Crystal's MCW Coder Hub🩺 CPT 50820 — Ureterosigmoidostomy
Code Descriptor
50820 — Ureterosigmoidostomy, with or without cystectomy
This CPT code describes the open surgical implantation of one or both ureters directly into the sigmoid colon as a form of permanent urinary diversion, allowing urine to drain through the large intestine and exit via the rectum. This eliminates the need for an external urostomy appliance. The procedure may be performed with or without a concomitant cystectomy (removal of the bladder), depending on the underlying indication. Ureterosigmoidostomy is one of the oldest forms of urinary diversion, largely supplanted in modern urology by ileal conduit diversion (50820 alternative approaches) and continent diversions, but still performed in select cases, particularly in pediatric patients with bladder exstrophy or when bowel length precludes ileal conduit construction. The operation requires meticulous ureteral reimplantation into the sigmoid colon wall using an antireflux submucosal tunneling technique (Leadbetter-Clarke or similar) to prevent ascending urinary infection.
Companion / Related Diversion Codes
| CPT | Description |
|---|---|
| 50800 | Ureterointestinal anastomosis, direct (without sigmoid reservoir) |
| 50810 | Ureterosigmoidostomy with creation of sigmoid bladder and establishment of abdominal or perineal colostomy |
| 50815 | Ureterocolon conduit, including intestine anastomosis |
| 50825 | Continent diversion, including intestine anastomosis using any segment of small and/or large intestine (e.g., Indiana pouch, Kock pouch) |
| 50830 | Urinary undiversion (reconstruction/takedown of prior urinary diversion) |
| 50840 | Replacement of all or part of ureter by intestine segment, including intestine anastomosis |
| 51570 | Cystectomy, complete; without urinary diversion |
| 51580 | Cystectomy, complete; with ureterosigmoidostomy or ureteroproctostomy |
| 51590 | Cystectomy, complete; with ureteroileal conduit or sigmoid bladder, including intestine anastomosis |
| 51595 | Cystectomy, complete; with continent diversion, any open technique |
| 51596 | Cystectomy, complete; with continent bladder substitution |
Caution
⚠️ Critical Bundling Note: When a complete cystectomy is performed at the same operative session as ureterosigmoidostomy, report 51580 rather than separately reporting 50820 + 51570. 51580 is the comprehensive code that includes both the cystectomy and the urinary diversion. Do not unbundle these components.
Anatomy & Clinical Context
Surgical Anatomy
The ureters are retroperitoneal muscular tubes (25-30 cm in length) that transport urine via peristalsis from the renal pelvis to the bladder. They descend along the psoas muscle, cross anterior to the iliac vessels at the pelvic brim, and enter the posterior-inferior bladder wall at the trigone via a valvular, antireflux oblique intramural tunnel.
The sigmoid colon is the S-shaped terminal portion of the descending colon located in the left iliac fossa, continuous with the rectum at the rectosigmoid junction. Its lumen is accessible for ureteral implantation, and the colonic wall musculature can be used to create a submucosal tunnel that mimics the natural antireflux mechanism of the ureterovesical junction.
Mechanism of Continence
In ureterosigmoidostomy, the patient’s anal sphincter serves as the continence mechanism. Urine mixes with stool in the rectosigmoid reservoir, and the patient voids both together. Adequate sphincter tone is an absolute prerequisite; preoperative sphincter assessment (e.g., retention enema testing) is mandatory. Patients who cannot maintain continence with a retention enema are poor candidates.
