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ICD-10-CM tabular list

C15-C26Malignant neoplasms of digestive organs

ICD-10-CM codes C15-C26 cover malignant neoplasms of digestive organs, within neoplasms. The block holds 69 codes across 12 categories, of which 60 are billable and 9 are header codes that cannot be submitted on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • Kaposi's sarcoma of gastrointestinal sites (C46.4)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • gastrointestinal stromal tumors (C49.A-)

Risk adjustment in C15-C26

0 codes in this block map to a CMS-HCC, which means the diagnosis carries a risk-adjustment payment when it is documented and coded. Under-coding here is money left on the table; over-coding here is what audits are for.

  • HCC 20 Lung and Other Severe Cancers
  • HCC 22 Bladder, Colorectal, and Other Cancers

What else to watch in C15-C26

  • 60 codes are named in Medicare coverage policies. An LCD or NCD lists them as supporting medical necessity, or explicitly as not supporting it. Which applies depends on the MAC for your state.

Categories in C15-C26

ICD-10-CMFY2026-Apr· effective April 1, 2026