Non-Billable / Non-Specific Code
ICD-10-CM C18 is the diagnosis code for Malignant neoplasm of colon. This code falls under the section "Malignant neoplasms of digestive 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.
The following conditions should never be coded at the same time as C18. They are mutually exclusive:
Understanding where C18 sits in the ICD-10-CM classification helps ensure proper coding:
No, C18 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
C18 is the ICD-10-CM diagnosis code for "Malignant neoplasm of colon". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
C18 is located in Section C15-C26 — "Malignant neoplasms of digestive organs" within Chapter 2 of the ICD-10-CM Tabular List.
C18 has 10 sub-code(s) that provide more specific detail: C18.0, C18.1, C18.2, C18.3, C18.4 and more.
Use C18 when the patients documented diagnosis matches "Malignant neoplasm of colon" 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 colon is C18.
No, C18 is non-billable. Use a more specific sub-code for primary diagnosis billing.
C18 is in Chapter 2 of the ICD-10-CM Tabular List.
Type 1 Excludes for C18 include: malignant carcinoid tumors of the colon (C7A.02-).
Yes, C18 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.