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C50.A0 vs C50.A1

C50.A0 (Malignant inflammatory neoplasm of unspecified breast) compared with C50.A1 (Malignant inflammatory neoplasm of right breast), from the official CMS tabular data. C50.A0 and C50.A1 code the same condition on opposite sides.

Relationship

Review

Laterality relationship

C50.A0
Unspecified
Malignant inflammatory neoplasm of unspecified breast
C50.A1
Right
Malignant inflammatory neoplasm of right breast

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)

Can these codes be reported together?

Same condition, opposite side. C50.A0 and C50.A1 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.

Side by side

C50.A0Malignant inflammatory neoplasm of unspecified breastC50.A1Malignant inflammatory neoplasm of right breast
Billing statusBillableBillable
ClassificationC00-D49 — Neoplasms (C00-D49)C00-D49 — Neoplasms (C00-D49)
DefinitionMalignant inflammatory neoplasm of unspecified breast is a billable ICD-10-CM diagnosis code (C50.A0).Malignant inflammatory neoplasm of right breast is a billable ICD-10-CM diagnosis code (C50.A1).
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