2027 ICD-10-CM Diagnosis Code N27Small kidney of unknown cause

ICD-10-CM Codes›N00–N99›N25-N29›N27

ICD-10-CM N27
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N27 is a non-billable ICD-10-CM category code for small kidney of unknown cause, so it cannot be submitted on claims. Use a more specific code from this category instead, such as N27.0, N27.1, and N27.9.

Code Identity

ICD-10-CM Code
N27
Billable Status
No — Non-Billable Category
Code Describes
Small kidney of unknown cause
Short Description
Small kidney of unknown cause
Same as the full description in the CMS dataset.
Chapter
N25-N29
Other disorders of kidney and ureter

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN25-N29Other disorders of kidney and ureter
CategoryN27Small kidney of unknown cause
This CodeN27Small kidney of unknown cause

Specific Coding for Small kidney of unknown causeOverview

Non-specific codes like N27 require more characters. Use one of these billable codes instead:

  • Use N27.0 for Small kidney, unilateral

  • Use N27.1 for Small kidney, bilateral

  • Use N27.9 for Small kidney, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N27: its own notes plus those printed at block N25-N29 and Chapter 14. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

  • oligonephronia

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block N25-N29 Other disorders of kidney and ureter applies to 22 codes
  • disorders of kidney and ureter with urolithiasis (N20-N23)
From Chapter 14 (N00-N99) Diseases of the genitourinary system applies to 838 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name N27, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming N27: they are not reported together with it, unless the two conditions are unrelated.

  • N26 Unspecified contracted kidney
    small kidney of unknown cause (N27.-)

Patient EducationClinical

Kidney Diseases

You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N27Overview

What is the ICD-10 code for small kidney of unknown cause?

N27 is the ICD-10-CM category for small kidney of unknown cause, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is N27 (Small kidney of unknown cause) a billable code?

No. This is a category header that groups the codes for small kidney of unknown cause, and headers cannot be submitted on claims. Claims for small kidney of unknown cause need a more specific code from this category, such as N27.0, N27.1, and N27.9.