N27

Small kidney of unknown cause

FY2027Chapter 14: Diseases of the genitourinary system/N25–N29 Other disorders of kidney and ureter

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

N27 is a non-billable ICD-10-CM code category for small kidney of unknown cause. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are N27.0 Small kidney, unilateral; N27.1 Small kidney, bilateral and N27.9 Small kidney, unspecified. Its coding notes include 9 Excludes2 entries.

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (9 notes)
Inherited from N25–N29 Other disorders of kidney and ureter
  • disorders of kidney and ureter with urolithiasis (N20-N23)
Inherited from Chapter 14 Diseases of the genitourinary system
  • 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)

Includes

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

This code
  • oligonephronia

More specific codes under N27 3