2026 ICD-10-CM Diagnosis Code D42.1Neoplasm of uncertain behavior of spinal meninges

ICD-10-CM CodesC00–D49D37-D48D42

ICD-10-CM D42.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D42.1 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of spinal meninges. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as neoplasm of uncertain behavior of meninges. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.

Code Identity

ICD-10-CM Code
D42.1
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of uncertain behavior of spinal meninges
Short Description
Neoplasm of uncertain behavior of spinal meninges
Same as the full description in the CMS dataset.
Parent Code
Neoplasm of uncertain behavior of meninges

Code Classification

ChapterC00–D49Neoplasms
SectionD37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
CategoryD42Neoplasm of uncertain behavior of meninges
This CodeD42.1Neoplasm of uncertain behavior of spinal meninges

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Neoplasm of uncertain behavior of meninges
  • Neoplasm of uncertain behavior of spinal cord
  • Neoplasm of uncertain behavior of spinal intradural extramedullary space
  • Neoplasm of uncertain behavior of spinal intradural intramedullary space
  • Neoplasm of uncertain behavior of spinal meninges

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO072
Neoplasms of unspecified nature or uncertain behavior
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
arachnoid spinalC70.1C79.49D32.1D42.1D49.7
dura (cranial) (mater) spinalC70.1C79.49D32.1D42.1D49.7
meninges spinal (cord)C70.1C79.49D32.1D42.1D49.7
pia mater spinalC70.1C79.49D32.1D42.1D49.7
spine, spinal (column) dura materC70.1C79.49D32.1D42.1D49.7
spine, spinal (column) membraneC70.1C79.49D32.1D42.1D49.7
spine, spinal (column) meningesC70.1C79.49D32.1D42.1D49.7
spine, spinal (column) pia materC70.1C79.49D32.1D42.1D49.7

Patient EducationClinical

Spinal Cord Diseases

Your spinal cord is a bundle of nerves that runs down the middle of your back. It carries signals back and forth between your body and your brain. It is protected by your vertebrae, which are the bone disks that make up your spine.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert D42.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
237.6 Unc behav neo meninges
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D42.1Overview

Is D42.1 (Neoplasm of uncertain behavior of meninges) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report neoplasm of uncertain behavior of spinal meninges on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of D42.1?

Under the General Equivalence Mappings, neoplasm of uncertain behavior of spinal meninges converts to ICD-9-CM 237.6 (unc behav neo meninges). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.