Non-Billable / Non-Specific Code
ICD-10-CM M18 is the diagnosis code for Osteoarthritis of first carpometacarpal joint. This code falls under the section "Osteoarthritis" within Chapter 13 — Diseases of the musculoskeletal system and connective tissue (M00-M99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.
Understanding where M18 sits in the ICD-10-CM classification helps ensure proper coding:
No, M18 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
M18 is the ICD-10-CM diagnosis code for "Osteoarthritis of first carpometacarpal joint". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
M18 is located in Section M15-M19 — "Osteoarthritis" within Chapter 13 of the ICD-10-CM Tabular List.
M18 has 7 sub-code(s) that provide more specific detail: M18.0, M18.1, M18.2, M18.3, M18.4 and more.
Use M18 when the patients documented diagnosis matches "Osteoarthritis of first carpometacarpal joint" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Osteoarthritis of first carpometacarpal joint is M18.
No, M18 is non-billable. Use a more specific sub-code for primary diagnosis billing.
M18 is in Chapter 13 of the ICD-10-CM Tabular List.
Yes, M18 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.