D09.3 (Carcinoma in situ of thyroid and other endocrine glands) compared with D35.1 (Benign neoplasm of parathyroid gland), from the official CMS tabular data. D09.3 and D35.1 name the same anatomical site (parathyroid) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — carcinoma in situ (parathyroid)
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. D35.1 and D09.3 name the same anatomical site (parathyroid) with a different neoplasm behavior.
From the CMS/CDC 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.
| D09.3Carcinoma in situ of thyroid and other endocrine glands | D35.1Benign neoplasm of parathyroid gland | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Carcinoma in situ of thyroid and other endocrine glands is a billable ICD-10-CM diagnosis code (D09.3). | Benign neoplasm of parathyroid gland is a billable ICD-10-CM diagnosis code (D35.1). |
| Includes | Bowen's disease erythroplasia grade III intraepithelial neoplasia Queyrat's erythroplasia | — |
| Use additional code | — | code to identify any functional activity |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources