C26.0
BillableMalignant neoplasm of intestinal tract, part unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C26.0 an HCC code?
Yes. C26.0 maps to Bladder, Colorectal, and Other Cancers under the CMS-HCC V28 risk adjustment model (and Colorectal, Bladder, and Other Cancers under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for C26.0
For C26.0to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed C26.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C26.0 is the ICD-10-CM diagnosis code for malignant neoplasm of intestinal tract, part unspecified. Cancer of the intestinal tract where the specific part of the intestines affected is not clearly identified. C26.0 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of digestive organs (c15-c26).
Under the CMS-HCC V28 risk adjustment model, C26.0 maps to Bladder, Colorectal, and Other Cancers (HCC 22) with a community, non-dual, aged base RAF weight of 0.363. Under the older CMS-HCC V24 model, C26.0 maps to Colorectal, Bladder, and Other Cancers (HCC 11) with a community, non-dual, aged base RAF weight of 0.307. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This code indicates insufficient specificity; attempt to determine if cancer is in small intestine, colon, or rectum. Because C26.0 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for C26.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code indicates insufficient specificity; attempt to determine if cancer is in small intestine, colon, or rectum
- •Review pathology reports and imaging studies to identify the precise intestinal location
Clinical Significance
This code represents malignant neoplasm of the intestinal tract when the specific segment (small intestine, colon, rectum) cannot be determined. This is a clinically significant gap in documentation because treatment protocols and prognosis differ dramatically between intestinal segments. It carries a lower HCC weight than pancreatic or lung cancers but still impacts risk adjustment.
Documentation Requirements
- ✓Pathology confirmation of intestinal malignancy
- ✓Documentation that specific intestinal segment cannot be identified
- ✓Evidence of provider query for anatomical specificity
- ✓Imaging and endoscopy reports reviewed for location detail
- ✓Treatment status and disease stage
Commonly Confused Codes
- •C18.9 — Malignant neoplasm of colon, unspecified: If the tumor is known to be colonic, use C18.9 instead
- •C17.9 — Malignant neoplasm of small intestine, unspecified: Use when small intestine origin is confirmed
- •C20 — Malignant neoplasm of rectum: Rectal cancers have distinct treatment protocols and should not default to C26.0
- •C26.9 — Ill-defined digestive system: C26.0 is specific to intestinal tract; C26.9 covers broader digestive system