D32.9 (Benign neoplasm of meninges, unspecified) compared with D42.9 (Neoplasm of uncertain behavior of meninges, unspecified), from the official CMS tabular data. D32.9 and D42.9 name the same anatomical site (arachnoid) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — uncertain behavior (arachnoid)
The behavior documented for the site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column of the neoplasm table, and therefore which code, applies.
Source: CMS Table of Neoplasms
Same site, different neoplasm behavior. D32.9 and D42.9 name the same anatomical site (arachnoid) with a different neoplasm behavior.
From the CMS Table of Neoplasms: the behavior documented for that site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column, and therefore which code, applies.
| D32.9Benign neoplasm of meninges, unspecified | D42.9Neoplasm of uncertain behavior of meninges, unspecified | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Benign neoplasm of meninges, unspecified is a billable ICD-10-CM diagnosis code (D32.9). | Neoplasm of uncertain behavior of meninges, unspecified is a billable ICD-10-CM diagnosis code (D42.9). |
| Includes | Meningioma NOS | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources