What does ICD-10 code N27 mean?

ICD-10 code N27 is the standardized code used for small kidney of unknown cause in medical records and coding systems.

When is ICD-10 code N27 used?

Doctors, hospitals, and insurers may use ICD-10 code N27 when recording small kidney of unknown cause in a standardized format. This entry may also act as a broader category that points toward more specific child codes.

Does ICD-10 code N27 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10

ICD-10 Code N27: Small kidney of unknown cause

Name: ICD-10 Code N27: Small kidney of unknown cause
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:26:36.498Z

N27 is an ICD-10 diagnosis entry used to group records related to Small kidney of unknown cause. 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).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

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).

When is it used?

May be used when a clinician documents small kidney of unknown cause 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.

Code hierarchy

chapter

14Diseases of the genitourinary system (N00-N99)

block

N25-N29Other disorders of kidney and ureter

currentN25-N29

Official coding notes

Includes

oligonephronia

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

UrologistGynecologist

Sibling codes

N25Disorders resulting from impaired renal tubular function N26Unspecified contracted kidney N28Other disorders of kidney and ureter, not elsewhere classified N29Other disorders of kidney and ureter in diseases classified elsewherebillable

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

N27

Replacement codes

N27.0 — Small kidney, unilateralN27.1 — Small kidney, bilateralN27.9 — Small kidney, unspecified

Common synonyms

Small kidney of unknown cause

Frequently asked questions

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.