Historical and Modern Context
Ureterosigmoidostomy was the dominant form of urinary diversion through the mid-20th century. Its use declined sharply after the widespread adoption of the ileal conduit (Bricker procedure) in the 1950s, due to severe long-term complications associated with ureterosigmoidostomy, including:
- Hyperchloremic hypokalemic metabolic acidosis (colonic reabsorption of urinary chloride and ammonia)
- Recurrent ascending urinary tract infections and pyelonephritis (fecal-urinary reflux)
- Renal deterioration from chronic infection and reflux
- adenocarcinoma of the colon at the ureterocolic anastomosis site (10-14% lifetime risk, due to carcinogenic interaction between feces and urine at the mucosal junction — typically manifesting 20-25 years post-diversion)
- Ureteral obstruction at the implantation site
Despite these risks, ureterosigmoidostomy retains a role in:
- Bladder exstrophy in pediatric patients where bowel length is insufficient for ileal conduit
- Developing nations or resource-limited settings where stoma appliances are unavailable
- Selected patients who refuse external stoma and have excellent sphincter function
- Palliative settings where simplicity of reconstruction is prioritized
Operative Technique (Open Ureterosigmoidostomy)
- Patient positioning: Supine; modified Trendelenburg may be used for pelvic access.
- Incision: Lower midline laparotomy (or Pfannenstiel for select cases).
- Ureteral mobilization: Both ureters are identified at the pelvic brim, mobilized proximally with preservation of periureteral adventitia (to protect blood supply), and divided at the ureterovesical junction or distal ureter.
- Sigmoid preparation: The sigmoid colon is mobilized and a suitable antimesenteric segment is selected for ureteral implantation, avoiding tension on the colonic mesentery.
- Antireflux tunnel creation: Using the Leadbetter-Clarke technique (or Goodwin-Hohenfellner), a submucosal tunnel of 3-4 cm length is created in the sigmoid wall. The ureter is drawn through the seromuscular tunnel and spatulated distally before mucosal anastomosis.
- Ureteral anastomosis: The ureter is sutured to the colonic mucosa using fine absorbable suture with a widely spatulated anastomosis to prevent stricture.
- Stenting: Ureteral stents are typically left across each anastomosis for 10-14 days.
- Cystectomy (if included): Performed before or after diversion depending on surgeon preference; see 51580.
- Wound closure: Standard layered closure; drain placement at the discretion of the surgeon.
wRVU & Reimbursement
| Component | Value |
|---|---|
| wRVU | 20.32 |
| Work RVU (CMS) | 20.32 |
| Assistant Surgeon | ✅ Yes — payable |
| Co-Surgery | ✅ Permitted |
| Team Surgery | ✅ Permitted |
| Bilateral Surgery | ❌ Not applicable (bilateral ureters are included in the single code) |
| Global Period | 90 days |
| Facility Only | ✅ Yes — typically performed in hospital setting |
The 90-day global surgical period encompasses all routine pre- and post-operative evaluation and management. Separate E/M services during this period require modifier 24 (unrelated E/M during global period) or 25 (significant, separately identifiable E/M on the day of procedure). Complications managed in the OR during the global period are reported with modifier -78.
⚠️ Bilateral Ureters: Ureterosigmoidostomy inherently encompasses reimplantation of both ureters into the sigmoid colon; this is not a bilateral modifier situation. Report 50820 once. Do not append modifier -50.
Modifiers Commonly Used
| Modifier | Indication |
|---|---|
| -22 | Increased procedural services — prior abdominal surgery, dense adhesions, radiation fibrosis, hostile pelvis, obesity |
| -51 | Multiple procedures — when additional distinct procedures performed same session (applied to the secondary procedure, not 50820) |
| -52 | Reduced services — procedure partially completed |
| -53 | Discontinued procedure — after anesthesia induction but before completion |
| -62 | Two surgeons — co-surgery with another qualified surgeon (e.g., colorectal surgeon managing the colonic component) |
| -66 | Surgical team — complex cases requiring multiple surgeons simultaneously |
| -78 | Return to OR during global period for complication |
| -79 | Unrelated procedure during global period |
| -80 | Assistant surgeon — payable |
| -AS | PA/NP/CRNA assistant at surgery |
Modifier -62 Note: Ureterosigmoidostomy is a procedure that may warrant a co-surgery arrangement when a urologist (managing the ureteral dissection and reimplantation) and a colorectal surgeon (managing the sigmoid colon mobilization and anastomosis) operate simultaneously. Both surgeons report 50820--62, and each receives approximately 62.5% of the allowable.
