M1AChronic gout

M1A is the ICD-10-CM diagnosis code for chronic gout. It belongs to block M05-M14 (inflammatory polyarthropathies) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 6 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: M1A.0 (gout), M1A.1 (gout), M1A.2 (gout), M1A.3 (due to renal impairment), M1A.4 (gout) and M1A.9 (unspecified).

Don't report M1A together with the conditions in its Excludes1 note: gout NOS (M10.-).

The conditions in its Excludes2 note aren't part of M1A, but may be coded alongside it if the patient has both: acute gout (M10.-).

Use an additional 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) and 1 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.