ICD-10 C31
Non-Billable HeaderMalignant neoplasm of accessory sinuses
About ICD-10-CM C31
ICD-10-CM code C31 represents Malignant neoplasm of accessory sinuses. This is a non-billable header code in the Neoplasms chapter (block C31). The 2026 edition of ICD-10-CM C31 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Medicare LCD Coverage for C31
Local Coverage Determinations (LCDs) from CMS MACs that list C31 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing C31.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but C31 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with C31
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To C31
Other codes in section C30-C39 (Malignant neoplasms of respiratory and intrathoracic organs).
ICD-10 C31, Billing FAQ
Is ICD-10 code C31 billable? +
No, C31 is a non-billable header code. Use a more specific child code from block C31 when submitting claims.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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