Common ICD-10-CM Diagnosis Codes
C67.9 — Malignant Neoplasm of Bladder, Unspecified
Description: Bladder cancer, unspecified site within the bladder. This is the most common primary indication for radical cystectomy with urinary diversion in adults. Uroterosigmoidostomy is one of several diversion options at the time of radical cystectomy for muscle-invasive bladder carcinoma (MIBC, T2 and above), high-grade T1 refractory disease, or carcinoma in situ unresponsive to intravesical therapy.
- HCC: ✅ HCC 11 — Colorectal, Bladder, and Other Urinary Tract Cancers (CMS-HCC V24)
- RAF Score Contribution: Significant — bladder cancer is a high-severity HCC diagnosis that substantially increases risk-adjusted payment
- HCC V28: Maps to HCC 17 (Kidney, Bladder, and Other Urinary Tract Cancers) in the updated V28 model
- POA (Present on Admission): Required for inpatient reporting
- MCC/CC Status: ✅ MCC — malignant neoplasm diagnoses carry MCC weight in MS-DRG grouping
- Clinical Note: Always code to the highest specificity — document tumor location within the bladder to assign the most specific subcode
Bladder Cancer Specificity Subcodes:
| Code | Site |
|---|---|
| C67.0 | Trigone of bladder |
| C67.1 | Dome of bladder |
| C67.2 | Lateral wall of bladder |
| C67.3 | Anterior wall of bladder |
| C67.4 | Posterior wall of bladder |
| C67.5 | Bladder neck |
| C67.6 | Ureteric orifice |
| C67.7 | Urachus |
| C67.8 | Overlapping lesion of bladder |
| C67.9 | Bladder, unspecified |
Includes: Transitional cell carcinoma (urothelial carcinoma), squamous cell carcinoma of bladder, adenocarcinoma of bladder, small cell carcinoma of bladder
Excludes 1: Malignant neoplasm of renal pelvis (C65.x), ureter (C66.x), urethra (C68.0)
Q64.10 — Exstrophy of Urinary Bladder, Unspecified
Description: A congenital malformation characterized by eversion of the posterior bladder wall through the absent anterior abdominal wall, exposing the bladder mucosa. Associated with epispadias, pubic diastasis, inguinal hernias, and anomalies of the genitalia. Bladder exstrophy is one of the primary pediatric indications for ureterosigmoidostomy when primary bladder reconstruction fails or is not feasible.
- **G35.-❌ Not an HCC-mapped diagnosis
- POA: Required
- MCC/CC Status: ✅ CC
- Clinical Note: Distinguish between classic exstrophy (Q64.10) and epispadias (Q64.0), which is part of the exstrophy-epispadias complex but coded separately
| Code | Description |
|---|---|
| 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 |
N31.9 — Neuromuscular Dysfunction of Bladder, Unspecified
Description: Impaired neurological control of bladder function, encompassing neurogenic bladder due to spinal cord injury, multiple sclerosis, myelomeningocele, spina bifida, diabetes mellitus, or other neurological conditions. When conservative management (CIC, anticholinergics, intravesical botulinum toxin) fails and the bladder is non-functional with dangerous upper urinary tract deterioration, urinary diversion may be indicated.
