Idiopathic chronic gout, unspecified site, without tophus

This code signifies a persistent form of gout where the underlying cause is unknown (idiopathic), affecting an unspecified joint or location, and without the presence of visible or palpable urate crystal deposits (tophi). It indicates a long-standing inflammatory arthritis due to uric acid accumulation, but without the characteristic nodular formations.

Apply this code when documentation clearly states "idiopathic chronic gout" and explicitly denies the presence of tophi. This is appropriate when the specific joint involved is not documented or is generalized. Support for this code includes physician notes detailing chronic gout symptoms, elevated uric acid levels, and a lack of tophi on physical examination or imaging.

• Do not use this code if the specific site of chronic gout is documented; instead, use a more specific M1A.0- code.
• Ensure documentation explicitly states "without tophus" or "no tophi" to avoid miscoding with tophaceous gout.
• If the cause of chronic gout is known (e.g., drug-induced, lead poisoning), select a code from category M1A.2- or M1A.3-.