N20-N23
Medium Complexity

Urolithiasis

Primary Specialty: Urology
Last Updated: 2025-09-10

ICD-10 Codes (7)

7 billable
0 category headers
N21
Billable
Calculus of lower urinary tract
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N21.0
Billable
Calculus in bladder
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N21.1
Billable
Calculus in urethra
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N21.8
Billable
Other lower urinary tract calculus
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N21.9
Billable
Calculus of lower urinary tract, unspecified
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N22
Billable
Calculus of urinary tract in diseases classified elsewhere
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N23
Billable
Unspecified renal colic
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Updates & Changes

FY 2026 Updates

Current Year

New Codes (2)

N18.30
Chronic kidney disease, stage 3a (GFR 45-59)
N18.31
Chronic kidney disease, stage 3b (GFR 30-44)

Revised Codes (1)

N18.6
End stage renal disease - updated to align with KDIGO guidelines

Deleted Codes(1)

N18.3
Chronic kidney disease, stage 3 (moderate) - replaced by more specific 3a/3b staging

Historical Changes

  • FY 2025: Routine maintenance updates with minor terminology clarifications
  • FY 2024: Enhanced specificity requirements for certain code ranges
  • FY 2023: Updated documentation guidelines for improved clarity

Upcoming Changes

  • Proposed updates pending review by Coordination and Maintenance Committee
  • Under consideration: Enhanced digital health integration codes

Implementation Guidance

  • Review all FY 2026 updates for N20-N23 codes before implementation
  • Always verify the most current codes in the ICD-10-CM manual
  • Ensure clinical documentation supports the selected diagnosis codes
  • +3 more guidance items...

Range Overview

high priority

The ICD-10 code range N20-N23 pertains to Urolithiasis, a medical condition characterized by the formation of stones in the urinary system. This range includes codes for kidney stones (N20), ureteral stones (N20.1), bladder stones (N21), and other lower urinary tract stones (N22). It also covers unspecified urinary calculus (N23). These codes are used to document diagnoses related to urinary stones in patient records, insurance claims, and public health statistics.

Key Usage Points:

  • N20.0 is used for calculus of kidney.
  • N20.1 is used for calculus of ureter.
  • N20.2 is used for calculus of kidney with calculus of ureter.
  • N21.0 is used for calculus in bladder.
  • N23 is used for unspecified renal colic.

Coding Guidelines

When to Use:

  • When a patient is diagnosed with kidney stones.
  • When a patient is diagnosed with ureteral stones.
  • When a patient is diagnosed with bladder stones.
  • When a patient is diagnosed with other lower urinary tract stones.
  • When a patient has unspecified urinary calculus.

When NOT to Use:

  • When a patient has gallstones (use K80-K81).
  • When a patient has salivary gland stones (use K11.5).
  • When a patient has pancreatic stones (use K86.1).
  • When a patient has stones in other organs.

Code Exclusions

Always verify exclusions in the ICD-10 manual to ensure accurate coding.

Documentation Requirements

Documentation for Urolithiasis should include a clear diagnosis, location of the stone(s), any complications, and the patient's symptoms. It should also include any relevant medical history, physical examination findings, and results from diagnostic tests.

Clinical Information:

  • Specific diagnosis
  • Location of the stone(s)
  • Any complications
  • Patient's symptoms
  • Relevant medical history

Supporting Evidence:

  • Physical examination findings
  • Results from diagnostic tests
  • Imaging reports
  • Laboratory test results
Good Documentation Example:

Patient diagnosed with calculus of kidney and ureter (N20.2) with severe pain. CT scan confirms presence of stones in both kidney and ureter.

Poor Documentation Example:

Patient has kidney stones.

Common Documentation Errors:

  • Not specifying the location of the stone(s)
  • Not including any complications
  • Not documenting the patient's symptoms
  • Not including supporting evidence

Range Statistics

4
Total Codes
7
Billable
Complexity:
Medium
Primary Use:Clinical Documentation
Chapter:14

Coding Complexity

Medium
Complexity Rating

The complexity rating for Urolithiasis codes is medium due to the need to accurately identify the location of the stone(s), any complications, and interpret supporting evidence. Coders must also distinguish between different types of urinary stones and understand the patient's symptoms.

Key Factors:
  • Determining the specific location of the stone(s)
  • Identifying any complications
  • Interpreting supporting evidence
  • Distinguishing between different types of urinary stones
  • Understanding the patient's symptoms

Specialty Focus

Urolithiasis codes are primarily used by urologists, but may also be used by primary care physicians, emergency medicine physicians, and nephrologists. They are used to diagnose and treat urinary stones.

Primary Specialties:
Urology
60%
Primary Care
20%
Emergency Medicine
10%
Nephrology
10%
Clinical Scenarios:
  • A patient presenting with severe flank pain diagnosed with kidney stones.
  • A patient with a history of bladder stones presenting with urinary symptoms.
  • A patient with known ureteral stones presenting with hematuria.
  • A patient with lower urinary tract symptoms found to have bladder stones on imaging.
  • A patient with unspecified renal colic.

Resources & References

Resources for Urolithiasis coding include the ICD-10 manual, official coding guidelines, and clinical references. Educational materials such as coding handbooks and online courses can also be helpful.

Official Guidelines:

  • ICD-10-CM Official Guidelines for Coding and Reporting
  • American Urological Association Guidelines
  • National Institute for Health and Care Excellence (NICE) Guidelines

Clinical References:

  • Urology textbooks
  • Clinical journal articles

Educational Materials:

  • ICD-10 coding handbooks
  • Online coding courses

Frequently Asked Questions

Can N20-N23 codes be used for stones in other organs?

No, the N20-N23 code range is specifically for urinary stones. Stones in other organs have their own specific codes.