C38.0
BillableMalignant neoplasm of heart
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C38.0 an HCC code?
Yes. C38.0 maps to Lung and Other Severe 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 C38.0
For C38.0 to 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 C38.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C38.0 is the ICD-10-CM diagnosis code for malignant neoplasm of heart. Cancer that originates in the heart tissue itself, which is extremely rare. C38.0 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of respiratory and intrathoracic organs (c30-c39).
Under the CMS-HCC V28 risk adjustment model, C38.0 maps to Lung and Other Severe Cancers (HCC 20) with a community, non-dual, aged base RAF weight of 0.000. Under the older CMS-HCC V24 model, C38.0 maps to Colorectal, Bladder, and Other Cancers (HCC 11) with a community, non-dual, aged base RAF weight of 0.306. 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.
Primary cardiac malignancies are very uncommon; verify that this is not a metastatic cancer to the heart. Because C38.0 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 C38.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Primary cardiac malignancies are very uncommon; verify that this is not a metastatic cancer to the heart
- •Distinguish from pericardial cancers (C38.4) and mediastinal cancers
Clinical Significance
Primary cardiac malignancies are extremely rare, with cardiac sarcomas (angiosarcoma most common) being the predominant type. Most cardiac tumors are metastatic rather than primary. These patients have very poor prognosis and require complex management including cardiac surgery, making accurate distinction between primary and secondary cardiac cancer essential.
Documentation Requirements
- ✓Pathology confirmation of primary cardiac malignancy (not metastatic)
- ✓Echocardiography, cardiac MRI, or CT confirming tumor location within the heart
- ✓Histological type (angiosarcoma, rhabdomyosarcoma, fibrosarcoma, lymphoma)
- ✓Assessment of hemodynamic impact and cardiac function
- ✓Documentation clearly distinguishing primary from metastatic cardiac disease
Excludes 1 — Do NOT code together
- malignant neoplasm of great vessels (C49.3)