Is M18.1 a billable ICD-10-CM code?

No. M18.1 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does M18.1 sit in the tabular list?

Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Osteoarthritis (M15-M19).

M18.1

M18.1 — Unilateral primary osteoarthritis of first carpometacarpal joint

Non-billable headerICD-10-CM

M18.1 is a non-billable header ICD-10-CM code for unilateral primary osteoarthritis of first carpometacarpal joint. It cannot be billed on its own: choose one of the more specific child codes below.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Primary osteoarthritis of first carpometacarpal joint NOS

Risk adjustment

M18.1 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 M18.1

3 child codes. Green means billable.

Related codes at this level

Codes that share M18. If M18.1 is not quite right, the correct code is usually one of these.

Questions about M18.1

Is M18.1 a billable ICD-10-CM code?: No. M18.1 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does M18.1 sit in the tabular list?: Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Osteoarthritis (M15-M19).