary diversion is being taken down and reconstructed in the same session, this may be separately reportable. Document the clinical distinction clearly.
- Long-term ureteral stenting — If a separately placed, long-term indwelling ureteral stent is placed as a distinct clinical service, consider 50605 or 52332 depending on approach.
- 49000 — Exploratory laparotomy: only separately reportable when a planned exploratory procedure is performed as a truly distinct service. Do not reflexively report alongside 50815.
CPT Code Tree — Urinary Diversion Family (50800-50830)
Placing 50815 in its full code family context is essential for accurate code selection, particularly because the distinctions between these codes hinge on relatively subtle clinical and anatomical differences that are easy to miss in operative note review.
50800 — Ureteroenterostomy, direct anastomosis of ureter to intestine: The foundational concept in this family — direct ureteral implantation into bowel without creating a conduit segment and without the specific sigmoid/colon-focused approach described in 50815. Used less frequently as a standalone in modern practice and can overlap conceptually with 50815 in some documentation scenarios. If the operative note describes direct ureteral implantation into an intestinal segment without specifying a conduit structure or a cutaneous stoma, 50800 may be the appropriate selection — query the surgeon if ambiguous.
50810 — Ureterocolon conduit, including intestinal anastomosis: An isolated segment of colon is harvested as a conduit, the bowel is reanastomosed (included), and urine drains via a cutaneous stoma. This is the colon-based equivalent of the Bricker procedure. The presence of bowel division, reanastomosis, and a cutaneous stoma distinguishes it from 50815.
50815 — Ureterocolic conduit: The subject of this note. Ureters implanted into the intact, undivided colon. Urine drains via the rectum or a wet colostomy. No cutaneous urostomy stoma. No bowel division. No intestinal anastomosis.
50820 — Ureteroileal conduit (Bricker procedure), including anastomosis of ileum: The most commonly performed urinary diversion in contemporary urology. Uses an isolated ileal segment as the conduit with a cutaneous stoma. Includes the ileoileal anastomosis restoring bowel continuity. The first choice when intestinal anatomy is favorable and no prior radiation has damaged the ileum.
50825 — Continent diversion, including intestinal anastomosis using any segment of small and/or large intestine: Reserved for continent urinary diversions — Indiana pouch, Koch pouch, Mitrofanoff, or orthotopic neobladder. These require a reservoir with a continence mechanism and are considerably more complex reconstructions. The patient either catheterizes a stoma or voids per urethra; there is no passive, incontinent drainage.
50830 — Urinary undiversion: Used when a previously created diversion (of any type) is surgically reversed or reconstructed into normal or near-normal anatomy.
ICD-10-CM Diagnoses Commonly Associated with 50815
Because 50815 is performed almost exclusively in the context of severe, often malignant pelvic pathology — or in certain congenital and end-stage benign scenarios — the following diagnoses represent the most clinically and coding-relevant pairings. HCC assignments reflect the CMS-HCC Risk Adjustment Model (v24/v28); always verify against the current model year.
Malignant Neoplasms of the Bladder
Invasive bladder cancer remains one of the most common triggers for urinary diversion, including the ureterocolic approach when pelvic anatomy favors it.
C67.0 — Malignant neoplasm of trigone of urinary bladder C67.1 — Malignant neoplasm of dome of urinary bladder C67.2 — Malignant neoplasm of lateral wall of urinary bladder C67.3 — Malignant neoplasm of anterior wall of urinary bladder C67.4 — Malignant neoplasm of posterior wall of urinary bladder C67.5 — Malignant neoplasm of bladder neck C67.6 — Malignant neoplasm of ureteric orifice C67.8 — Malignant neoplasm of overlapping lesion of bladder C67.9 — Malignant neoplasm of bladder, unspecified
HCC Assignment (v24): Bladder malignancies map to HCC 12 (Lung and Other Severe Cancers) under CMS-HCC v24. Under the restructured v28 model, bladder cancers generally map to HCC 17 (Lung and Other Severe Cancers — revised grouping). In both models, these carry significant risk weights reflecting the high resource utilization of invasive bladder cancer management. This HCC capture is critical at every inpatient encounter.
Malignant Neoplasms of the Cervix and Uterus
Pelvic exenteration for recurrent or locally advanced cervical or uterine cancer is one of the more common modern indications for 50815, particularly in the wet colostomy variant.
