Small kidney, unspecified

This code signifies a kidney that is abnormally reduced in size without a specified underlying cause. It indicates an anatomical finding rather than a specific disease process, often identified incidentally during imaging studies.

Apply this code when documentation clearly states "small kidney" or "renal hypoplasia" without further elaboration on the etiology. This is appropriate when the physician has not determined or documented the specific reason for the kidney's diminished size.

• Avoid using this code if a more specific cause for the small kidney (e.g., chronic kidney disease, renal artery stenosis) is documented.
• Always query the provider for clarification if the cause of the small kidney is suspected but not explicitly stated.
• Sequence this code as a secondary diagnosis when the primary reason for the encounter is related to the small kidney's effects or investigation.