🧬CPT 50610 - Ureterolithotomy; Upper One-Third of Ureter

📋 Full Code Description

Ureterolithotomy; upper one-third of ureter

This code describes an open surgical ureterolithotomy — the direct incisional removal of a calculus (stone) from the upper one-third of the ureter via an open retroperitoneal or transperitoneal approach. The surgeon makes a flank or abdominal incision, identifies and exposes the ureter retroperitoneally, incises the ureteral wall directly over the stone (ureterotomy), extracts the calculus under direct vision, and closes the ureterotomy — typically with absorbable sutures — with or without ureteral stent placement.

50610 is one of three location-stratified ureterolithotomy codes, each defined by the anatomical third of the ureter containing the stone:

50610 — Upper one-third of ureter (proximal ureter; UPJ to the level of the iliac vessels)
50620 — Middle one-third of ureter (crossing the iliac vessels)
50630 — Lower one-third of ureter (distal ureter; iliac vessels to the ureterovesical junction/UVJ)

The upper third corresponds anatomically to the segment from the ureteropelvic junction (UPJ) inferiorly to approximately the upper border of the sacrum or the level where the ureter crosses the iliac vessels, depending on the reference used. This is the retroperitoneal segment that runs along the medial border of the psoas muscle, anterior to the transverse processes of the lumbar vertebrae.

⚠️ Rarity in modern practice: Open ureterolithotomy has become an exceptionally rare procedure. The advent of flexible ureteroscopy (52352, 52356), ureteroscopic lithotripsy, and extracorporeal shockwave lithotripsy (50590) has displaced open surgical stone removal in virtually all circumstances. 50610 is retained in CPT primarily for cases involving extremely large, impacted, or complex proximal ureteral stones where endoscopic approaches have failed, for patients in whom intracorporeal lithotripsy is contraindicated, or in resource-limited settings where endoscopic technology is unavailable. It may also appear in robotic/laparoscopic-to-open conversion scenarios.

🔬 Anatomy: The Upper One-Third of the Ureter

Feature	Detail
Segment	Proximal ureter — from the ureteropelvic junction (UPJ) to approximately the level of the sacral promontory or where the ureter crosses anterior to the common iliac artery
Length	The total ureter is ~25-30 cm; the upper third is approximately the superior 8-10 cm
Location	Retroperitoneal; runs medially along the psoas major muscle
Anterior relations (right)	Duodenum, right colic vessels, ileocolic vessels; gonadal vessels cross anterior
Anterior relations (left)	Left colic vessels, sigmoid mesocolon; gonadal vessels cross anterior
Blood supply	Multiple segmental branches from the renal artery, aorta, and gonadal arteries; watershed zones exist and dictate closure technique
Points of natural narrowing	UPJ (most common proximal stone lodgment site), where ureter crosses iliac vessels, UVJ
Stone lodgment	Calculi most frequently impact at natural narrowing points; at the UPJ level for upper-third stones
Surgical approach	Typically a flank or dorsal lumbotomy incision for upper-third ureterolithotomy; occasionally a midline laparotomy for complex cases

🏥 Code Placement in the CPT Hierarchy

Level	Description
Section	Surgery
Subsystem	Urinary System
Sub-subsection	Ureter
Procedure type	Incision / Biopsy Procedures on the Ureter
Sub-range	Ureterolithotomy
Code	50610
Range	50610-50630

🌳 Code Tree / Family

Surgical Procedures — Ureter
│
├── OPEN Ureterolithotomy (Location-Stratified)
│   ├── [[50610]] — Ureterolithotomy; UPPER one-third of ureter ← THIS CODE
│   │               ↳ UPJ to iliac vessel crossing
│   │               ↳ Flank/retroperitoneal approach
│   │               ↳ wRVU ~11.60 | Global: 090 days | Major surgery
│   │               ↳ Rarely performed; largely supplanted by endoscopy
│   │
│   ├── [[50620]] — Ureterolithotomy; MIDDLE one-third of ureter
│   │               ↳ At or near iliac vessel crossing
│   │               ↳ wRVU ~11.60 (comparable) | Global: 090 days
│   │
│   └── [[50630]] — Ureterolithotomy; LOWER one-third of ureter
│                   ↳ Iliac vessels to UVJ (juxtavesical ureter)
│                   ↳ Often approached via lower abdominal/Gibson incision
│                   ↳ wRVU ~12.30 (slightly higher; more complex exposure) | Global: 090 days
│
├── LAPAROSCOPIC Ureterolithotomy
│   └── [[50945]] — Laparoscopy, surgical; ureterolithotomy
│                   ↳ Laparoscopic approach to ureteral stone removal
│                   ↳ More common than open; less common than ureteroscopy
│                   ↳ wRVU ~13.06 | Global: 090 days
│
├── ENDOSCOPIC Ureteral Stone Management (Modern Standard of Care)
│   ├── [[52352]] — Ureteroscopy with lithotripsy and/or stone manipulation (no basket)
│   │               ↳ wRVU ~9.98 | Most common approach for ureteral stones
│   │
│   ├── [[52353]] — Ureteroscopy with lithotripsy (no basket)
│   │
│   ├── [[52356]] — Ureteroscopy with lithotripsy and basket extraction
│   │               ↳ wRVU ~12.02 | Includes simultaneous stone extraction
│   │
│   └── [[52332]] — Cystourethroscopy with insertion of indwelling ureteral stent
│                   ↳ May be used alone or as adjunct to stone procedures
│
├── ESWL (Extracorporeal Shockwave Lithotripsy)
│   └── [[50590]] — ESWL, renal and/or ureteral calculus (unilateral)
│                   ↳ wRVU ~5.52 | Non-invasive; effective for smaller proximal stones
│
└── PERCUTANEOUS Procedures (for renal/proximal ureteral stones)
    ├── [[50080]] — PCNL; up to 2 cm stone
    │               ↳ wRVU ~18.82
    └── [[50081]] — PCNL; stone >2 cm
                    ↳ wRVU ~24.41

⚙️ Technical Details

Field	Detail
Global Period	090 — 90-day global surgical package (major surgery)
wRVU (Work RVU)	~11.60 (verify current value via CMS MPFS Addendum B; rarely surveyed due to low volume)
Total RVU (Facility, est.)	~14.00-16.00 (estimated; geographically adjusted)
2025 Medicare MPFS Facility Payment	~ $453 -$ 517 (national average, geographically adjusted; 2025 CF $32.35)
PC/TC Indicator	N/A — surgical procedure; no professional/technical split
Assistant Surgeon Payable	✅ Yes — Medicare assistant surgeon indicator: 2 (payable; major open surgical case). - 80 for MD assistant; -AS for PA/NP/CNS assistant. Verify per individual MAC policy.
Co-Surgeon Payable	Generally not applicable for standard unilateral ureterolithotomy
Bilateral Indicator	1 — 150% rule applies if performed bilaterally (extremely rare); use modifier -50
Separate Procedure Designation	❌ No
Major Surgery	✅ Yes — 90-day global period
MUE	1 unit per date of service
Usual Place of Service	POS 21 (Inpatient Hospital), POS 22 (Outpatient Hospital), POS 24 (ASC — less common for open approach)
Anesthesia	General or regional (spinal/epidural); administered by separate anesthesiology team
Typical OR Time	1.5-3 hours depending on stone impaction, adhesions, and patient anatomy
Conversion Factor (2025)	$32.35
Clinical frequency	Very low in contemporary urology — this is a rarely billed code in modern practice

🔬 Step-by-Step Operative Overview

PATIENT — Upper Ureteral Calculus (UPJ to iliac vessel level)
        │
        ▼
STEP 1: Positioning
  - Patient placed in lateral decubitus (flank) position (ipsilateral side up)
  - Kidney rest elevated; table flexed to open flank space
  - Alternatively: supine for transperitoneal approach (less common)
        │
        ▼
STEP 2: Incision
  - Flank incision: 11th or 12th rib approach; retroperitoneal access
  - Alternatively: dorsal lumbotomy (posterior approach; less common)
  - Layers divided: skin → subcutaneous → external oblique → internal oblique 
    → transversus abdominis → Gerota's fascia
        │
        ▼
STEP 3: Retroperitoneal Exposure
  - Peritoneum swept medially to expose retroperitoneal space
  - Ureter identified by its peristalsis, white fibromuscular wall, and medial 
    position on psoas muscle
  - Gonadal vessels identified and retracted
        │
        ▼
STEP 4: Stone Localization
  - Ureter palpated for stone; stone confirmed by feel (firm, non-compressible 
    bulge within ureter lumen)
  - Stay sutures placed proximal and distal to stone to prevent migration
        │
        ▼
STEP 5: Ureterotomy
  - Longitudinal or transverse incision made directly over stone with 
    fine-tipped scissors or scalpel
  - Stone extracted intact with a stone forceps or loop
  - Ureteral lumen inspected proximally and distally; irrigation performed to 
    confirm passage and absence of additional fragments
        │
        ▼
STEP 6: Stenting (Optional but Common)
  - Double-J ureteral stent placed under direct vision across ureterotomy site
  - Stent ensures urinary drainage during ureterotomy healing
  - Not always required for clean, primary closures
        │
        ▼
STEP 7: Ureterotomy Closure
  - Closed with interrupted absorbable sutures (e.g., 4-0 Vicryl or PDS) 
    in watertight fashion
  - Retroperitoneal drain placed near ureterotomy site
        │
        ▼
STEP 8: Closure
  - Fascial layers closed in anatomic layers
  - Skin closed per surgeon preference
  - Drain brought through separate stab incision

