D42.0
Neoplasm of uncertain behavior of cerebral meninges
D42.0 (also written D420) is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of cerebral meninges. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 3 codes in category D42 (Neoplasm of uncertain behavior of meninges). Its coding notes include 1 Excludes1 entry.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Neuro Rehabilitation clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026IRF 60% Rule
On the CMS list of diagnoses used to determine presumptive compliance with the IRF 60 percent rule.
Source: CMS IRF Presumptive Compliance-3, FY 2027 IRF PPS final rule files, effective for discharges on or after October 1, 2026IPF Comorbidity
On the CMS IPF comorbidity list.
| Comorbidity category | Factor |
|---|---|
| Oncology Treatment | 1.44 |
Notes
Also from chapter/block level (9 notes)
- Categories D37-D44, and D48 classify by site neoplasms of uncertain behavior, i.e., histologic confirmation whether the neoplasm is malignant or benign cannot be made.
- 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).