M18.5 – Other unilateral secondary osteoarthritis of first carpometacarpal joint
ICD-10-CM 2027 diagnosis code · Osteoarthritis
- Code
M18.5(claims format:M185)- Description
- Other unilateral secondary osteoarthritis of first carpometacarpal joint
- Short description
- Oth unil secondary osteoarth of first carpometacarp joint
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
- Block
- M15-M19 Osteoarthritis
- Parent codes
- M18
Billable codes under M18.5
M18.5 is a header code and cannot be used on claims. Choose the most specific code:
- M18.50 – Other unilateral secondary osteoarthritis of first carpometacarpal joint, unspecified handBillable
- M18.51 – Other unilateral secondary osteoarthritis of first carpometacarpal joint, right handBillable
- M18.52 – Other unilateral secondary osteoarthritis of first carpometacarpal joint, left handBillable
Notes for M18.5
- Secondary osteoarthritis of first carpometacarpal joint NOS
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
Block M15-M19
- osteoarthritis of spine (M47.-)
Index terms for M18.5
Entries in the ICD-10-CM alphabetic index that lead to this code:
Related codes in M18
- M18.0 – Bilateral primary osteoarthritis of first carpometacarpal jointsBillable
- M18.1 – Unilateral primary osteoarthritis of first carpometacarpal jointHeader
- M18.2 – Bilateral post-traumatic osteoarthritis of first carpometacarpal jointsBillable
- M18.3 – Unilateral post-traumatic osteoarthritis of first carpometacarpal jointHeader
- M18.4 – Other bilateral secondary osteoarthritis of first carpometacarpal jointsBillable
- M18.9 – Osteoarthritis of first carpometacarpal joint, unspecifiedBillable
Frequently asked questions
What is ICD-10 code M18.5?
M18.5 is the ICD-10-CM code for other unilateral secondary osteoarthritis of first carpometacarpal joint, in the block M15-M19 (Osteoarthritis).
Is M18.5 a billable code?
No. M18.5 is a header code with more specific child codes; report one of the billable codes listed above.
What category does M18.5 belong to?
It belongs to category M18 – Osteoarthritis of first carpometacarpal joint.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.