C53.0 — Malignant neoplasm of endocervix C53.1 — Malignant neoplasm of exocervix C53.8 — Malignant neoplasm of overlapping lesion of cervix uteri C53.9 — Malignant neoplasm of cervix uteri, unspecified C54.1 — Malignant neoplasm of endometrium C55 — Malignant neoplasm of uterus, part unspecified
HCC Assignment (v24): Cervical and uterine malignancies map to HCC 11 (Colorectal, Bladder, Ureter, and Renal Pelvis Cancers) or HCC 12 depending on specific code and model version. Verify current v28 mappings. These diagnoses are high-value for risk adjustment and should be coded to the highest specificity possible.
Malignant Neoplasm of the Rectum and Sigmoid Colon
When pelvic exenteration for rectal or sigmoid cancer includes urinary diversion as part of a total pelvic resection, 50815 may be the diversion of choice — particularly in the wet colostomy configuration.
C19 — Malignant neoplasm of rectosigmoid junction C20 — Malignant neoplasm of rectum C18.7 — Malignant neoplasm of sigmoid colon
HCC Assignment (v24): Colorectal malignancies map to HCC 11 (Colorectal, Bladder, Ureter, and Renal Pelvis Cancers). These are strong HCC captures in the inpatient setting and should not be overlooked as secondary diagnoses when the primary is bladder or gynecologic malignancy.
Malignant Neoplasms of the Ureter and Renal Pelvis
Upper tract urothelial carcinoma with bilateral involvement or with concurrent cystectomy may necessitate urinary diversion.
C66.1 — Malignant neoplasm of right ureter C66.2 — Malignant neoplasm of left ureter C66.9 — Malignant neoplasm of ureter, unspecified C65.1 — Malignant neoplasm of right renal pelvis C65.2 — Malignant neoplasm of left renal pelvis C65.9 — Malignant neoplasm of renal pelvis, unspecified
HCC Assignment (v24): C65.x and C66.x both map to HCC 12 under v24. Important secondary diagnoses when the primary procedure is driven by upper tract disease.
Congenital Anomalies
Ureterosigmoidostomy has a long historical association with congenital bladder exstrophy and cloacal anomalies, where it may be performed in childhood and revised in adulthood.
Q64.10 — Exstrophy of urinary bladder, unspecified Q64.11 — Supravesical fissure of urinary bladder Q64.12 — Cloacal exstrophy of urinary bladder Q64.19 — Other exstrophy of urinary bladder Q64.79 — Other congenital malformations of bladder and urethra
HCC Assignment: Congenital anomaly codes in this family do not carry HCC assignments. They are nonetheless important for complete clinical documentation, particularly in younger patients who have had staged urologic reconstructions.
Radiation-Induced and End-Stage Bladder Disease
When 50815 is selected because the ileum is not usable due to prior radiation damage, radiation cystitis often appears as the indication.
N30.40 — Irradiation cystitis without hematuria N30.41 — Irradiation cystitis with hematuria
HCC Assignment: N30.x codes do not carry HCC assignments, but they are important for MS-DRG optimization because they may qualify as CC or MCC depending on associated complications. Irradiation cystitis with hematuria (N30.41) and associated anemia may generate additional CC weight.
Fistulous and End-Stage Bladder Pathology
N32.1 — Vesicointestinal fistula N32.89 — Other specified disorders of bladder
HCC Assignment: Neither carries HCC assignment. However, complex fistulous disease represents a significant clinical comorbidity that should be documented for DRG complexity capture.
MS-DRG Assignment
The MS-DRG assignment for an encounter where 50815 is the principal operative procedure is primarily driven by the principal diagnosis and the CC/MCC burden of the secondary diagnoses. Because 50815 is an OR-status procedure, it will trigger a surgical DRG.
Primary DRG Family — Other Kidney & Urinary Tract Procedures (when the principal diagnosis is a bladder or urinary tract condition):
| MS-DRG | Description | Approximate Relative Weight |
|---|---|---|
| 673 | Other Kidney & Urinary Tract Procedures with MCC | ~4.5-5.2 |
| 674 | Other Kidney & Urinary Tract Procedures with CC | ~2.8-3.2 |
| 675 | Other Kidney & Urinary Tract Procedures without CC/MCC | ~1.8-2.2 |
When Cystectomy Is Performed Concurrently (the more common clinical scenario), the DRG grouper will evaluate both the cystectomy and the diversion codes and assign based on the highest-weighted OR procedure combined with principal diagnosis. In those cases, the DRG typically shifts to:
| MS-DRG | Description |
|---|---|
| 303 | Kidney, Ureter & Major Bladder Procedures for Neoplasm with MCC |
| 304 | Kidney, Ureter & Major Bladder Procedures for Neoplasm with CC |
| 305 | Kidney, Ureter & Major Bladder Procedures for Neoplasm without CC/MCC |
When Pelvic Exenteration Drives the Encounter (e.g., cervical or rectal cancer with 45126 as the principal procedure), the DRG may shift to a colorectal or gynecologic surgical family depending on the principal diagnosis. In these cases, 50815 is a secondary OR procedure, and the grouper will select the DRG that best reflects the overall surgical complexity. Always run the encounter through your facility’s grouper to confirm, as multi-OR-procedure encounters can produce unexpected DRG logic.
