C7A.8
BillableOther malignant neuroendocrine tumors
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C7A.8 an HCC code?
Yes. C7A.8 maps to Lymphoma and Other Cancers under the CMS-HCC V28 risk adjustment model (and Breast, Prostate, and Other Cancers and Tumors 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 C7A.8
For C7A.8to 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 C7A.8 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C7A.8 is the ICD-10-CM diagnosis code for other malignant neuroendocrine tumors. A rare cancer arising from hormone-producing cells that does not fit into the standard carcinoid tumor categories. C7A.8 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neuroendocrine tumors (c7a).
Under the CMS-HCC V28 risk adjustment model, C7A.8 maps to Lymphoma and Other Cancers (HCC 21) with a community, non-dual, aged base RAF weight of 0.671. Under the older CMS-HCC V24 model, C7A.8 maps to Breast, Prostate, and Other Cancers and Tumors (HCC 12) with a community, non-dual, aged base RAF weight of 0.150. 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 is a residual category; thoroughly document the tumor type and site to justify use of this code over more specific options. Because C7A.8 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 C7A.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a residual category; thoroughly document the tumor type and site to justify use of this code over more specific options
- •Review pathology reports to confirm neuroendocrine origin and rule out other malignancies
Clinical Significance
Other malignant neuroendocrine tumors is a residual category for malignant neuroendocrine neoplasms that do not classify as carcinoid tumors or poorly differentiated neuroendocrine carcinomas. This includes entities such as paragangliomas with malignant behavior, mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN), and other rare neuroendocrine tumor types. These tumors require specialized pathologic evaluation and multidisciplinary oncologic management.
Documentation Requirements
- ✓Pathology report with immunohistochemistry confirming neuroendocrine differentiation
- ✓Specific tumor type classification (paraganglioma, MiNEN, etc.)
- ✓Documentation that the tumor does not meet criteria for carcinoid (C7A.0) or poorly differentiated neuroendocrine carcinoma (C7A.1)
- ✓Primary site of origin
- ✓Functional status (hormone-producing vs non-functional)
- ✓Staging and treatment plan
Commonly Confused Codes
- •C7A.0 series — Malignant carcinoid tumors: Use C7A.0 codes for confirmed carcinoid-type neuroendocrine tumors with specific site
- •C7A.1 — Malignant poorly differentiated neuroendocrine tumors: Use when pathology confirms poor differentiation/Grade 3
- •C7A.098 — Malignant carcinoid tumors of other sites: C7A.098 is for carcinoid histology at unusual sites; C7A.8 is for non-carcinoid neuroendocrine tumors
- •D44.7 — Neoplasm of uncertain behavior of aortic body and other paraganglia: Use for paragangliomas of uncertain behavior