- HCC: ❌ Not an HCC-mapped diagnosis
- POA: Required
- MCC/CC Status: Neither MCC nor CC
- Clinical Note: Code the underlying cause of neurogenic bladder as an additional diagnosis (e.g., G82.21 for spinal cord injury, G35.- for MS, Q05.x for spina bifida) for complete clinical capture
| Code | Description |
|---|---|
| N31.0 | Uninhibited neuropathic bladder |
| N31.1 | Reflex neuropathic bladder |
| N31.2 | Flaccid neuropathic bladder |
| N31.8 | Other neuromuscular dysfunction of bladder |
| N31.9 | Neuromuscular dysfunction of bladder, unspecified |
N30.10 — Interstitial Cystitis (Chronic), Without Hematuria
Description: A chronic bladder condition characterized by bladder pain, urgency, frequency, and pelvic discomfort in the absence of infection. In the most severe, refractory cases with contracted, fibrotic bladders (Hunner lesion type), urinary diversion — including ureterosigmoidostomy — may be a last resort after all conservative and surgical treatments have been exhausted.
- HCC: ❌ Not an HCC-mapped diagnosis
- POA: Required
- MCC/CC Status: Neither
| Code | Description |
|---|---|
| N30.10 | Interstitial cystitis (chronic), without hematuria |
| N30.11 | Interstitial cystitis (chronic), with hematuria |
N13.30 — Unspecified Hydronephrosis
Description: Dilation of the renal collecting system due to obstruction of urinary outflow. May be a secondary diagnosis reflecting pre-existing upper tract obstruction necessitating diversion, or a postoperative complication of the ureteral anastomosis (stricture at the ureterocolic anastomosis). When hydronephrosis is the result of ureteral obstruction, specify with N13.1 (with ureteral stricture) or N13.2 (with renal and ureteral calculi).
- HCC: ❌ Not an HCC-mapped diagnosis
- POA: Required — if present postoperatively, this may represent a complication
- MCC/CC Status: ✅ CC (N13.30)
N18.3—N18.6 — Chronic Kidney Disease (CKD), Stages 3-5
Description: CKD is frequently a comorbid condition or long-term consequence of obstructive uropathy, recurrent pyelonephritis, or the primary disease process requiring urinary diversion. Metabolic acidosis from ureterosigmoidostomy (colonic reabsorption of urinary solutes) can accelerate CKD progression.
- HCC: ✅ HCC 137 — Chronic Kidney Disease, Stage 5 (N18.5)
- HCC: ✅ HCC 138 — Chronic Kidney Disease, Severe (Stage 4, N18.4)
- HCC: ❌ CKD Stage 3 (N18.3-) — not HCC-mapped but important as a CC
- MCC/CC Status:
| Code | Description | HCC | MCC/CC |
|---|---|---|---|
| N18.3- | CKD, Stage 3 (moderate) | ❌ | Neither |
| N18.31 | CKD, Stage 3a | ❌ | Neither |
| N18.32 | CKD, Stage 3b | ❌ | Neither |
| N18.4 | CKD, Stage 4 (severe) | ✅ HCC 138 | CC |
| N18.5 | CKD, Stage 5 | ✅ HCC 137 | CC |
| N18.6 | End stage renal disease | ✅ HCC 136 | MCC |
E87.2 — Acidosis
Description: A known and significant metabolic complication of ureterosigmoidostomy is hyperchloremic, hypokalemic metabolic acidosis resulting from colonic reabsorption of urinary chloride (in exchange for bicarbonate) and ammonium. Code E87.2 captures metabolic acidosis as a secondary diagnosis when documented postoperatively or as an ongoing complication.
- HCC: ❌ Not HCC-mapped
- MCC/CC Status: ✅ MCC
- Clinical Note: This is a highly valuable comorbidity capture — metabolic acidosis elevates MS-DRG to the MCC tier, which may shift grouping from DRG 675 to 673
T83.598A — Infection and Inflammatory Reaction Due to Other Prosthetic Device, Implant and Graft in Urinary System — Initial Encounter
Description: Used when a postoperative infectious complication occurs at the ureteral anastomosis site or related to indwelling ureteral stents.
- HCC: ❌ Not HCC-mapped
- MCC/CC Status: Depends on organism code assigned concurrently
⚠️ Complication Coding: When documenting postoperative complications related to ureterosigmoidostomy, the appropriate complication of care code (T83.x category) takes precedence over the symptom code. Always assign an additional code for the associated infection organism (e.g., B96.20 for E. coli) when documented.
