C70.1
BillableMalignant neoplasm of spinal meninges
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C70.1 an HCC code?
Yes. C70.1 maps to Lung and Other Severe Cancers under the CMS-HCC V28 risk adjustment model (and Lymphoma 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 C70.1
For C70.1 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 C70.1 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C70.1 is the ICD-10-CM diagnosis code for malignant neoplasm of spinal meninges. Cancer that starts in the protective membrane surrounding the spinal cord. This is a malignant tumor of the meninges, which are the layers of tissue that cover and protect the spinal cord. C70.1 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of eye, brain and other parts of central nervous system (c69-c72).
Under the CMS-HCC V28 risk adjustment model, C70.1 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, C70.1 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. 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.
Ensure documentation specifies that the neoplasm is in the spinal meninges, not the brain meninges (C70.0). Because C70.1 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 C70.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure documentation specifies that the neoplasm is in the spinal meninges, not the brain meninges (C70.0)
- •Verify histological type and grade when available, as this affects treatment planning and prognosis
Clinical Significance
Malignant neoplasm of the spinal meninges is rare and represents an aggressive cancer of the protective membrane surrounding the spinal cord. These tumors can cause spinal cord compression, paralysis, and severe neurological deficits. They require neurosurgical intervention and often adjuvant radiation therapy, driving high resource utilization.
Documentation Requirements
- ✓Pathology confirming malignancy (World Health Organization Grade III for meningioma or other malignant histological type)
- ✓Documentation explicitly identifying spinal meninges as the primary site
- ✓MRI spine documenting tumor location, spinal level, and extent
- ✓Assessment of neurological deficits and spinal cord function
- ✓Distinction from spinal cord tumor (C72.0) versus meningeal tumor