D36.9 (Benign neoplasm, unspecified site) compared with D49.9 (Neoplasm of unspecified behavior of unspecified site), from the official CMS tabular data. D36.9 and D49.9 name the same anatomical site (unspecified site) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — unspecified behavior (unspecified site)
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. D36.9 and D49.9 name the same anatomical site (unspecified site) 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.
| D36.9Benign neoplasm, unspecified site | D49.9Neoplasm of unspecified behavior of unspecified site | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Benign neoplasm, unspecified site is a billable ICD-10-CM diagnosis code (D36.9). | Neoplasm of unspecified behavior of unspecified site is a billable ICD-10-CM diagnosis code (D49.9). |
| 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