Is M18 a billable code?
No. M18 is a header code that groups 13 more specific codes. Use one of the billable codes listed on this page instead.
ICD-10-CM FY2027 diagnosis code
M18: Osteoarthritis of first carpometacarpal joint
Header code: not billableValid for dates of service October 1, 2026 to September 30, 2027
M18 groups related diagnoses under osteoarthritis of first carpometacarpal joint. It cannot be used on a claim by itself. Choose the billable code below that matches the patient's record.
Billable codes under M18
- M18.0Bilateral primary osteoarthritis of first carpometacarpal joints
- 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
- M18.2Bilateral post-traumatic osteoarthritis of first carpometacarpal joints
- 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
- M18.4Other bilateral secondary osteoarthritis of first carpometacarpal joints
- 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
- M18.9Osteoarthritis of first carpometacarpal joint, unspecified
M18 questions
What does M18 mean?
M18 is the ICD-10-CM code for Osteoarthritis of first carpometacarpal joint. It is in chapter 13, Diseases of the musculoskeletal system and connective tissue (M00-M99).
Code titles come from the official ICD-10-CM files published by the CDC National Center for Health Statistics. Always check payer rules and the clinical record before billing.