C50.922 vs Z12.3

C50.922 (Malignant neoplasm of unspecified site of left male breast) compared with Z12.3 (Encounter for screening for malignant neoplasm of breast), from the official CMS tabular data.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Summary

Z12.3 is the personal-history or screening code for the active disease C50.922 names, so the two are not interchangeable.

MedCoder-derived

What is different?

The conditions named, billing status and chapter.C50.922 is “Malignant neoplasm of unspecified site of left male breast”; Z12.3 is “Encounter for screening for malignant neoplasm of breast”. Z12.3 is a non-billable header; C50.922 is billable. C50.922 sits in C00-D49 — Neoplasms (C00-D49); Z12.3 in Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99).

Registry fact

Can these codes be reported together?

Not for the same condition.Z12.3 is the personal-history or screening code for the active disease C50.922 names. Site match derived from the code’s own title against the CMS/CDC Table of Neoplasms. A personal-history code describes a condition that no longer exists and is no longer being treated, so it is not interchangeable with the active-disease code.

MedCoder-derivedGuide: History codes (Z codes)

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code. C50.922 carries 1 Excludes1 note and Z12.3 carries 1 Excludes1 note covering other codes; the side-by-side table quotes them.

Official rule

Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code. Z12.3 carries 1 Excludes2 note covering other codes; the side-by-side table quotes them.

Official rule

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Is one a parent or header code?

One is a header.Z12.3 is a non-billable header, but C50.922 is not one of its subdivisions.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

Yes.History or screening versus active disease. Z12.3 is the personal-history or screening code for the active disease C50.922 names.

MedCoder-derivedGuide: History codes (Z codes)

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Review

Condition lifecycle relationship

Z12.3

Encounter for screening for malignant neoplasm of breast

↔

C50.922

Malignant neoplasm of unspecified site of left male breast

What we found

History or screening versus active disease.Z12.3 is the personal-history or screening code for the active disease C50.922 names.

Site match derived from the code’s own title against the CMS/CDC Table of Neoplasms. A personal-history code describes a condition that no longer exists and is no longer being treated, so it is not interchangeable with the active-disease code.

What to review

Report the history code when the condition no longer exists and is no longer treated; report the active-disease code while it is.

Guide: History codes (Z codes)Check these on a claim

Why it matters

A personal-history code describes a condition that no longer exists and is no longer being treated, so it is not interchangeable with the active-disease code for the same site.

Source / rule

CMS Table of Neoplasms (site match derived from the code title)

Side by side

	C50.922Malignant neoplasm of unspecified site of left male breast	Z12.3Encounter for screening for malignant neoplasm of breast
Billing status	Billable	Non-billable header Report instead: Z12.31, Z12.39
Classification	C00-D49 — Neoplasms (C00-D49)	Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99)
Definition	Malignant neoplasm of unspecified site of left male breast is a billable ICD-10-CM diagnosis code (C50.922).	Encounter for screening for malignant neoplasm of breast is a non-billable ICD-10-CM category code (Z12.3).
Includes	connective tissue of breast Paget's disease of breast Paget's disease of nipple	—
Excludes1	skin of breast (C44.501, C44.511, C44.521, C44.591)	encounter for diagnostic examination-code to sign or symptom
Excludes2	—	examinations related to pregnancy and reproduction (Z30-Z36, Z39.-)
Use additional code	code to identify estrogen, and other hormones and factors receptor status (Z17.-)	code to identify any family history of malignant neoplasm (Z80.-)

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

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Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources