C71.8 (Malignant neoplasm of overlapping sites of brain) compared with D49.6 (Neoplasm of unspecified behavior of brain), from the official CMS tabular data. C71.8 and D49.6 name the same anatomical site (brain) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — unspecified behavior (brain)
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. C71.8 and D49.6 name the same anatomical site (brain) 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.
| C71.8Malignant neoplasm of overlapping sites of brain | D49.6Neoplasm of unspecified behavior of brain | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of overlapping sites of brain is a billable ICD-10-CM diagnosis code (C71.8). | Neoplasm of unspecified behavior of brain is a billable ICD-10-CM diagnosis code (D49.6). |
| Includes | — | 'growth' NOS neoplasm NOS new growth NOS tumor NOS |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources