50640

🩺 CPT Code 50640 Ureterolithotomy, Calculus Removal

Quick Reference

Descriptor: Ureterolithotomy, calculus removal; lower one-third of ureter ¹
Global Period: 90 days ²
Assistant Surgeon: Payable with modifiers -80, -81, -82, -AS ³
wRVU: 13.66 | Total RVU: 23.46 (Non-Facility) ⁴
NCCI Status: Bundles diagnostic cystoscopy 52000; modifier indicator “1” for distinct procedures ⁵
Approach: Open Surgical (Incision)

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📋 Code Description & Clinical Context

CPT 50640 describes an open surgical procedure to remove a calculus (stone) from the lower one-third of the ureter ¹. This procedure involves making an incision (typically abdominal, suprapubic, or lumbar) to access the distal ureter, opening the ureter (ureterotomy), removing the stone, and closing the ureter. The descriptor explicitly includes cystoscopy performed during the same session ⁶.

Key Clinical Indications:

• Large impacted ureteral calculi in the distal ureter not amenable to ureteroscopy or ESWL
• Failed minimally invasive attempts (ureteroscopy, shock wave lithotripsy)
• Lower ureteral stones causing severe obstruction, infection, or renal compromise
• Anatomical anomalies preventing endoscopic access to the distal ureter
• Concurrent open pelvic surgery requiring ureteral stone removal

!NOTE Anatomical Specificity

This code is specific to the lower one-third of the ureter. Stones located in the upper one-third require 50620, and stones in the middle one-third require 50630 ⁷. Accurate anatomical documentation is critical for correct code selection.

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🌲 Code Hierarchy / Tree

Surgery (10000-69990)
└─ Urinary System (50000-55999)
   └─ Ureter (50500-50999)
      └─ Incision
         ├─ 50610 Ureterolithotomy, calculus removal; lower one-third of ureter
         ├─ 50620 Ureterolithotomy, calculus removal; upper one-third of ureter
         ├─ 50630 Ureterolithotomy, calculus removal; middle one-third of ureter
         └─ 50640 Ureterolithotomy, calculus removal; lower one-third of ureter ← THIS CODE

Parent Category: Incision Procedures on the Ureter ⁸
Laparoscopic Counterpart: 50548 (Laparoscopic ureterolithotomy) - Do not report both for same stone/session ⁹
Endoscopic Counterpart: 52356 (Cystourethroscopy with ureteroscopy and lithotripsy) ⁹

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💰 Reimbursement & Valuation

Component	Facility	Non-Facility	Notes
Work RVU	13.66	13.66	Physician effort component 4
Practice Expense RVU	6.50	7.85	Overhead/equipment (higher in office) 4
Malpractice RVU	1.95	1.95	Liability component 4
Total RVU	22.11	23.46	Base for payment calculation
Global Period	90 days	90 days	Major surgery; includes 1 pre-op + surgery day + 90 post-op days 210

Assistant Surgeon Payable: Yes

• Report with modifiers: -80 (Assistant Surgeon), -81 (Minimum Assistant), -82 (Assistant when resident unavailable), or -AS (PA/NP/CNS assistant) ³
• Medicare Status Indicator: “1” (Payment permitted for assistant)
• Reimbursement typically 16-25% of primary surgeon fee depending on payer policy

Medicare Payment Estimate: National average ~$850-$950 (Physician Fee), Facility fees separate ¹¹

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🚫 Includes / Excludes & NCCI Guidance

✅ Includes

• Open incision to access the lower ureter
• Ureterotomy (incision into the ureter)
• Removal of calculus (stone)
• Repair of ureteral incision
• Cystoscopy performed during the same operative session (bundled) ⁵
• Placement of ureteral stent (if performed, often bundled or separate depending on payer; check 50945)
• Intraoperative imaging (fluoroscopy) typically bundled unless extensive

❌ Excludes / Bundled Per NCCI

• Diagnostic cystoscopy 52000 (explicitly included in descriptor) ⁵
• Ureteroscopy 52351/52356 on the same ureter for the same stone (mutually exclusive approaches) ¹²
• ESWL 50590 on the same stone/session
• Open procedures for upper/middle ureter stones (use 50620 or 50630)
• Laparoscopic ureterolithotomy 50548 (different approach)

NCCI Edit Critical Note

Diagnostic cystoscopy 52000 is bundled into 50640 with a modifier indicator of “0” ¹³. It cannot be billed separately under any circumstances during the same session. However, if a distinct procedure (e.g., bladder tumor resection) is performed, modifier -59 may be applicable if the edit allows (Indicator “1”) ⁵.

