C50.311 (Malignant neoplasm of lower-inner quadrant of right female breast) compared with C50.312 (Malignant neoplasm of lower-inner quadrant of left female breast), from the official CMS tabular data. C50.311 and C50.312 code the same condition on opposite sides. MedCoder-derived
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. C50.311 and C50.312 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.
| C50.311Malignant neoplasm of lower-inner quadrant of right female breast | C50.312Malignant neoplasm of lower-inner quadrant of left female breast | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of lower-inner quadrant of right female breast is a billable ICD-10-CM diagnosis code (C50.311). | Malignant neoplasm of lower-inner quadrant of left female breast is a billable ICD-10-CM diagnosis code (C50.312). |
| 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