ICD10BillableValid for clinical use

ICD-10 Code N21.8: Other lower urinary tract calculus

N21.8 is a billable ICD-10 diagnosis code used to classify Other lower urinary tract calculus in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the genitourinary system (N00-N99).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the genitourinary system (N00-N99).

When is it used?

  • May be used when a clinician documents other lower urinary tract calculus in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
14Diseases of the genitourinary system (N00-N99)
block
N20-N23Urolithiasis
category
N21Calculus of lower urinary tract
currentN21

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

UrologistGynecologist

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
N21.8

Common synonyms

Other lower urinary tract calculus

Frequently asked questions

Code details

CodeN21.8
SystemICD10
Display nameOther lower urinary tract calculus
ChapterDiseases of the genitourinary system (N00-N99)
BlockUrolithiasis

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Calculus, calculi, calculousCalculus, calculi, calculousCalculus, calculi, calculousStone(s)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code N21.8 for Other lower urinary tract calculus | HealthAssure