Optimization Tip: The difference between landing in DRG 673 versus 674 versus 675 can represent several thousand dollars in reimbursement. Thorough secondary diagnosis capture — particularly radiation injury, metabolic acidosis, malnutrition, anemia, chronic kidney disease, and any documented infectious complications — can legitimately move the encounter from a no-CC/MCC to a CC or MCC tier. Work with your CDI team to ensure these conditions are queried and documented when clinically present.
Coding Examples
Example 1 — Muscle-Invasive Bladder Cancer, Radical Cystectomy with Ureterocolic Diversion
Clinical Scenario: A 71-year-old male with T3a high-grade urothelial carcinoma of the bladder undergoes radical cystoprostatectomy. Due to prior pelvic radiation for prostate cancer that has compromised the ileum, the urologist elects to perform a ureterocolic conduit rather than an ileal conduit. Both ureters are implanted into the intact sigmoid colon using an anti-reflux tunneling technique. No bowel is divided. The patient also has stage 3 chronic kidney disease and hypoalbuminemia documented in the record.
ICD-10-CM Principal Diagnosis: C67.2 — Malignant neoplasm of lateral wall of urinary bladder (or specify documented wall) Secondary Diagnoses:
- Z85.46 — Personal history of malignant neoplasm of prostate (if prostate cancer is in remission or history)
- N18.3- — Chronic kidney disease, stage 3 (CC — contributes to DRG tier)
- E43 — Unspecified severe protein-calorie malnutrition (MCC — if hypoalbuminemia meets malnutrition criteria with physician documentation)
- N30.40 — Irradiation cystitis without hematuria (documents rationale for colon vs. ileal conduit)
CPT Codes:
- 51590 — Cystectomy, complete, with ureteroileal conduit (review descriptor; some scenarios favor 51595 or 51596 — verify with operative note)
- 50815 — Ureterocolic conduit
- 38770 — Pelvic lymphadenectomy
MS-DRG: 303 (with MCC from E43) vs. 304 (with CC from N18.3- if malnutrition not documented to MCC threshold)
Example 2 — Pelvic Exenteration for Recurrent Cervical Cancer, Wet Colostomy
Clinical Scenario: A 58-year-old female with recurrent cervical carcinoma invading the bladder and rectum undergoes total pelvic exenteration. The urologist creates a wet colostomy in which both ureters are implanted into the sigmoid colon, which is then brought out as a single end colostomy draining both urine and feces. No separate urostomy stoma is created.
ICD-10-CM Principal Diagnosis: C53.8 — Malignant neoplasm of overlapping lesion of cervix uteri Secondary Diagnoses:
- C67.9 — Secondary malignant neoplasm of right kidney and renal pelvis (or C79.19 for other urinary organs if bladder secondarily involved)
- Z87.42 — Personal history of cervical cancer (if applicable for prior treatment)
- E11.65 — Type 2 diabetes with hyperglycemia (if present — potential CC/MCC)
CPT Codes:
- 45126 — Pelvic exenteration for colorectal malignancy, with colostomy and/or ileostomy, with or without bladder excision
- 50815 — Ureterocolic conduit (review NCCI edits; the diversion may be bundled into 45126 depending on payer — append modifier -59 or XU if separately payable and edits allow)
MS-DRG: Will likely fall into colorectal or gynecologic surgical DRG family driven by C53.8 as principal diagnosis. Run through grouper to confirm.
Example 3 — Congenital Bladder Exstrophy, Adult Revision to Ureterocolic Diversion
Clinical Scenario: A 34-year-old male with bladder exstrophy who underwent prior urinary reconstruction in childhood now presents with failed prior diversion. The urologist performs a ureterocolic conduit implanting both ureters into the sigmoid colon as a new form of urinary diversion.
ICD-10-CM Principal Diagnosis: Q64.10 — Exstrophy of urinary bladder, unspecified Secondary Diagnoses:
- N13.30 — hydronephrosis, unspecified (if present from prior failed diversion — potential CC)
- N18.2 — Chronic kidney disease, stage 2 (if documented)
- Z87.39 — Personal history of other endocrine, nutritional, and metabolic diseases (if applicable)
CPT Codes:
- 50815 — Ureterocolic conduit
- 50830 — Urinary undiversion (if the prior failed diversion is being taken down in the same session — separately reportable with documentation of distinct service)
MS-DRG: 673, 674, or 675 depending on CC/MCC burden
Clinical & Coding Pearls
The nuances around 50815 are worth sitting with carefully, because this is a code that can cause real confusion in operative note review — particularly when notes are templated or use legacy terminology.
