C50.A1 (Malignant inflammatory neoplasm of right breast) compared with C50.A2 (Malignant inflammatory neoplasm of left breast), from the official CMS tabular data. C50.A1 and C50.A2 code the same condition on opposite sides.
Same condition; these differ only in which side is documented.
These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.
Source: ICD-10-CM tabular list (laterality variant derived from the code title)
Same condition, opposite side. C50.A1 and C50.A2 name the same condition on opposite sides of the body.
Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.
| C50.A1Malignant inflammatory neoplasm of right breast | C50.A2Malignant inflammatory neoplasm of left breast | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Malignant inflammatory neoplasm of right breast is a billable ICD-10-CM diagnosis code (C50.A1). | Malignant inflammatory neoplasm of left breast is a billable ICD-10-CM diagnosis code (C50.A2). |
| Includes | connective tissue of breast Paget's disease of breast Paget's disease of nipple | connective tissue of breast Paget's disease of breast Paget's disease of nipple |
| Use additional code | code to identify estrogen, and other hormones and factors receptor status (Z17.-) | code to identify estrogen, and other hormones and factors receptor status (Z17.-) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources