M1A.0421 Idiopathic chronic gout, left hand, with tophus (tophi)

Billable ICD-10-CM code, FY2026.

Built from M1A.042 with 7th character 1 (with tophus (tophi)).

Applies from M1A Chronic gout

Excludes1 (never code together)

• gout NOS (M10.-)

Excludes2 (not included here)

• acute gout (M10.-)

Use additional code

• code to identify:
• Autonomic neuropathy in diseases classified elsewhere (G99.0)
• Calculus of urinary tract in diseases classified elsewhere (N22)
• Cardiomyopathy in diseases classified elsewhere (I43)
• Disorders of external ear in diseases classified elsewhere (H61.1-, H62.8-)
• Disorders of iris and ciliary body in diseases classified elsewhere (H22)
• Glomerular disorders in diseases classified elsewhere (N08)

7th character note

• The appropriate 7th character is to be added to each code from category M1A

7th character required

• 0 — without tophus (tophi)
• 1 — with tophus (tophi)

Applies from M1A.0 Idiopathic chronic gout

Applicable to

• Chronic gouty bursitis
• Primary chronic gout

Code annotations containing back-references to M1A.0421

Back-references to M1A

• Type 1 Excludes: E72 Other disorders of amino-acid metabolism ("gout (M1A.-, M10.-)")
• Type 1 Excludes: E79 Disorders of purine and pyrimidine metabolism ("gout (M1A.-, M10.-)")
• Code First: G99.0 Autonomic neuropathy in diseases classified elsewhere ("gout (M1A.-, M10.-)")
• Code First: H22 Disorders of iris and ciliary body in diseases classified elsewhere ("gout (M1A.-, M10.-)")
• Type 2 Excludes: H61.1 Noninfective disorders of pinna ("gouty tophi of ear (M1A.-)")
• Code First: H62.8 Other disorders of external ear in diseases classified elsewhere ("gout (M1A.-, M10.-)")
• Type 2 Excludes: M10 Gout ("chronic gout (M1A.-)")
• Code First: N08 Glomerular disorders in diseases classified elsewhere ("gout (M1A.-, M10.-)")
• Code First: N22 Calculus of urinary tract in diseases classified elsewhere ("gout (M1A.-, M10.-)")

Nearby codes

• M1A.041 Idiopathic chronic gout, right hand
• M1A.0410 Idiopathic chronic gout, right hand, without tophus (tophi)
• M1A.0411 Idiopathic chronic gout, right hand, with tophus (tophi)
• M1A.042 Idiopathic chronic gout, left hand
• M1A.0420 Idiopathic chronic gout, left hand, without tophus (tophi)
• M1A.0421 Idiopathic chronic gout, left hand, with tophus (tophi) (this code)
• M1A.049 Idiopathic chronic gout, unspecified hand
• M1A.0490 Idiopathic chronic gout, unspecified hand, without tophus (tophi)
• M1A.0491 Idiopathic chronic gout, unspecified hand, with tophus (tophi)
• M1A.05 Idiopathic chronic gout, hip
• M1A.051 Idiopathic chronic gout, right hip