Chronic gout due to renal impairment, unsp site, with tophus

This code signifies a persistent form of gout that has developed as a direct consequence of impaired kidney function. The presence of tophi, which are deposits of uric acid crystals, indicates a more advanced or severe manifestation of this metabolic disorder. The "unspecified site" component means the tophi are present but their specific anatomical location is not documented.

Apply this code when documentation clearly links chronic gout to renal impairment and explicitly mentions the presence of tophi, without specifying the affected joint or body part. This diagnosis is typically supported by laboratory findings of elevated serum uric acid, evidence of chronic kidney disease, and physical examination or imaging confirming tophaceous deposits.

• Ensure documentation explicitly states "chronic gout due to renal impairment" and "with tophus (tophi)."
• Do not use this code if the site of the tophus is specified; instead, use a more specific M1A.3- subcategory.
• Always code the underlying chronic kidney disease (CKD) separately, as it is the causal factor for the gout.