Z90.6 — Acquired Absence of Other Parts of Urinary Tract
Description: Status code indicating the patient has undergone cystectomy. Used as a secondary/additional diagnosis in follow-up encounters after radical cystectomy with ureterosigmoidostomy to indicate the absent bladder.
- HCC: ❌ Not HCC-mapped
- POA: N/A (status code)
MS-DRG Assignment
For inpatient hospital admissions, MS-DRG assignment is driven by ICD-10-PCS procedure codes and ICD-10-CM diagnoses. The CPT code 50820 maps to the following ICD-10-PCS procedures for inpatient reporting.
ICD-10-PCS Equivalent Procedures:
| PCS Code | Description |
|---|---|
| 0T160ZA | Bypass Left Ureter to Sigmoid Colon, Open Approach |
| 0T170ZA | Bypass Right Ureter to Sigmoid Colon, Open Approach |
| 0T1B0ZA | Bypass Bilateral Ureters to Sigmoid Colon, Open Approach |
The root operation is Bypass (1) — altering the route of passage of the contents of a tubular body part. The body part character specifies which ureter(s), the approach is Open (0), and the qualifier is Sigmoid Colon (A).
Likely MS-DRG Groupings:
When the principal procedure is ureteral bypass (urinary diversion) and the principal diagnosis is bladder cancer or a major urologic condition, the case typically groups to MDC 11 (Diseases and Disorders of the Kidney and Urinary Tract):
| MS-DRG | Description | GMLOS |
|---|---|---|
| 673 | Other Kidney and Urinary Tract Procedures with MCC | 9.4 |
| 674 | Other Kidney and Urinary Tract Procedures with CC | 5.7 |
| 675 | Other Kidney and Urinary Tract Procedures without CC/MCC | 3.4 |
When radical cystectomy (51580 equivalent, ICD-10-PCS root operation Resection) is the principal procedure, the DRG may group instead to:
| MS-DRG | Description | GMLOS |
|---|---|---|
| 670 | Transurethral Procedures with MCC | 6.3 |
| 671 | Transurethral Procedures with CC | 3.9 |
| 672 | Transurethral Procedures without CC/MCC | 2.4 |
⚠️ DRG Optimization Tip: Capture all comorbidities meticulously. The presence of metabolic acidosis (E87.2, MCC), ESRD (N18.6, MCC), aspiration pneumonia (J69.0, CC), protein-calorie malnutrition (E43, MCC), or sepsis (A41.x, MCC) can shift grouping from DRG 675 → 674 → 673, with significant reimbursement impact. Physician query is essential when these conditions are clinically present but under documented.