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🏥 MS-DRG Assignment (Inpatient Facility)

If performed in an inpatient setting (rare for uncomplicated stones, common for complex/infected cases):

Scenario	MS-DRG	Description
Primary procedure: Kidney & Urinary Tract Procedures for Non-Malignancy with MCC	689	Highest severity/complexity 14
Primary procedure: Kidney & Urinary Tract Procedures for Non-Malignancy with CC	690	Moderate complexity 14
Primary procedure: Kidney & Urinary Tract Procedures for Non-Malignancy without CC/MCC	691	Baseline complexity 14

Admission must meet severity criteria. Uncomplicated stone removal is typically outpatient/ASC ¹⁵.

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🏷️ Common ICD-10-CM Diagnosis Codes

Primary Diagnosis Options

ICD-10-CM Code	Description	HCC Status*
N20.0	Calculus of kidney	❌ Not HCC
N20.1	Calculus of ureter	❌ Not HCC
N20.2	Calculus of kidney with calculus of ureter	❌ Not HCC
N20.9	Urinary calculus, unspecified	❌ Not HCC
N13.2	Hydronephrosis with renal and ureteral calculous obstruction	❌ Not HCC
N13.4	Hydroureter	❌ Not HCC
N10	Acute tubulo-interstitial nephritis (if infection present)	❌ Not HCC

• HCC Status: Hierarchical Condition Category mapping for Medicare Advantage risk adjustment. Urinary calculus codes (N20.x, N13.x) are generally not HCCs in current CMS-HCC models ^{16 17}. They are considered acute/episodic. Chronic Kidney Disease (CKD) codes (e.g., N18.3-, N18.4) are HCCs and should be reported if documented.

Supporting/Comorbid Codes (Document When Applicable)

• N18.30 Chronic kidney disease, stage 3 unspecified (HCC applicable)
• N18.4 Chronic kidney disease, stage 4 (HCC applicable)
• N18.5 Chronic kidney disease, stage 5 (HCC applicable)
• Z87.440 Personal history of urinary (tract) calculi
• R39.15 Urinary retention (if applicable)

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✏️ Modifiers Guidance

Modifier	Use Case for 50640	Payable?
-50	Bilateral Procedure: stones removed from lower ureter on both left and right sides	✅ Append to 50640 (or report LT/RT depending on payer)
-51	Multiple Procedures: when performed with other distinct procedures (e.g., nephrolithotomy)	✅ Subject to multiple procedure reduction
-59	Distinct Procedural Service: if cystoscopy involves distinct work (e.g., bladder biopsy) not bundled	⚠️ Verify NCCI edit indicator first
-80 / -81 / -82 / -AS	Assistant Surgeon services	✅ Payable per Medicare policy 3
-22	Increased Procedural Services: stone exceptionally large, impacted, or anatomy difficult	✅ If documentation supports & NCCI allows
-53	Discontinued Procedure: terminated due to patient risk (e.g., inability to locate stone)	✅ With operative note detail
-LT / -RT	Left Side / Right Side: Specify laterality if not using -50	✅ Required for clarity

Modifier -50 Usage

The ureters are paired organs. If stones are removed from the lower third of both ureters during the same session, report 50640--50 (or 50640--LT and 50640--RT). Do not report twice without modifier -50 unless payer specifies ¹⁸.

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📝 Coding Examples

✅ Example 1: Standalone Open Ureterolithotomy

Scenario: 55 y/o M with large impacted stone in distal left ureter. Failed ESWL. Surgeon performs open lower abdominal incision, isolates lower ureter, performs ureterotomy, removes 1.5cm stone, places stent, closes ureter. Cystoscopy performed to place stent.
Report:

• 50640--LT (Ureterolithotomy, lower ureter)
• N20.1 (Calculus of ureter)
• N13.2 (Hydronephrosis with obstruction)
  Rationale: Procedure matches descriptor. Cystoscopy is bundled ¹⁹.

❌ Example 2: Billing Cystoscopy Separately (Incorrect)

Scenario: Same as Example 1. Surgeon bills 50640 and 52000 (Cystoscopy).
Report: 50640 + 52000
Rationale: Incorrect. 52000 is explicitly included in the descriptor of 50640 and bundled per NCCI with modifier indicator “0” ⁵.

