M18.50 is the authoritative medical code for Other unilateral secondary osteoarthritis of first carpometacarpal joint, unspecified hand. This classification is used in medical billing and clinical recording to specify the clinical criteria for other unilateral secondary osteoarthritis of first carpometacarpal joint, unspecified hand (ICD-10-CM M18.50), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Official Registry Overview & Definition
Other unilateral secondary osteoarthritis of first carpometacarpal joint, unspecified hand is a billable ICD-10-CM diagnosis code M18.50. Excludes2 (not included here): osteoarthritis of spine M47.-.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for M18.50 in the official ICD-10-CM tabular list.
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- osteoarthritis of spine M47.-
Frequently Asked Questions (FAQ) & Clinical Guidance
Can M18.50 be reported alongside related conditions?
Per Excludes2 instructions, M18.50 and the following may both be reported when both are present: osteoarthritis of spine (M47.-).
Codes in This Family (16)
Official ICD-10-CM classifications in the same code family as M18.50, with their registry titles.
- M18 — Osteoarthritis of first carpometacarpal joint
- M18.0 — Bilateral primary osteoarthritis of first carpometacarpal joints
- M18.1 — Unilateral primary osteoarthritis of first carpometacarpal joint
- M18.10 — Unilateral primary osteoarthritis of first carpometacarpal joint, unspecified hand
- M18.11 — Unilateral primary osteoarthritis of first carpometacarpal joint, right hand
- M18.12 — Unilateral primary osteoarthritis of first carpometacarpal joint, left hand
- M18.2 — Bilateral post-traumatic osteoarthritis of first carpometacarpal joints
- M18.3 — Unilateral post-traumatic osteoarthritis of first carpometacarpal joint
- M18.30 — Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, unspecified hand
- M18.31 — Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, right hand
- M18.32 — Unilateral post-traumatic osteoarthritis of first carpometacarpal joint, left hand
- M18.4 — Other bilateral secondary osteoarthritis of first carpometacarpal joints
- M18.5 — Other unilateral secondary osteoarthritis of first carpometacarpal joint
- M18.51 — Other unilateral secondary osteoarthritis of first carpometacarpal joint, right hand
- M18.52 — Other unilateral secondary osteoarthritis of first carpometacarpal joint, left hand
- M18.9 — Osteoarthritis of first carpometacarpal joint, unspecified
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures: