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C50.922 vs D05

C50.922 (Malignant neoplasm of unspecified site of left male breast) compared with D05 (Carcinoma in situ 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

These codes should not be reported together because D05’s tabular entry lists C50.922 under Excludes1.

Official rule
What is different?

The conditions named and billing status.C50.922 is “Malignant neoplasm of unspecified site of left male breast”; D05 is “Carcinoma in situ of breast”. D05 is a non-billable header; C50.922 is billable.

Registry fact

Can these codes be reported together?

No.D05’s entry carries an Excludes1 note covering C50.922: “Paget's disease of breast or nipple (C50.-)”. Both may be reported only when the documentation shows the two conditions are unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes1 relationship?

Yes.D05’s tabular entry: “Paget's disease of breast or nipple (C50.-)”. The note covers C50.922.

Official ruleGuide: Excludes1 vs Excludes2

Is one a parent or header code?

One is a header.D05 is a non-billable header, but C50.922 is not one of its subdivisions.

Registry fact

Nothing found in 3 other checks; 1 check does not apply
Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code.

Official rule

Is one more specific?

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

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?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

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?

Excludes1 — generally not reported together

Excludes1 conflict

D05
Carcinoma in situ of breast
↔
C50.922
Malignant neoplasm of unspecified site of left male breast

What we found

No — do not report together.D05 carries an Excludes1 note covering C50.922: “Paget's disease of breast or nipple (C50.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

What to review

Report one of the two. Both may be reported only when the documentation shows the two conditions are unrelated to each other.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes1 note means the two conditions are not ordinarily reported together for the same encounter, because the classification treats them as mutually exclusive forms of the same condition. The documented exception is when the two conditions are unrelated to each other.

Source / rule

CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a

Official guidance behind these answers

  • Section I.A.12.a — Excludes1 · applies to: Excludes1

    A type 1 Excludes note is a pure excludes note. It means “NOT CODED HERE!” An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition. An exception to the Excludes1 definition is the circumstance when the two conditions are unrelated to each other. If it is not clear whether the two conditions involving an Excludes1 note are related or not, query the provider. For example, code F45.8, Other somatoform disorders, has an Excludes1 note for "sleep related teeth grinding (G47.63)," because "teeth grinding" is an inclusion term under F45.8. Only one of these two codes should be assigned for teeth grinding. However psychogenic dysmenorrhea is also an inclusion term under F45.8, and a patient could have both this condition and sleep related teeth grinding. In this case, the two conditions are clearly unrelated to each other, and so it would be appropriate to report F45.8 and G47.63 together.

    ICD-10-CM Official Guidelines FY2027

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

Similar descriptions do not make codes interchangeable. The documentation and the official instructions decide which code applies.

Official descriptionDiffers
C50.922

Malignant neoplasm of unspecified site of left male breast

D05

Carcinoma in situ of breast

StatusDiffers
C50.922
Billable
D05
Non-billable header

A header is not reported on a claim; a code beneath it is.

Report instead: D05.00, D05.01, D05.02, D05.10, D05.11

Excludes1Differs
C50.922
  • skin of breast (C44.501, C44.511, C44.521, C44.591)
D05
  • carcinoma in situ of skin of breast (D04.5)
  • melanoma in situ of breast (skin) (D03.5)
  • Paget's disease of breast or nipple (C50.-)
  • malignant neoplasm of breast (C50.-)
Use additional codeDiffers
C50.922
  • code to identify estrogen, and other hormones and factors receptor status (Z17.-)
D05

None at this code

CategoryDiffers
C50.922

C50 Malignant neoplasm of breast

D05

Is itself a category

ChapterSame for both

C00-D49 — Neoplasms (C00-D49)

IncludesDiffers
C50.922
  • connective tissue of breast
  • Paget's disease of breast
  • Paget's disease of nipple
D05
  • Bowen's disease
  • erythroplasia
  • grade III intraepithelial neoplasia
  • Queyrat's erythroplasia

No Excludes2, Code first, Code also and 7th character note at either code.

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. In a row that differs, each code’s own notes are listed under it, and the notes every code shares are listed once beneath them.

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