✅ What This Code Includes

Preoperative patient positioning and surgical preparation
Flank, dorsal lumbotomy, or abdominal incision for retroperitoneal ureteral access
Retroperitoneal dissection to identify and expose the upper ureter
Placement of proximal and distal stay sutures to prevent stone migration
Ureterotomy (incision of the ureteral wall) directly over the calculus
Stone extraction under direct visualization
Ureteral irrigation to verify lumen patency and absence of residual fragments
Ureterotomy closure with absorbable sutures
Retroperitoneal drain placement
Wound closure in anatomic layers
Intraoperative specimen handling (stone sent for compositional analysis)
90-day post-operative global surgical package (all related post-op visits for 90 days)
Ureteral stent placement (when performed as part of the same operative session by the same surgeon — see Excludes section for nuance)

❌ What This Code Does NOT Include / Excludes

Cystoscopic ureteral stent placement billed separately — if the surgeon places a ureteral stent via separate cystoscopy at a different session (e.g., post-op stent check), this may be reported with the appropriate cystoscopy/stent code with modifier -78 or -79 depending on relationship to the global period; do NOT separately bill stent placement if it occurs during the same operative session as 50610
Ureteroscopy — endoscopic ureteral stone management uses entirely different codes (52352, 52353, 52356); 50610 is open surgery only
Laparoscopic approach — that is 50945; 50610 is open surgical approach only
Contralateral (opposite side) ureteral stone removal — requires a separate code (e.g., 50610 -RT or -LT for each side, with -50 for bilateral if simultaneous); two distinct procedures on different ureters cannot be bundled into one unit of 50610
Renal pelvis stone removal — if the stone is at or above the UPJ (in the renal pelvis), codes 50060-50075 (nephrolithotomy/pyelolithotomy) are more appropriate depending on approach
PCNL — percutaneous approaches are 50080/50081
Nephrectomy — if the kidney is non-functional and removed along with the stone-containing ureter, use the appropriate nephrectomy code
Anesthesia — billed separately by anesthesiology
Post-operative ureteral stent removal — stent removal during the 90-day global period is included; if the stent was placed at the time of surgery, its removal is bundled into the global period
Retrograde pyelography — if performed intraoperatively to confirm stone position or residual fragments, may be separately billable; verify NCCI edits
Stone compositional analysis — billed by the laboratory separately

🔢 NCCI / Bundling Edits (Partial)

Code	Description	Edit Type
50620	Ureterolithotomy, middle third	Mutually exclusive same side — different segment indicates a different stone; cannot report both for same ureter same session unless distinct, separately documented stones in different ureteral segments
50630	Ureterolithotomy, lower third	Same as above — mutually exclusive for same ureter same session
50945	Laparoscopic ureterolithotomy	Mutually exclusive — cannot report open and laparoscopic approaches for same stone same session
52352	Ureteroscopy with lithotripsy	Column 1/Column 2 — endoscopic approach bundles with open if performed same session for same stone
52356	Ureteroscopy, lithotripsy + basket	Column 1/Column 2 — same
50590	ESWL	Cannot report ESWL for same stone same session as open surgical removal
49320	Diagnostic laparoscopy	If diagnostic laparoscopy performed prior to decision for open ureterolithotomy, 49320 may be separately reportable with -59 if documented as a distinct service

⚠️ This is a representative list. Always verify the full CMS NCCI PTP edit table for current edits. NCCI edits are updated quarterly.

🏷️ Applicable Modifiers

Modifier	Name	Application to 50610
-LT	Left Side	Most commonly used modifier — when ureterolithotomy is performed on the left ureter; required by Medicare and most payers to establish laterality
-RT	Right Side	When ureterolithotomy is performed on the right ureter; required for laterality
-50	Bilateral Procedure	Extremely rare — when simultaneous bilateral upper ureteral stone removal is performed; payment at 150% of the single-side allowance. Requires two stones, one in each upper ureter. Document each side clearly.
-22	Increased Procedural Services	When the procedure is substantially more complex than typical — e.g., severely impacted stone requiring extensive ureterolysis, dense retroperitoneal fibrosis, prior radiation, ureteral necrosis, or intraoperative complications requiring complex repair. Must be supported by detailed operative report documentation.
-52	Reduced Services	When the ureterolithotomy is initiated but cannot be completed (e.g., stone migrates retrograde into the renal pelvis during dissection; converted to a different procedure)
-53	Discontinued Procedure	When the procedure is stopped after initiation due to patient safety concerns before meaningful surgical work is completed
-54	Surgical Care Only	When the urologist performs the surgery but transfers post-operative care to another provider; 90-day global period splits accordingly
-55	Postoperative Management Only	When a provider assumes post-operative management from the operating urologist during the 90-day global period
-57	Decision for Surgery	Appended to the E/M code (not 50610) when the decision to operate is made at the same visit as the procedure (90-day global = major surgery; -57 applies to the E/M on the day of or day before surgery)
-58	Staged/Related Procedure During Global Period	When a related planned procedure is performed during the 90-day global period (e.g., planned stent removal with cystoscopy that requires additional therapeutic work)
-62	Two Surgeons	When the complexity of the case requires two surgeons of different specialties performing distinct portions (rare for standard ureterolithotomy; may apply in complex cases involving bowel, vascular, or gynecologic structures)
-76	Repeat Procedure, Same Physician	If the ureterolithotomy must be repeated on the same date
-78	Unplanned Return to OR, Same Physician	When the patient returns to the OR during the 90-day global period for a related complication (e.g., ureteral stricture, urine leak, bleeding requiring re-exploration)
-79	Unrelated Procedure During Global Period	For a new, unrelated procedure performed during the 90-day global period
-80	Assistant Surgeon	Standard MD assistant surgeon modifier; Medicare indicator 2 (payable); payer-specific verification required
-AS	PA/NP/CNS as Assistant Surgeon	Non-physician practitioner assistant; payer-specific

🏥 MS-DRG Applicability

CPT 50610 is an outpatient/professional billing code. In the inpatient setting, procedures are reported using ICD-10-PCS codes, not CPT codes.

ICD-10-PCS Equivalent Codes for Inpatient Open Ureterolithotomy

The ICD-10-PCS root operation for stone removal from the ureter is Extirpation (C) — “Taking or cutting out solid matter from a body part.”

ICD-10-PCS Code	Description
0TC60ZZ	Extirpation of Matter from Right Ureter, Open Approach
0TC70ZZ	Extirpation of Matter from Left Ureter, Open Approach
0TC80ZZ	Extirpation of Matter from Bilateral Ureters, Open Approach

📌 If the open ureterolithotomy is performed laparoscopically (50945), the approach character changes to 4 (Percutaneous Endoscopic):

0TC64ZZ — Extirpation of Matter from Right Ureter, Percutaneous Endoscopic Approach

0TC74ZZ — Extirpation of Matter from Left Ureter, Percutaneous Endoscopic Approach

MS-DRG Groupings for Inpatient Ureterolithotomy

When open ureterolithotomy is performed as an inpatient procedure (an OR procedure), the case groups to the surgical DRGs within MDC 11 (Diseases and Disorders of the Kidney and Urinary Tract) — specifically the Kidney and Ureter Procedures for Non-Neoplasm triplet, rather than the medical urinary stone DRGs (693/694):

MS-DRG	Description	Notes
659	Kidney and Ureter Procedures for Non-Neoplasm with MCC	Applies when open ureteral surgery + MCC (e.g., sepsis, respiratory failure, renal failure)
660	Kidney and Ureter Procedures for Non-Neoplasm with CC	Applies when + CC (e.g., hypertension, CHF, UTI, ureteral stricture)
661	Kidney and Ureter Procedures for Non-Neoplasm without CC/MCC	Straightforward stone removal, no significant comorbidities

Medical (Non-Surgical) Urinary Stone DRGs (when no qualifying O.R. procedure is performed):

MS-DRG	Description	Notes
693	Urinary Stones with MCC	Non-operative management of urinary calculi with significant comorbidity; NOT used when open surgical procedure is performed
694	Urinary Stones without MCC	Non-operative or ESWL-treated urinary calculi

💡 Key distinction for facility coding: When an open ureterolithotomy (0TC60ZZ or 0TC70ZZ) is the principal procedure in an inpatient stay, the case will group to DRG 659/660/661, NOT to 693/694. The surgical DRGs carry significantly higher relative weights and reimbursement. Accurate ICD-10-PCS coding of the open procedure is critical to appropriate DRG assignment.

Estimated 2025 IPPS Payments:

MS-DRG	Geometric Mean LOS	Relative Weight (est.)	Estimated National Payment
659 (w/ MCC)	~7.2 days	~3.84	~ $22, 000 -$ 26,000
660 (w/ CC)	~4.1 days	~2.15	~ $12, 000 -$ 15,000
661 (w/o CC/MCC)	~2.1 days	~1.38	~ $8, 000 -$ 10,000

⚠️ Geometric mean LOS and relative weights are approximate and subject to annual IPPS revision. Verify via the current CMS IPPS Final Rule Tables.

🩺 Associated ICD-10-CM Diagnosis Codes

💡 Coding tip: The primary diagnosis for 50610 is almost always a ureteral calculus code. Code the stone location (ureter) as the primary finding, and add secondary codes for any complications (obstruction, hydronephrosis, infection, renal insufficiency) and metabolic causes (gout, hyperparathyroidism, etc.).

🪨 Primary Ureteral Calculus Codes (Core Indications for 50610)

ICD-10-CM	Description	HCC	CC/MCC	Notes
N20.1	Calculus of ureter	None	CC	Most common primary dx for 50610; ureteral stone without concurrent renal stone
N20.2	Calculus of kidney with calculus of ureter	None	CC	When both a renal stone and ureteral stone are present (same side); code this when both are documented
N20.0	Calculus of kidney	None	CC	Renal calculus; use when the stone is at the UPJ level and has elements of both renal pelvis and ureter involvement; or when a renal stone migrated into the upper ureter
N20.9	Urinary calculus, unspecified	None	CC	Least specific; avoid when location is known
N21.8	Other lower urinary tract calculus	None	None	Not appropriate for ureteral stones

💡 N20.1 vs N20.2: Use N20.2 only when there is documentation of both a renal calculus AND a ureteral calculus (same episode). If the stone originated in the kidney and migrated to the upper ureter, use N20.1 for the ureteral stone location at the time of surgical treatment.

