Z42.1 vs Z45.81
Z42.1 (Encounter for breast reconstruction following mastectomy) compared with Z45.81 (Encounter for adjustment or removal of breast implant), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. Z45.81 carries an Excludes1 note covering Z42.1: “encounter for breast reconstruction following mastectomy (Z42.1)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| Z42.1Encounter for breast reconstruction following mastectomy | Z45.81Encounter for adjustment or removal of breast implant | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99) | Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99) |
| Definition | Encounter for breast reconstruction following mastectomy is a billable ICD-10-CM diagnosis code (Z42.1). | Encounter for adjustment or removal of breast implant is a non-billable ICD-10-CM category code (Z45.81). |
| Includes | — | removal or replacement of implanted device Encounter for elective implant exchange (different material) (different size) Encounter for removal of tissue expander with or without synchronous insertion of permanent implant |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources