Is M31 a billable ICD-10-CM code?

No. M31 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does M31 sit in the tabular list?

Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Systemic connective tissue disorders (M30-M36).

M31

M31 — Other necrotizing vasculopathies

Non-billable headerICD-10-CM

M31 is a non-billable header ICD-10-CM code for other necrotizing vasculopathies. It cannot be billed on its own: choose one of the more specific child codes below.

Other codes that can never be billed with M31

These codes carry an Excludes1 note pointing at M31. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading M31 alone.

L95Vasculitis limited to skin, not elsewhere classified
M30Polyarteritis nodosa and related conditions
M35.3Polymyalgia rheumatica
N08Glomerular disorders in diseases classified elsewhere
D69Purpura and other hemorrhagic conditions
D68.5Primary thrombophilia
I77.6Arteritis, unspecified
J99Respiratory disorders in diseases classified elsewhere

Risk adjustment

M31 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead M31

10 child codes. Green means billable.

Questions about M31

Is M31 a billable ICD-10-CM code?: No. M31 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does M31 sit in the tabular list?: Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Systemic connective tissue disorders (M30-M36).