C70.1 ICD-10-CM Code: Malignant neoplasm of spinal meninges
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of eye, brain and other parts of central nervous system (C69-C72)
C70.1
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMalignant 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.
Buddy Insight
Malignant neoplasm of the spinal meninges is rare and represents an aggressive cancer of the protective membrane surrounding the spinal cord.
CMS-HCC V28
MappedHCC 20
RAF 0.0
CMS-HCC V24
MappedHCC 10
RAF 0.675
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 10
RAF 0.0
RXHCC
MappedHCC 22
RAF 0.0
Code Trumping
Basket needed
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for C70.1 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for C70.1 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for C70.1 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for C70.1 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for C70.1 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for C70.1 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for C70.1 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
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 C70.1to 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
Commonly Confused Codes
- •C70.0 — Cerebral meninges: spinal is below the foramen magnum, cerebral is above — confirm the level
- •C72.0 — Spinal cord: meningeal tumors arise from the covering, spinal cord tumors arise from the cord itself
- •D32.1 — Benign neoplasm of spinal meninges: only code C70.1 for confirmed malignant tumors
- •C79.49 — Secondary neoplasm of other parts of nervous system: distinguish primary from metastatic disease to spinal meninges