ICD-10-CM Code N18.9 – Chronic kidney disease, unspecified

Code: N18.9 Type: ICD-10-CM (Diagnosis) Status: Active Effective: FY2016-2026

What does ICD-10-CM code N18.9 mean?

N18.9 represents Chronic kidney disease, unspecified. This genitourinary condition is classified under Chapter 14 (Diseases of the Genitourinary System) and is commonly encountered in both primary care and specialty settings. This condition is commonly abbreviated as CRF, Chronic renal failure in clinical documentation. Coders frequently reference this code as ckd icd 10, ckd stage 3 icd 10, ckd 3 icd 10, or ckd icd 10 code.

Code category and hierarchy

  • Chapter: 14 – Diseases of the Genitourinary System (N00-N99)
  • Category: N18
  • Code: N18.9 – Chronic kidney disease, unspecified

Guideline notes and coding considerations

Specificity Warning

N18.9 is an unspecified code. Query the provider for greater specificity when documentation suggests a more precise code is available. Using unspecified codes when specific codes exist may trigger audits.

  • Code First: any associated:; diabetic chronic kidney disease ( E08.22 , E09.22 , E10.22 , E11.22 , E13.22 ); hypertensive chronic kidney disease ( I12 .-, I13 .-)
  • Use Additional Code: code, if applicable, to identify:; associated cachexia ( E88.A ); kidney transplant status ( Z94.0 )

Learn the underlying rules in the ICD-10 Coding Guidelines, Specificity Requirements.

Documentation tips (what coders should confirm)

  • Verify the clinical documentation supports the use of N18.9
  • Query the provider for greater specificity if clinical details suggest a more precise code
  • Code first: any associated: | diabetic chronic kidney disease ( E08.22 , E09.22 , E10.22 , E11.22 , E13.22 ) | hypertensive chronic
  • Use additional code: code, if applicable, to identify: | associated cachexia ( E88.A ) | kidney transplant status ( Z94.0 )

When NOT to use N18.9

Do not assign N18.9 when the clinical scenario involves: when documentation provides enough detail for a more specific code. Review excludes notes and assign the most specific code supported by documentation.

Audit risk

N18.9 is an unspecified code. Payers and auditors may flag claims with unspecified codes when the medical record contains sufficient detail for a more precise diagnosis. Query the provider for specificity before submitting.

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Related ICD-10 codes

N10

Acute pyelonephritis

N12

Tubulo-interstitial nephritis, not specified as acute or chronic

N17.9

Acute kidney failure, unspecified

N20.0

Calculus of kidney

Frequently Asked Questions

The ICD-10-CM code for ckd is N18.9, which represents chronic kidney disease, unspecified. This code is also commonly referenced as ckd stage 3 icd 10, ckd 3 icd 10, ckd icd 10 code. Verify this code using the ICD Code Auditor to ensure guideline compliance.

Yes. N18.9 is an active ICD-10-CM diagnosis code used to classify chronic kidney disease, unspecified for clinical documentation, reporting, and medical billing purposes.

Use the ICD Code Auditor to check N18.9 against official ICD-10-CM coding guidelines. The tool validates by fiscal year and patient gender to identify potential conflicts.

N18.9 should be used only when clinical documentation does not provide enough detail for a more specific code. Always query the provider when documentation suggests greater specificity is available, as unspecified codes may trigger audits and impact risk adjustment.

Documentation should clearly describe the clinical condition represented by N18.9 (Chronic kidney disease, unspecified). Include relevant clinical findings, diagnostic test results, provider assessment, and the treatment plan. The diagnosis must be supported by the medical record and not based solely on lab results without clinical interpretation.

Sources

Reviewed by: Certified ICD-10 Coding & Risk Adjustment Specialist
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Validate N18.9 Against ICD 10 CM Coding Guidelines (FY2026)

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