Code Tree — CPT Urinary System: Ureter Diversion and Reconstruction (50800-50840)
Urinary System — Ureter └── Introduction / Revision / Reconstruction └── Urinary Diversion ├── 50800 — Ureterointestinal anastomosis (direct, any intestinal segment) ├── 50810 — Ureterosigmoidostomy with sigmoid bladder and colostomy ├── 50815 — Ureterocolon conduit, with intestine anastomosis ├── 50820 ◄◄ Ureterosigmoidostomy, with or without cystectomy ├── 50825 — Continent diversion (Indiana/Kock pouch), with intestine anastomosis ├── 50830 — Urinary undiversion (reconstruction of prior diversion) └── 50840 — Replacement of ureter by intestine segment, with intestine anastomosis Cystectomy with Built-In Diversion (Bundled Codes — Do Not Separately Unbundle) ├── 51570 — Cystectomy, complete; without urinary diversion ├── 51575 — Cystectomy, complete; with bilateral pelvic lymphadenectomy ├── 51580 — Cystectomy, complete; with ureterosigmoidostomy or ureteroproctostomy ├── 51585 — Cystectomy, complete; with ureterosigmoidostomy + bilateral lymphadenectomy ├── 51590 — Cystectomy, complete; with ureteroileal conduit or sigmoid bladder ├── 51595 — Cystectomy, complete; with continent diversion, any open technique └── 51596 — Cystectomy, complete; with continent bladder substitution
Includes
- Open surgical implantation of one or both ureters into the sigmoid colon via submucosal antireflux tunnel technique
- Ureteral mobilization with preservation of periureteral blood supply
- Colotomy and creation of submucosal tunnel (Leadbetter-Clarke, Goodwin-Hohenfellner, or equivalent technique)
- Spatulated ureteral-to-colonic mucosal anastomosis
- Intraoperative ureteral stent placement across the anastomosis
- Concomitant cystectomy when performed (note: if radical cystectomy is performed, consider 51580 as the comprehensive code instead)
- Omental wrap or interposition if performed to reinforce the anastomosis
- Routine drain placement and wound closure
- Intraoperative cystoscopy or ureteroscopy to guide dissection (do not separately report if used solely for guidance)
Excludes / Do Not Report Separately
- 51580 — When complete cystectomy is the primary procedure and ureterosigmoidostomy is the form of diversion, 51580 is the comprehensive code; do not report 50820 + 51570 separately
- 50810 — When a sigmoid bladder reservoir is created with colostomy (a distinct, more complex reconstruction)
- 50825 — For continent urinary diversion using a bowel reservoir (Indiana, Kock, or Mainz pouch); these are a fundamentally different reconstruction
- 50830 — For takedown/revision of a prior urinary diversion
- Bilateral modifier 50 — Do not append; both ureters are included within the single code descriptor
- Intestinal anastomosis repair — Any bowel anastomosis necessary for sigmoid mobilization is included; do not separately report bowel anastomosis
- Ureteral stent placement — Included when performed at the time of ureterosigmoidostomy; do not separately report 50947 or 50688
- Pelvic lymph node dissection — If performed, report separately: 38770 (pelvic lymphadenectomy) or use the bundled cystectomy codes that include lymphadenectomy (51575, 51585)
- Laparoscopic approach — 50820 is an open procedure only; robotic/laparoscopic urinary diversion procedures would require appropriate unlisted codes or confirmed laparoscopic CPT codes
NCCI (National Correct Coding Initiative) Considerations
- 50600 (Ureterotomy) — Bundled with 50820; do not report separately
- 50688 (Change of ureterostomy tube or externally accessible ureteral stent) — Do not report for intraoperative stent placement at the time of reconstruction
- 44140 (Colectomy, partial) — If sigmoid resection and re-anastomosis is required as part of the diversion, this may be separately reportable with modifier 59 and supporting documentation
- Cystoscopy codes 52000-52010 — Bundled when performed as part of the same operative session for guidance
- Anesthesia — Not reported separately by the operating surgeon
Coding Examples
Example 1 — Ureterosigmoidostomy for Muscle-Invasive Bladder Cancer (Outpatient Physician Claim)
A 61-year-old male with T2 transitional cell carcinoma of the bladder posterior wall, refractory to conservative management, undergoes open radical cystectomy with ureterosigmoidostomy for urinary diversion. The urologist performs both the cystectomy and bilateral ureteral reimplantation into the sigmoid colon using the Leadbetter-Clarke antireflux technique.
Surgeon Report: 51580 (comprehensive code — cystectomy + ureterosigmoidostomy) Do NOT report: 50820 + 51570 separately Principal Diagnosis: C67.4 (Malignant neoplasm of posterior wall of bladder) Secondary Diagnoses: Z17.0 (Estrogen receptor positive status if applicable), relevant comorbidities
⚠️ Common Error: Reporting 50820 and 51570 (cystectomy) separately. The correct code is the bundled 51580, which includes both components. Unbundling these is a NCCI violation.
