What is ICD-10 code C70.1?

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 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C70.1 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. C70.1 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. C70.1 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does C70.1 map to under V28?

C70.1 maps to CMS-HCC V28 HCC 20 (Lung and Other Severe Cancers). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM C70.1: Malignant neoplasm of spinal

C70.1 maps to CMS-HCC V28 20. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

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Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupC70.1Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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 guidance

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.

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

Mapped

HCC 20

Lung and Other Severe Cancers

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 009

HHS-HCC 009 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

Code-level coefficient reference

RXHCC

Mapped

HCC 22

Prostate, Breast, Bladder, an...

Code-level coefficient reference

Code Book Path

Official

C70Malignant neoplasm of meninges

C70.1Malignant neoplasm of spinal meninges

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for C70.1 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C70.1 in this effective period.

Related Child Codes

Official

C70.0Malignant neoplasm of cerebral meninges

C70.9Malignant neoplasm of meninges, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for C70.1 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C70.1 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C70.1 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C70.1 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C70.1 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

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

MEAT Support

HCC Buddy guidance

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

Audit Caution

HCC Buddy guidance

Confusing meningeal tumors with intramedullary spinal cord tumors — different anatomical compartments

Coding benign spinal meningiomas as malignant — most spinal meningiomas are benign (D32.1)

Failing to distinguish primary malignant meningeal tumors from leptomeningeal metastasis from systemic cancer

Not specifying cerebral versus spinal meningeal location

Common Mistakes

HCC Buddy guidance

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

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is C70.1 an HCC code?

Yes. C70.1 (Malignant neoplasm of spinal meninges) maps to HCC 20, Lung and Other Severe Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.136. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: C70.1 is billable and maps to V28 HCC 20, Lung and Other Severe Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C70.1
Description: Malignant neoplasm of spinal meninges
HCC (V28): HCC 20 — Lung and Other Severe Cancers
RAF reference coefficient: 1.136
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 20, Lung and Other Severe Cancers

1.136

ESRDHCC 10, Lymphoma and Other Cancers

Not separately weighted

RxHCCHCC 22, Prostate, Breast, Bladder, and Other Cancers and Tumors

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work C70.1 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

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.

Coder workflow notes

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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 source-labeled community, non-dual, aged reference coefficient of 1.136. No V24 mapping is shown for C70.1; use the applicable model and payment year when reviewing the V28 mapping. 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. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Ensure documentation specifies that the neoplasm is in the spinal meninges, not the brain meninges (C70.0). Because C70.1 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. 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, source-labeled coefficient references, 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