M18.1
Unilateral primary osteoarthritis of first carpometacarpal joint
M18.1 is a non-billable ICD-10-CM code header for unilateral primary osteoarthritis of first carpometacarpal joint. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are M18.10 Unilateral primary osteoarthritis of first carpometacarpal joint, unspecified hand; M18.11 Unilateral primary osteoarthritis of first carpometacarpal joint, right hand and M18.12 Unilateral primary osteoarthritis of first carpometacarpal joint, left hand. Its coding notes include 11 Excludes2 entries.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (11 notes)
- 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)
Inclusion terms
Conditions classified to this code.
- Primary osteoarthritis of first carpometacarpal joint NOS
Notes
Also from chapter/block level (1 note)
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 1 entry