Non-Billable / Non-Specific Code
ICD-10-CM C31 is the diagnosis code for Malignant neoplasm of accessory sinuses. This code falls under the section "Malignant neoplasms of respiratory and intrathoracic organs" within Chapter 2 — Neoplasms (C00-D49). 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 C31 sits in the ICD-10-CM classification helps ensure proper coding:
No, C31 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
C31 is the ICD-10-CM diagnosis code for "Malignant neoplasm of accessory sinuses". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
C31 is located in Section C30-C39 — "Malignant neoplasms of respiratory and intrathoracic organs" within Chapter 2 of the ICD-10-CM Tabular List.
C31 has 6 sub-code(s) that provide more specific detail: C31.0, C31.1, C31.2, C31.3, C31.8 and more.
Use C31 when the patients documented diagnosis matches "Malignant neoplasm of accessory sinuses" 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 Malignant neoplasm of accessory sinuses is C31.
No, C31 is non-billable. Use a more specific sub-code for primary diagnosis billing.
C31 is in Chapter 2 of the ICD-10-CM Tabular List.
Yes, C31 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.