🌊 Hydronephrosis and Ureteral Obstruction (Common Associated Diagnoses)

ICD-10-CM	Description	HCC	CC/MCC	Notes
N13.2	Hydronephrosis with renal and ureteral calculous obstruction	None	CC	Use when hydronephrosis is documented in conjunction with the calculus; this code captures the obstructive element
N13.1	Hydronephrosis with ureteral stricture, NEC	None	CC	If hydronephrosis is from stricture (not stone)
N13.30	Unspecified hydronephrosis	None	CC	When hydronephrosis is documented without specification of cause
N13.39	Other hydronephrosis	None	CC
N13.6	Pyonephrosis	None	MCC	Infected, obstructed kidney — signifies septic complication; major clinical escalation; shifts DRG to MCC category

⚠️ N13.6 (Pyonephrosis): When ureteral stone causes complete obstruction with infected urine backing into the kidney, pyonephrosis may develop. Coding this when documented is critical — it qualifies as an MCC and will shift the inpatient DRG from 661 → 659, with a reimbursement impact of ~ $12, 000 -$ 16,000 per case.

🦠 Infection / UTI / Urosepsis (Complicating Diagnoses)

ICD-10-CM	Description	HCC	CC/MCC	Notes
N10	Acute pyelonephritis	None	CC	Upper tract infection often present with obstructing ureteral stone
N12	Tubulo-interstitial nephritis, not specified as acute or chronic	None	CC
N30.00	Acute cystitis without hematuria	None	None	Lower tract infection
N30.01	Acute cystitis with hematuria	None	None
N39.0	Urinary tract infection, site not specified	None	None	Non-specific; use only if site truly indeterminate
A41.9	Sepsis, unspecified organism	HCC 2	MCC	Urosepsis due to obstructing ureteral stone is a major clinical complication; code as sepsis when criteria are met (SIRS + suspected/confirmed infection)
A41.51	Sepsis due to Escherichia coli	HCC 2	MCC	When specific organism identified
A41.59	Other Gram-negative sepsis	HCC 2	MCC
B96.20	Unspecified E. coli as the cause of diseases classified elsewhere	None	None	Secondary code for organism when sepsis criteria not met

🩺 Renal Function Impairment (Secondary Diagnoses)

ICD-10-CM	Description	HCC	CC/MCC	Notes
N17.9	Acute kidney injury, unspecified	None	MCC	Obstructive uropathy from ureteral stone may cause post-renal AKI; MCC when documented
N17.0	AKI with tubular necrosis	None	MCC	If prolonged obstruction led to tubular damage
N18.3-	Chronic kidney disease, stage 3 (moderate)	HCC 138	CC	Pre-existing CKD relevant to surgical decision-making and anesthesia risk
N18.4	CKD, stage 4 (severe)	HCC 138	CC
N18.5	CKD, stage 5	HCC 136	MCC
N18.6	End-stage renal disease	HCC 136	MCC
N18.9	CKD, unspecified	HCC 138	CC
N19	Unspecified kidney failure	None	CC

🧬 Metabolic / Underlying Causes of Urolithiasis

ICD-10-CM	Description	HCC	CC/MCC	Notes
E79.0	Hyperuricemia without signs of inflammatory arthritis	None	None	Uric acid stone disease; code if documented as etiology
E79.00	Gout, unspecified	None	None
M10.9	Gout, unspecified	None	None
E83.51	Hypercalcemia	None	CC	Elevated calcium → calcium oxalate/phosphate stones
E21.0	Primary hyperparathyroidism	None	CC	Leading endocrine cause of recurrent calcium nephrolithiasis
E21.3	Hyperparathyroidism, unspecified	None	CC
E72.11	Homocystinuria	None	None	Cystinuria → cystine stone disease
E72.19	Other disorders of amino-acid transport	None	None
N25.81	Secondary hyperparathyroidism of renal origin	None	CC
K72.11	Chronic hepatic failure with coma	HCC 27	MCC	Hyperoxaluria from hepatic disease → calcium oxalate stones
E74.818	Other specified disorders of carbohydrate metabolism	None	None	Includes primary hyperoxaluria variants
Z87.442	Personal history of urinary calculi	None	None	Secondary code; documents recurrent stone history

🏥 Post-Procedural Complications (Global Period Returns)

ICD-10-CM	Description	HCC	CC/MCC	Notes
N99.520	Hemorrhage of ureter following procedure	None	CC	Ureteral bleeding post-ureterolithotomy
N99.521	Bleeding of right ureter following a procedure	None	CC	Laterality-specific
N99.522	Bleeding of left ureter following a procedure	None	CC
N99.89	Other postprocedural complications/disorders of genitourinary system	None	CC
T83.518A	Infection of indwelling ureteral stent, initial encounter	None	CC	Stent infection post-procedure
N13.5	Kinking and stricture of ureter without hydronephrosis	None	CC	Post-operative ureteral stricture
Z48.23	Encounter for aftercare following kidney transplant	None	None	Not applicable here but listed for reference
Z53.31	Laparoscopic procedure converted to open	None	None	When 50945 was attempted and converted to 50610

🎯 HCC (Hierarchical Condition Category) Notes

⚕️ HCC categories apply to ICD-10-CM diagnosis codes only — not CPT codes.

