M18.5 Other unilateral secondary osteoarthritis of first carpometacarpal joint
The ICD-10-CM code for Other unilateral secondary osteoarthritis of first carpometacarpal joint is M18.5 (FY2026). It is a non-billable category code — select a more specific code below for claims.
Classification
- Section
- M15-M19: Osteoarthritis (M15-M19)
- Category M18
- 17 codes (13 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to M18.5:
- Osteoarthritis › secondary › hand joint › first carpometacarpal joint
Inclusion Terms
- Secondary osteoarthritis of first carpometacarpal joint NOS
Official Coding Guidelines
Osteoporosis without pathological fracture (M81)Category M81, Osteoporosis without current pathological fracture, is for use for patients with osteoporosis who do not currently have a pathologic fracture due to the osteoporosis, even if they have had a fracture in the past. For patients with a history of osteoporosis fractures, status code Z87.310, Personal history of (healed) osteoporosis fracture, should follow the code from M81.
Osteoporosis with current pathological fracture (M80)Category M80, Osteoporosis with current pathological fracture, is for patients who have a current pathologic fracture at the time of an encounter. The codes under M80 identify the site of the fracture. A code from category M80, not a traumatic fracture code, should be used for any patient with known osteoporosis who suffers a fracture, even if the patient had a minor fall or trauma, if that fall or trauma would not usually break a normal, healthy bone.
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026