Distinguish “ureterosigmoidostomy” language carefully. Many older operative notes and some contemporary ones will use the term “ureterosigmoidostomy” interchangeably with ureterocolic conduit. In ICD-10-PCS this distinction matters for the root operation assignment, and in CPT it should consistently map to 50815 when the colon is undivided and urine drains rectally. If the note uses this terminology but describes a cutaneous stoma, query the surgeon — you may be looking at 50810 instead.
The absence of intestinal anastomosis language in 50815 is meaningful, not a gap. New coders sometimes wonder if there is a missing component when comparing 50815 to 50810 and 50820, which both include “intestinal anastomosis” in their descriptors. The answer is that 50815 simply doesn’t involve dividing the bowel, so there is no anastomosis to include. Do not add a bowel anastomosis code to 50815 encounters.
The wet colostomy scenario is the most common modern presentation of 50815. When you see pelvic exenteration operative notes — particularly for gynecologic cancers — look carefully at how the surgeon handles urinary drainage. If both urine and feces exit through a single colostomy, that is the wet colostomy variant captured by 50815, not 50810 or 50820.
HCC capture here is substantial. The malignant diagnoses that most commonly drive 50815 — bladder cancer, cervical cancer, colorectal cancer — all carry significant HCC weight. At the inpatient level, every secondary malignancy, every metastatic site, every complicating comorbidity should be reviewed and coded to the highest specificity. A missed HCC 11 or HCC 12 diagnosis represents real risk adjustment dollars.
NCCI edits in pelvic exenteration cases require careful review. When 50815 is performed alongside 45126, payer-specific NCCI logic may consider the diversion bundled into the exenteration. Always review current NCCI edit tables and append modifier -59 or the appropriate X-modifier (-XU, -XS, -XE, -XP) only when there is a clear, documentable basis for unbundling per CMS guidelines. Never append unbundling modifiers as a routine workaround.
Document the rationale for colon versus ileum. When prior radiation, Crohn’s disease, or prior bowel surgery makes the ileum unusable, that clinical rationale belongs in the operative note and the problem list. It may support medical necessity for the unusual diversion choice, and it produces separately codeable diagnoses (radiation enteritis, Crohn’s, prior bowel resection status) that contribute to CC/MCC tier placement.
Metabolic acidosis is a known complication of ureterosigmoidostomy. If the patient develops hyperchloremic metabolic acidosis postoperatively — a well-recognized and expected complication of urine mixing with fecal content in the colon — this should be documented and coded. E87.2 (Acidosis) carries CC weight and will affect DRG assignment. This is a legitimate, clinically real complication that coders should actively query for in post-operative documentation.
Related CPT Codes (Quick Reference)
| Code | Description |
|---|---|
| 50800 | Ureteroenterostomy, direct anastomosis of ureter to intestine |
| 50810 | Ureterocolon conduit, including intestinal anastomosis (colon segment, cutaneous stoma) |
| 50815 | Ureterocolic conduit — intact colon, rectal or wet colostomy drainage (this note) |
| 50820 | Ureteroileal conduit (Bricker), including anastomosis of ileum |
| 50825 | Continent diversion, including intestinal anastomosis |
| 50830 | Urinary undiversion |
| 45126 | Pelvic exenteration for colorectal malignancy |
| 51590 | Cystectomy, complete, with ureteroileal conduit |
| 51595 | Cystectomy, complete, with continent diversion |
| 51596 | Cystectomy, complete, with continent bladder |
| 38770 | Pelvic lymphadenectomy |
FYI: Tthe wet colostomy distinction is something a lot of general coders miss entirely, so the 50815 versus 50810 comparison in this note is deliberately thorough — it may serve you well as a reference when you’re fielding questions from CDI staff or physicians who aren’t sure which diversion was actually performed.
Also, the metabolic acidosis pearl at the bottom is genuinely worth keeping front of mind for post-op encounters following this procedure. Hyperchloremic acidosis after ureterosigmoidostomy is almost a physiologic inevitability in many patients, and E87.2 at the CC level is a legitimate capture that’s frequently missed because it’s subtle on lab review and rarely makes it into attending documentation without a query.
Last reviewed: 2026-03-11 | Verify wRVU and MS-DRG weights against current-year CMS data