Example 2 — Isolated Ureterosigmoidostomy Without Cystectomy (Diversion Only)
A 45-year-old female with a severely contracted, fibrotic bladder due to refractory interstitial cystitis and failed intravesical and surgical therapy undergoes ureterosigmoidostomy for urinary diversion. The bladder is left in situ (non-functional but not resected). Bilateral ureters are implanted into the sigmoid colon via submucosal tunnel technique.
Report: 50820 Principal Diagnosis: N30.11 (Interstitial cystitis, chronic, with hematuria) Secondary Diagnoses: N32.89 (Other specified disorders of bladder — contracted bladder)
Example 3 — Ureterosigmoidostomy for Bladder Exstrophy (Pediatric)
A 4-year-old male with classic bladder exstrophy has undergone two prior failed bladder reconstruction attempts. After multidisciplinary discussion, the pediatric urologist performs ureterosigmoidostomy as a salvage diversion. Sphincter continence was confirmed adequate preoperatively via retention enema testing.
Report: 50820 Principal Diagnosis: Q64.10 (Exstrophy of urinary bladder, unspecified) Secondary Diagnoses: Q64.0 (Epispadias, if concurrent), Z87.39 (Personal history of prior genitourinary procedures)
Example 4 — Inpatient with Metabolic Acidosis Complication (CC/MCC Capture)
A 67-year-old male with bladder cancer undergoes ureterosigmoidostomy. On postoperative day 4, he develops hyperchloremic metabolic acidosis with a serum bicarbonate of 16 mEq/L, requiring IV bicarbonate correction and extended hospital stay. Attending physician documents metabolic acidosis due to urinary diversion.
Principal Diagnosis: C67.9 (Malignant neoplasm of bladder, unspecified) Secondary Diagnoses: E87.2 (Acidosis — MCC capture), E87.6 (Hypokalemia, if documented) ICD-10-PCS: 0T1B0ZA (Bypass Bilateral Ureters to Sigmoid Colon, Open) MS-DRG: 673 (Other Kidney and Urinary Tract Procedures with MCC) — driven by E87.2 as MCC
💡 Coding Tip: Without capturing E87.2, this case would group to DRG 675 (without CC/MCC). The metabolic acidosis elevates the case to DRG 673, reflecting the true clinical complexity and significantly increasing reimbursement. Physician query is appropriate if the acidosis is clinically evident in labs but not explicitly documented.
Example 5 — Co-Surgery with Colorectal Surgeon
A urologist and a colorectal surgeon perform ureterosigmoidostomy together, with the colorectal surgeon managing sigmoid mobilization and colostomy formation and the urologist performing ureteral dissection and reimplantation.
Urologist: 50820--62 Colorectal Surgeon: 50820-62 (Each receives approximately 62.5% of the allowable fee)
Example 6 — Return to OR During Global Period
Three weeks after ureterosigmoidostomy, the patient develops a ureteral anastomotic stricture with hydronephrosis and returns to the OR for revision of the anastomosis.
Report: 50820--78 or appropriate revision/repair code with modifier 78 Diagnosis: N13.1 (Hydronephrosis with ureteral stricture) + T83.099A (Other complication of urinary catheter — initial encounter, if stent-related) Note: Modifier 78 indicates return to OR for complication during the global period; reimbursement is reduced
Example 7 — Increased Complexity Modifier
A 72-year-old male with prior low anterior resection for rectal cancer and pelvic radiation undergoes ureterosigmoidostomy. The procedure requires 5.5 hours due to dense pelvic adhesions, radiation fibrosis, and limited sigmoid colon mobility; the operating surgeon documents substantially increased complexity in the operative report.
