ICD-10 C18
Non-Billable HeaderMalignant neoplasm of colon
About ICD-10-CM C18
ICD-10-CM code C18 represents Malignant neoplasm of colon. This is a non-billable header code in the Neoplasms chapter (block C18). The 2026 edition of ICD-10-CM C18 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.
Type 1 Excludes
Pure excludes, these codes can never be coded together with C18. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- malignant carcinoid tumors of the colon (C7A.02-)
Medicare LCD Coverage for C18
Local Coverage Determinations (LCDs) from CMS MACs that list C18 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 C18.
2 Cigna
CPT Codes Commonly Billed with C18
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 C18
Other codes in section C15-C26 (Malignant neoplasms of digestive organs).
ICD-10 C18, Billing FAQ
Is ICD-10 code C18 billable? +
No, C18 is a non-billable header code. Use a more specific child code from block C18 when submitting claims.
What codes are Type 1 Excludes for C18? +
Type 1 Excludes (never code together with C18): malignant carcinoid tumors of the colon (C7A.02-)
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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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