HCC	Category	Relevant Codes	RAF Impact
HCC 2	Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock	A41.9, A41.51, A41.59	~0.979 (significant)
HCC 136	Chronic Kidney Disease Stage 5 / ESRD	N18.5, N18.6	~0.289
HCC 138	Chronic Kidney Disease, Moderate Stage (3 and 4)	N18.3-, N18.4, N18.9	~0.106
HCC 27	End-Stage Liver Disease	Relevant if hepatic oxaluria	~0.979

Key HCC documentation notes:

The primary calculus codes (N20.1, N20.2, N20.0) do NOT carry HCC weight. The HCC implications of a 50610 encounter come entirely from complicating secondary diagnoses — most importantly, sepsis, AKI, pyonephrosis, and CKD.
For Medicare Advantage patients with CKD + urinary stone disease, ensuring CKD is coded at the most specific stage documented (N18.3-, N18.4, etc.) is critical for HCC 138 capture. This should be coded at every qualifying encounter.
Sepsis from urosepsis (A41.9, HCC 2) is commonly under-documented in stone cases. When a patient with an obstructing stone meets sepsis criteria (SIRS + infection source), coding A41.9 + N10 (pyelonephritis) is appropriate. This has both HCC RAF impact and significant DRG (MCC) implications.
AKI (N17.9, MCC) is frequently present in complete obstruction cases but is under-coded. CDI queries should be considered for any patient with elevated creatinine and an obstructing stone.

💡 Clinical Context: When Is 50610 Still Performed?

Despite the near-total replacement of open ureterolithotomy by minimally invasive techniques, 50610 remains clinically relevant in the following scenarios:

Clinical Scenario	Why Open Approach May Be Necessary
Massive impacted proximal ureteral stone (>2 cm)	Too large and/or too impacted for ureteroscopic extraction or ESWL fragmentation
Failed ureteroscopic attempts	Dense impaction, tortuous ureter, inaccessible stone despite multiple endoscopic tries
Concurrent open abdominal surgery	If the patient is already undergoing open abdominal/retroperitoneal surgery, stone removal may be added to the same operative session
Retroperitoneal fibrosis or severe adhesions	Endoscopic approach is contraindicated or ineffective
Ureteral stricture requiring open repair + stone removal	When the stricture causing obstruction also requires open correction (ureteroplasty, ureteroureterostomy)
Resource-limited settings	Ureteroscopy equipment unavailable
Robotic/laparoscopic conversion	50945 attempted but converted to open due to intraoperative findings
Very large struvite (staghorn extension) stones	Stone burden extending from renal pelvis into upper ureter

📋 Required Operative Report Elements for 50610

A compliant and audit-ready operative report must include:

Pre-operative diagnosis — ureteral calculus with location (upper third/left or right), size, and clinical consequence (obstruction, pain, UTI)
Post-operative diagnosis — confirmed findings; may differ if stone not found in expected location
Intent and approach — explicitly stated as “open ureterolithotomy”; incision type (flank, dorsal lumbotomy, etc.)
Anesthesia type — general or regional
Patient positioning — lateral decubitus (flank), supine, etc.
Ureteral exposure — detailed description of retroperitoneal dissection steps, structures encountered, peritoneum reflected, gonadal vessels identified and protected
Stone identification — method of stone confirmation (palpation, intraoperative radiograph if used), size, and appearance
Stay suture placement — documented proximal and distal to stone
Ureterotomy — length, orientation (longitudinal vs. transverse), and location within the upper ureter
Stone extraction — instrument used, intactness of stone, disposition (sent for compositional analysis)
Lumen assessment — proximal and distal ureteral irrigation; passage confirmed; no residual fragments
Stent placement — documented if performed; size and type of stent
Ureterotomy closure — suture type, technique (interrupted vs. running), watertight status
Drain placement — type, size, and exit site
Closure — anatomic layer-by-layer closure, skin closure technique
Complications — none or described in detail (inadvertent enterotomy, vascular injury, ureteral avulsion, etc.)

⚠️ Audit risk: Operative reports for rare, high-value open procedures like 50610 receive heightened scrutiny. A complete, detailed operative report is essential. Vague documentation (e.g., “ureter exposed, stone removed, closed”) is insufficient and will not withstand audit.

🧾 Coding Examples

Example 1 — Straightforward Upper Left Ureteral Stone, Open Removal

A 48-year-old male with a 1.5 cm impacted upper-third left ureteral stone, failed ureteroscopy ×2, presents for open ureterolithotomy. Left flank incision, retroperitoneal exposure. Stone confirmed by palpation just below the UPJ. Stay sutures placed. Longitudinal ureterotomy performed; 1.5 cm calcium oxalate stone extracted intact. Double-J stent placed. Ureterotomy closed with 4-0 Vicryl interrupted sutures. JP drain placed. Z53.31 not applicable (no laparoscopic attempt this session).

