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ICD-10 Code N18.3: Chronic kidney disease, stage 3 (moderate)

N18.3 is an ICD-10 diagnosis entry used to group records related to Chronic kidney disease, stage 3 (moderate). You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the genitourinary system (N00-N99).

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the genitourinary system (N00-N99).

đź“‹Clinical overview

This ICD-10 code is commonly used when documentation describes chronic kidney disease or long-term loss of kidney function. The most accurate code depends on the documented CKD stage, whether end-stage kidney disease is present, and how clearly the record links kidney status to the active problem list.

When is it used?

  • May be used when a clinician documents chronic kidney disease, stage 3 (moderate) in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

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.
  • This entry may represent a broader category rather than the most specific billable code.

đź©şClinical context

When commonly used
  • Primary care, nephrology, inpatient, and chronic-disease documentation where reduced kidney function is part of ongoing management.
  • Risk-adjustment, utilization-review, and care-continuity workflows where CKD stage affects medication review, monitoring, and longitudinal care planning.
Common workup
  • Common related testing on this page includes Serum creatinine, Estimated glomerular filtration rate (eGFR), Urine albumin creatinine ratio.
  • Related procedures or service context already linked on this page include Hemodialysis, Peritoneal dialysis, Dialysis access procedure.
Common management context
  • CKD follow-up often includes kidney-function laboratory review, urine testing, blood-pressure management, medication reconciliation, and monitoring for disease progression.
  • Documentation usually becomes more specific when the chart identifies CKD stage, dialysis status, transplant history, proteinuria, anemia, or mineral and bone complications.
  • Specialist context already linked on this page includes Nephrologist, General Physician.

🔍Key distinctions

Important notes
  • ICD-10 CKD coding is stage-sensitive, so documentation that clearly states stage 1 through stage 5 or end-stage renal disease usually determines the final code choice.
  • CKD may coexist with diabetes, hypertension, anemia, or other chronic conditions, but separate linked diagnoses may still require their own more specific codes.
  • Stage 3 CKD is often split further in current documentation and coding workflows, so charted substage detail may affect code specificity.
Related codes to consider
N18.30Chronic kidney disease, stage 3 unspecified
Related chronic-kidney-disease ICD-10 code; documentation often becomes more specific when the chart identifies CKD stage, end-stage disease, or associated kidney-status detail.
N18.31Chronic kidney disease, stage 3a
Related chronic-kidney-disease ICD-10 code; documentation often becomes more specific when the chart identifies CKD stage, end-stage disease, or associated kidney-status detail.
N18.32Chronic kidney disease, stage 3b
Related chronic-kidney-disease ICD-10 code; documentation often becomes more specific when the chart identifies CKD stage, end-stage disease, or associated kidney-status detail.

Code hierarchy

chapter
14Diseases of the genitourinary system (N00-N99)
block
N17-N19Acute kidney failure and chronic kidney disease
category
N18Chronic kidney disease (CKD)
currentN18

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

NephrologistGeneral Physician

Related tests

Serum creatinine
Commonly reviewed in chronic kidney disease assessment.
Estimated glomerular filtration rate (eGFR)
Often used to assess kidney function stage and trend.
Urine albumin creatinine ratio
May help review protein leakage and kidney involvement.

Related procedures

Hemodialysis
May appear in advanced chronic kidney disease care pathways.
Peritoneal dialysis
May appear in advanced chronic kidney disease care pathways.
Dialysis access procedure
May be part of treatment planning when renal replacement therapy is needed.

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
N18.3
Replacement codes
N18.30 — Chronic kidney disease, stage 3 unspecifiedN18.31 — Chronic kidney disease, stage 3aN18.32 — Chronic kidney disease, stage 3b

Common synonyms

Chronic kidney disease, stage 3 (moderate)Chronic kidney disease, stage 3Chronic kidney disease, stage 3 moderate

Frequently asked questions

Code details

CodeN18.3
SystemICD10
Display nameChronic kidney disease, stage 3 (moderate)
ChapterDiseases of the genitourinary system (N00-N99)
BlockAcute kidney failure and chronic kidney disease

Flags

BillableNo
Valid clinical useNo

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

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.