Report: 50820--22 Diagnosis: C67.9, Z85.038 (History of malignant neoplasm of rectum), Z92.3 (Personal history of irradiation) Note: Modifier 22 requires a detailed operative note and may require a letter of medical necessity to the payer; reimbursement increase typically 20-30% of the allowable
Long-Term Complications — Clinical and Coding Considerations
| Complication | ICD-10-CM Code | HCC | MCC/CC |
|---|---|---|---|
| Hyperchloremic metabolic acidosis | E87.2 | ❌ | ✅ MCC |
| Hypokalemia | E87.6 | ❌ | CC |
| Ascending pyelonephritis | N10 | ❌ | CC |
| Hydronephrosis / ureteral stricture | N13.1 | ❌ | CC |
| Colon carcinoma at anastomosis | C18.7 (sigmoid) | ✅ HCC 15 | MCC |
| CKD progression | N18.4, N18.5 | ✅ HCC 137-138 | CC |
| Malnutrition | E43 | ✅ HCC 21 | MCC |
| Urinary tract infection | N39.0 | ❌ | Neither |
Documentation Tips for Optimal Coding & Reimbursement
- Clearly document whether cystectomy was or was not performed — this determines whether 50820 or 51580 (and related bundled cystectomy codes) applies
- Document which ureters were implanted (unilateral vs. bilateral); bilateral is the norm and is captured within 50820 — do not separately code
- Document the antireflux technique used (Leadbetter-Clarke, Goodwin-Hohenfellner, etc.) for operative record completeness
- Document all comorbidities (metabolic acidosis, CKD, malnutrition, aspiration, diabetes) thoroughly for CC/MCC capture and HCC documentation
- For inpatient cases, ensure ICD-10-PCS codes reflect the correct root operation (Bypass), body part (left ureter, right ureter, or bilateral), approach (Open = 0), device (No Device), and qualifier (Sigmoid Colon = A)
- If pelvic lymphadenectomy is performed concurrently (common in cancer cases), document and report separately: 38770
- Perform physician query whenever metabolic acidosis, electrolyte disturbances, acute kidney injury, or malnutrition are clinically present but not explicitly documented — these carry MCC/CC weight and HCC value
- If modifier 22 is applied, include a detailed operative note paragraph explicitly describing the nature of the increased difficulty and estimated additional time/risk
Related CPT Codes (Cross-Reference)
| CPT | Description |
|---|---|
| 50800 | Ureterointestinal anastomosis, direct |
| 50810 | Ureterosigmoidostomy with sigmoid bladder and colostomy |
| 50815 | Ureterocolon conduit with intestine anastomosis |
| 50825 | Continent diversion (Indiana/Kock pouch) with intestine anastomosis |
| 50830 | Urinary undiversion |
| 50840 | Replacement of ureter by intestine segment |
| 51580 | Cystectomy, complete; with Ureterosigmoidostomy (bundled) |
| 51585 | Cystectomy, complete; with ureterosigmoidostomy + lymphadenectomy |
| 38770 | Pelvic lymphadenectomy (separately reportable) |
| 44140 | Colectomy, partial (sigmoid resection — separately reportable if required) |
| 50947 | Laparoscopic ureteroneocystostomy |
| 52000 | Cystourethroscopy |
Quick Reference Summary
| Field | Detail |
|---|---|
| CPT | 50820 |
| Full Descriptor | Ureterosigmoidostomy, with or without cystectomy |
| Approach | Open |
| wRVU | 20.32 |
| Global Period | 90 days |
| Assistant Payable | ✅ Yes |
| Facility Only | ✅ Yes |
| Primary ICD-10 | C67.9, Q64.10, N31.9 |
| HCC Diagnoses | C67.x → HCC 11/17; N18.4-N18.6 → HCC 136-138 |
| Top MCC Diagnoses | E87.2 (acidosis), N18.6 (ESRD), C67.x (bladder cancer) |
| MS-DRG | 673 / 674 / 675 |
| Bundled Code | 51580 when cystectomy included |
| Do NOT Unbundle | 50820 + 51570 — use 51580 instead |
| Commonly Confused With | 50825 (continent diversion), 51580 (cystectomy + diversion bundled) |