CPT: 50610 -LT ICD-10-CM: N20.1 (calculus of ureter), N13.2 (hydronephrosis with calculous obstruction) Global: 90-day package begins day of surgery

Example 2 — Right Upper Ureteral Stone with Urosepsis and AKI

A 62-year-old female presents emergently with right ureteral stone (upper third, 1.2 cm), febrile, septic (temp 39.2°C, WBC 18K, HR 118, hypotension responsive to fluids), AKI (Cr 2.8 from baseline 0.9). Nephrostomy tube placed urgently; 48 hours later, open right ureterolithotomy performed. Flank incision; dense retroperitoneal edema from prior infection. Extensive dissection required. Stone extracted; stent placed; drain placed.

CPT: 50610 -RT -22 (extensive/complex dissection due to retroperitoneal inflammation from sepsis; document operative time and complexity) ICD-10-CM: N20.1, A41.9 (sepsis — MCC), N10 (acute pyelonephritis), N17.9 (AKI — MCC), N13.6 (pyonephrosis — MCC) MS-DRG (inpatient): 659 — Kidney and Ureter Procedures for Non-Neoplasm with MCC (multiple MCCs: sepsis + AKI + pyonephrosis) ICD-10-PCS: 0TC40ZZ right ureter extirpation, open (verify body part character for right)

Example 3 — Bilateral Upper Ureteral Stones, Simultaneous Open Removal

A 35-year-old male with cystinuria and bilateral upper ureteral calculi (right 1.8 cm, left 1.3 cm), both impacted, presents after failed ESWL. Simultaneous open bilateral ureterolithotomy performed via midline laparotomy for bilateral retroperitoneal access. Both stones extracted; bilateral double-J stents placed.

CPT: 50610 -50 (bilateral; 150% rule) ICD-10-CM: N20.1 (bilateral implied by laterality documentation), E72.19 (cystinuria — documented metabolic etiology) Note: Bilateral stones in the same anatomic segment billed as 50610 -50; some payers prefer 50610 -LT + 50610 -RT -51 — verify payer preference

Example 4 — Open Ureterolithotomy After Laparoscopic Conversion

A 55-year-old male planned for laparoscopic ureterolithotomy (50945). Intraoperatively, retroperitoneal fibrosis from prior sigmoid surgery prevents safe laparoscopic dissection. Procedure converted to open after 25 minutes of laparoscopic work.

CPT: 50610 -LT (the completed open procedure) ICD-10-CM: N20.1, K66.0 (peritoneal adhesions), Z53.31 (laparoscopic procedure converted to open) Note: 50945 is NOT reported separately — only the completed procedure (50610) is billed. Z53.31 documents the conversion for quality tracking and audit context.

Example 5 — Return to OR During Global Period for Ureteral Stricture

A patient underwent 50610 -LT 18 days ago (within 90-day global period). Returns with left ureteral obstruction due to post-ureterotomy stricture. Taken to OR for cystoscopy, retrograde pyelogram, and ureteral balloon dilation.

CPT: 52000 -78 (cystoscopy for related complication during global period) + 52341 -78 (treatment of ureteral stricture, endoscopic) ICD-10-CM: N13.5 (kinking and stricture of ureter), N99.89 (postprocedural complications, GU system) Modifier -78 on both codes — return to OR for complication during global period; payment for intraoperative portion only (~70% of allowable)

Example 6 — Inpatient ICD-10-PCS Coding (Facility Coder)

Inpatient admission for left upper ureteral calculus with hydronephrosis and acute pyelonephritis. Open left ureterolithotomy performed.

ICD-10-PCS: 0TC70ZZ (Extirpation of Matter from Left Ureter, Open Approach) ICD-10-CM Principal Dx: N20.1 (calculus of ureter) Secondary Dx: N13.2 (hydronephrosis with calculous obstruction — CC), N10 (acute pyelonephritis — CC) MS-DRG: 660 — Kidney and Ureter Procedures for Non-Neoplasm with CC

Example 7 — Upper Ureteral Stone + Concurrent Ureteral Stent Placement (Same Session)

Open right upper ureterolithotomy performed. At the conclusion of the procedure, the surgeon places a Double-J ureteral stent via direct vision through the ureterotomy before closure.

