M18 — Osteoarthritis of first carpometacarpal joint
Is M18 billable?
No — M18 is a non-billable header code. M18 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 13 billable codes beneath M18.
Billable codes under this header
- M18.0Bilateral primary osteoarthritis of first carpometacarpal joints
- M18.2Bilateral post-traumatic osteoarthritis of first carpometacarpal joints
- M18.4Other bilateral secondary osteoarthritis of first carpometacarpal joints
- M18.9Osteoarthritis of first carpometacarpal joint, unspecified
- M18.10Unilateral primary osteoarthritis of first carpometacarpal joint, unspecified hand
- M18.11Unilateral primary osteoarthritis of first carpometacarpal joint, right hand
- M18.12Unilateral primary osteoarthritis of first carpometacarpal joint, left hand
- M18.30Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand
- M18.31Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, right hand
- M18.32Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, left hand
- M18.50Other unilateral secondary osteoarthritis of first carpometacarpal joint, unspecified hand
- M18.51Other unilateral secondary osteoarthritis of first carpometacarpal joint, right hand
- M18.52Other unilateral secondary osteoarthritis of first carpometacarpal joint, left hand
M18 at a glance
| Code | M18 |
|---|---|
| Description | Osteoarthritis of first carpometacarpal joint |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes2 — not included here — inherited from Chapter 13
The conditions below are not part of M18, but a patient may have both at the same time. When documentation supports it, M18 and the excluded code may both be reported.
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Excludes2 — not included here — inherited from M15-M19
The conditions below are not part of M18, but a patient may have both at the same time. When documentation supports it, M18 and the excluded code may both be reported.
- osteoarthritis of spine (M47.-)
What codes fall under M18? (7)
- M18.0Bilateral primary osteoarthritis of first carpometacarpal joints
- M18.1Unilateral primary osteoarthritis of first carpometacarpal jointnot billable
- M18.2Bilateral post-traumatic osteoarthritis of first carpometacarpal joints
- M18.3Unilateral post-traumatic osteoarthritis of first carpometacarpal jointnot billable
- M18.4Other bilateral secondary osteoarthritis of first carpometacarpal joints
- M18.5Other unilateral secondary osteoarthritis of first carpometacarpal jointnot billable
- M18.9Osteoarthritis of first carpometacarpal joint, unspecified
How long has M18 existed?
M18 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.