2027 ICD-10-CM Diagnosis Code C70.1Malignant neoplasm of spinal meninges
ICD-10-CM Codes›C00–D49›C69-C72›C70
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 20
- Chronic Condition
C70.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of spinal meninges. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 54 through 55. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 18 closely related codes. Coders also document this condition as malignant neoplasm of spinal arachnoid mater. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system cancers - brain.
For Medicare Advantage risk adjustment, C70.1 maps to CMS-HCC Category 20 (Lung and Other Severe Cancers) under the V28 model, adding a risk factor of about 1.136 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C70.1 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Malignant neoplasm of spinal arachnoid mater
- Malignant neoplasm of spinal dura mater
- Malignant neoplasm of spinal meninges
- Malignant neoplasm of spinal pia mater
- Primary malignant neoplasm of meninges
- Primary malignant neoplasm of spinal cord
- Primary malignant neoplasm of spinal dura mater
- Primary malignant neoplasm of spinal meninges
- Structural abnormality of spinal dura mater
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C70.1: its own notes plus those printed at Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Notes
General instructions on how these codes are used.
- Functional activity
- All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Morphology [Histology]
- Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Primary malignant neoplasms overlapping site boundaries
- A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Malignant neoplasm of ectopic tissue
- Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name C70.1, its category, or a range that includes it.
Applicable To 2
These notes mention C70.1.
Excludes1 1
These codes carry an Excludes1 note naming C70.1: they are not reported together with it, unless the two conditions are unrelated.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Malignant Meningeal Neoplasm
a primary or metastatic malignant tumor occurring in the meninges, which surround the brain and spinal cord. the most common are meningiomas.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| arachnoid › spinal | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
| dura (cranial) (mater) › spinal | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
| meninges › spinal (cord) | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
| pia mater › spinal | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
| spine, spinal (column) › dura mater | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
| spine, spinal (column) › membrane | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
| spine, spinal (column) › meninges | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
| spine, spinal (column) › pia mater | C70.1 | C79.49 | – | D32.1 | D42.1 | D49.7 |
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Convert C70.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C70.1Overview
What is the ICD-10 code for malignant neoplasm of spinal meninges?
The ICD-10-CM code for malignant neoplasm of spinal meninges is C70.1 (sometimes written as C701). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C70.1 (Malignant neoplasm of meninges) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of spinal meninges on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C70.1 group to?
When malignant neoplasm of spinal meninges is the principal diagnosis on an inpatient stay, it groups to MS-DRG 55, 54, with relative weights from 1.0291 to 1.5197 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C70.1 a CC or MCC?
CMS lists C70.1 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 18 closely related codes in its exclusion list.
What is the ICD-9 equivalent of C70.1?
Under the General Equivalence Mappings, malignant neoplasm of spinal meninges converts to ICD-9-CM 192.3 (mal neo spinal meninges). The mapping is a direct match.
What HCC is C70.1?
C70.1 (malignant neoplasm of spinal meninges) maps to CMS-HCC Category 20 (Lung and Other Severe Cancers), commonly written as HCC 20, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 10 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 22.
Does C70.1 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C70.1 adds a risk adjustment factor of about 1.136 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.672 to 1.214 depending on the payment segment). A more severe related category (HCC 17, HCC 18, and HCC 19) supersedes it when both are reported. See the full factor table on the HCC 20 category page.