⚠️ Example 3: Bilateral Procedure

Scenario: Patient has symptomatic stones in lower third of both left and right ureters. Surgeon performs open ureterolithotomy on both sides during same anesthesia.
Report:

• 50640-50 (Bilateral procedure)
• N20.2 (Calculus of kidney with calculus of ureter) or N20.1
  Rationale: Ureters are paired. Modifier -50 indicates bilateral performance ¹⁸.

✅ Example 4: Assistant Surgeon Participation

Scenario: Complex reoperative pelvic surgery. Assistant surgeon provides exposure, retraction, and suturing assistance.
Report:

• Primary: 50640--LT
• Assistant: 50640-80--LT
• Diagnosis: N20.1
  Rationale: Assistant surgeon services are payable for 50640; document assistant’s specific contributions ³.

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🔍 Documentation Essentials for Support

To support 50640 and mitigate audit risk, operative documentation should include:

1. Approach: Explicitly state “open” approach (abdominal, suprapubic, or lumbar incision).
2. Location: Specify lower one-third of the ureter. (Critical for code selection vs 50620/50630).
3. Procedure: Describe ureterotomy, stone removal, and closure.
4. Cystoscopy: Mention cystoscopy was performed (do not bill separately, but document it was done as part of the procedure).
5. Stone Details: Size, number, and location of calculi removed.
6. Stent Placement: Document if internal stent was placed (often bundled, but supports medical necessity).
7. Laterality: Clearly indicate Left, Right, or Bilateral.

Anatomical Precision

Ensure the operative note distinguishes between upper, middle, and lower ureter. Coding auditors will verify stone location against the code selected. If the stone migrated or was found in the middle third, report 50630 instead.

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⚠️ Common Pitfalls & Audit Risks

Pitfall	Consequence	Prevention
Reporting 52000 with 50640	Claim denial (Bundled)	Remember cystoscopy is included in descriptor 5
Using 50640 for laparoscopic approach	Incorrect coding (Upcoding/Downcoding)	Use 50548 for laparoscopic ureterolithotomy 9
Using 50640 for upper/middle ureter stone	Incorrect coding	Use 50620 (upper) or 50630 (middle) based on anatomy 8
Omitting Modifier -50 for bilateral cases	Underpayment	Append -50 or -LT/-RT modifiers as per payer policy 18
Failing to document CKD status	Lost HCC Risk Adjustment	Document Chronic Kidney Disease stage if applicable (e.g., N18.30) 16

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🔗 Related Codes & Crosswalks

Code Type	Code	Relationship to 50640
CPT®	50620	Ureterolithotomy, upper one-third of ureter
CPT®	50630	Ureterolithotomy, middle one-third of ureter
CPT®	50548	Laparoscopic ureterolithotomy (different approach)
CPT®	52356	Ureteroscopy with lithotripsy (endoscopic approach)
CPT®	50590	Extracorporeal shock wave lithotripsy (non-invasive)
CPT®	50945	Ureteroscopy with stent insertion (if stent only)
ICD-10-PCS	0TCB0ZZ	Extirpation of Matter from Ureter, Open Approach (inpatient procedure coding)
HCPCS	None directly	No specific HCPCS Level II code crosswalk

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¹ AMA CPT 2024 Professional Edition
² CMS Global Surgery Factsheet
³ Medicare Claims Processing Manual Ch. 12
⁴ CMS Medicare Physician Fee Schedule 2024
⁵ CMS NCCI Policy Manual 2024
⁶ AUA Guidelines on Surgical Management of Stones
⁷ NIH VSAC CPT Hierarchy
⁸ NIH VSAC CPT Hierarchy
⁹ AUA Ureteroscopy Guidelines
¹⁰ Noridian Medicare Local Coverage Determinations
¹¹ Payer Price Fee Schedule 2026
¹² AHA Coding Clinic for ICD-10-CM/PCS
¹³ AAPC NCCI Edit Resources
¹⁴ CMS MS-DRG Manual v41.0
¹⁵ CMS Two-Midnight Rule Guidance
¹⁶ CMS-HCC Model V28 Documentation
¹⁷ Find-A-Code HCC Mapping Tool
¹⁸ Coding Mastery Modifier Guidelines
¹⁹ AAPC Coding Ureterolithotomy Procedures