CPT: 50610 -RT only Do NOT add: 52332 (stent placement) — the ureteral stent placement performed in the same operative field during the same session is included in 50610 and cannot be separately billed Exception: If a cystoscopic or ureteroscopic stent placement is performed at a separate session (e.g., stent placed pre-operatively or post-operatively via cystoscopy), it may be separately reportable with the appropriate modifier

🔄 Comparison: 50610 vs. 50945 vs. 52352 vs. 52356 vs. 50590

Feature	50610	50945	52352	52356	50590
Approach	Open	Laparoscopic	Ureteroscopic	Ureteroscopic	Non-invasive (ESWL)
Stone location	Upper ureter	Any ureter	Ureter/kidney	Ureter/kidney	Ureter/kidney
Anesthesia	General/regional	General	General/spinal	General/spinal	Sedation/general
wRVU	~11.60	~13.06	~9.98	~12.02	~5.52
Global	090	090	010	010	010
Hospital stay	Typically 1-3 days	1-2 days	Outpatient	Outpatient	Outpatient
Modern frequency	Very rare	Uncommon	Very common	Very common	Common
Best for	Failed endoscopy, massive/complex stones	Failed ureteroscopy, complex cases	Routine ureteral stones	Ureteral stones needing basket extraction	Small/medium proximal stones
Stone size limit	None	None	Fragmentation required for large stones	With lithotripsy + basket	Best for <2 cm
Assistant surgeon	✅ Yes (indicator 2)	Payer-specific	❌ Typically not	❌ Typically not	❌ No

⚠️ Common Coding Pitfalls

Confusing location stratification: 50610 vs. 50620 vs. 50630 — the most fundamental error. The code must match the documented ureteral segment. Upper third = 50610. If the operative report states “lower ureter” or “distal ureter,” use 50630. If the location is unclear, query the surgeon. Do not default to 50610.
Not appending -LT or -RT — Medicare and most payers require laterality modifiers for ureteral procedures. Omission will result in denial. This is the most common billing error for urological stone codes.
Billing 50610 with 52352 or 52356 for the same stone same session — NCCI bundling prevents reporting both open surgical removal and endoscopic ureteroscopy for the same stone in the same operative session. If a ureteroscopy was attempted and then the surgeon converted to open, only the completed (open) procedure is billed.
Reporting stent placement separately when performed during the same open session — ureteral stent insertion (52332) done concurrently during the open ureterolithotomy is included in 50610 and cannot be separately reported in the same session.
Using 50610 for laparoscopic ureterolithotomy — 50610 is open surgery only. Laparoscopic ureteral stone removal = 50945.
Not documenting stone segment location in the operative report — the operative report must clearly state the location as “upper one-third” or anatomically equivalent documentation (e.g., “below the UPJ, above the iliac vessel crossing”) to support 50610 vs. 50620 vs. 50630.
Under-coding secondary diagnoses in the inpatient setting — Ureteral stone patients admitted inpatient often have significant comorbidities (hydronephrosis, pyonephrosis, AKI, sepsis, CKD) that carry CC or MCC status. Missing these codes is a major DRG revenue loss. CDI teams should flag all stone cases for complication/comorbidity documentation and coding completeness.
Applying -22 without detailed documentation — if the procedure was substantially more complex (e.g., retroperitoneal fibrosis, massive impaction, emergency conversion), modifier -22 is appropriate but requires a narrative in the operative report explaining what made the case exceptional. Simply noting “difficult dissection” is insufficient.
Billing 50610 and 50620 for the same ureter same session — these codes are mutually exclusive for the same ureteral segment in the same session. A stone that spans the border of the upper and middle third is coded to the anatomic third where the majority of the stone was located or where the ureterotomy was performed.
Using the wrong MS-DRG pathway for inpatient cases — when an open ureterolithotomy (O.R. procedure) is performed inpatient, the case groups to the surgical DRG triplet (659/660/661), NOT to the medical urinary stone DRGs (693/694). Failure to code the ICD-10-PCS procedure correctly will cause the case to group to the lower-paying medical DRG, resulting in significant under-reimbursement.

📚 References

^[1] AMA CPT Codebook 2025 — Surgery, Urinary System, Incision/Biopsy Procedures on the Ureter: Ureterolithotomy (50610-50630) ^[2] CMS Medicare Physician Fee Schedule 2025 (MPFS) — Addendum B, National RVU and Payment Files ^[3] CMS NCCI Policy Manual for Medicare Services FY2025, Chapter 8 — Surgery: Urinary System ^[4] AUA Core Curriculum — Urolithiasis: Surgical Management (Upper Urinary Tract Stones), American Urological Association 2024 ^[5] CMS ICD-10-PCS Official Guidelines for Coding and Reporting FY2025 — Root Operation Extirpation (C), Body System: Urinary System ^[6] CMS MS-DRG v42.0 Definitions Manual FY2025 — MDC 11, DRGs 659-661 (Kidney and Ureter Procedures for Non-Neoplasm) and DRGs 693-694 (Urinary Stones) ^[7] ICD-10-CM Official Guidelines for Coding and Reporting FY2025 — Chapter 14: Diseases of the Genitourinary System (N00-N99) ^[8] AAPC Codify — CPT 50610 Code Details, Bundling Edits, Forum Guidance (2025) ^[9] CMS IPPS FY2025 Final Rule — MS-DRG Relative Weights and Geometric Mean Length of Stay Tables ^[10] Smith & Tanagho’s General Urology, 19th Ed. — Chapter on Urinary Stone Disease: Surgical Management ^[11] Türk C et al. — EAU Guidelines on Urolithiasis 2024: Surgical Management of Upper Tract Stones

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