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C50.911 ICD-10-CM Code: Malignant neoplasm of unspecified site of right female breast

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
3 inclusion terms · 1 Excludes1 · 1 use-additional code
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 12 · RxHCC V08 category 22

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 582 — MASTECTOMY FOR MALIGNANCY WITH CC/MCC (MDC 09)
  • MS-DRG 583 — MASTECTOMY FOR MALIGNANCY WITHOUT CC/MCC (MDC 09)
  • MS-DRG 597 — MALIGNANT BREAST DISORDERS WITH MCC (MDC 09)
  • MS-DRG 598 — MALIGNANT BREAST DISORDERS WITH CC (MDC 09)
  • MS-DRG 599 — MALIGNANT BREAST DISORDERS WITHOUT CC/MCC (MDC 09)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 23 — Prostate, Breast, and Other Cancers and Tumors

Other models: CMS-HCC V22 HCC 12 · RxHCC V08 HCC 22

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for C50.911 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on C50.911 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • connective tissue of breast
  • Paget's disease of breast
  • Paget's disease of nipple

Source: inherited from C50

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from C50

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to identify estrogen, and other hormones and factors receptor status (Z17.-)

Source: inherited from C50

Code Overview

Malignant neoplasm of unspecified site of right female breast is a billable ICD-10-CM diagnosis code (C50.911).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Neoplasm Table Sites (1)

Anatomical sites from the official ICD-10-CM Table of Neoplasms that map to this code, with the matching behavior column.

  • Neoplasm, neoplastic, breast (connective tissue) (glandular tissue) (soft parts) — Malignant, Primary

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. Laterality is coded in this family. Confirm the documented side matches the code — the opposite-side siblings are in the relationships section. See the opposite-side sibling codes
  2. 1 Use Additional Code instruction — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  3. 1 Excludes1 entry — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

Other codes that name C50.911 or its code family, from the CMS ICD-10-CM tabular instructional notes, the CMS Table of Neoplasms and the CMS Table of Neoplasms (site match derived from the code title). Tabular-note edges are stored at the code family level that carries each note.

Referenced by 3 Excludes1 notes: C49 — Malignant neoplasm of other connective and soft tissue (via C50.-), C49.3 — Malignant neoplasm of connective and soft tissue of thorax (via C50.-), D05 — Carcinoma in situ of breast (via C50.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 3 Code First instructions across 2 chapters: D75.81 — Myelofibrosis (via C50.-), Z17 — Estrogen, and other hormones and factors receptor status (via C50.-), Z79.81 — Long term (current) use of agents affecting estrogen receptors and estrogen levels (via C50.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Referenced by 1 Code Also instruction: D61.82 — Myelophthisis (via C50.-).

These codes suggest coding this condition alongside when both are present.

Referenced by 5 Same-site neoplasm codes: C79.81 — Secondary malignant neoplasm of breast (via C50.9.-)Compare C50.911 vs C79.81 →, D05 — Carcinoma in situ of breast (via C50.9.-)Compare C50.911 vs D05 →, D24 — Benign neoplasm of breast (via C50.9.-)Compare C50.911 vs D24 →, D48.6 — Neoplasm of uncertain behavior of breast (via C50.9.-)Compare C50.911 vs D48.6 →, D49.3 — Neoplasm of unspecified behavior of breast (via C50.9.-)Compare C50.911 vs D49.3 →.

These codes represent related neoplasm behaviors affecting the same anatomic site.

Referenced by 5 Screening & history codes: Z12.3 — Encounter for screening for malignant neoplasm of breast (via C50.9.-)Compare C50.911 vs Z12.3 →, Z12.31 — Encounter for screening mammogram for malignant neoplasm of breast (via C50.9.-)Compare C50.911 vs Z12.31 →, Z12.39 — Encounter for other screening for malignant neoplasm of breast (via C50.9.-)Compare C50.911 vs Z12.39 →, Z80.3 — Family history of malignant neoplasm of breast (via C50.9.-)Compare C50.911 vs Z80.3 →, Z85.3 — Personal history of malignant neoplasm of breast (via C50.9.-)Compare C50.911 vs Z85.3 →.

These codes represent screening tests and history codes that refer to this active disease condition.

MS-DRG Grouper Relationships (FY2026)

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Potential MS-DRG participation — not a DRG assignment.

Named in the grouper logic of 5 MS-DRGs: DRG 582 (MDC 09), DRG 583 (MDC 09), DRG 597 (MDC 09), DRG 598 (MDC 09), DRG 599 (MDC 09).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):NEO030 — Breast cancer - all other types (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same condition, opposite side

Same category and title, differing only in which side of the body is affected.

C50.912 — Malignant neoplasm of unspecified site of left female breast (left)Compare C50.911 vs C50.912 →, C50.919 — Malignant neoplasm of unspecified site of unspecified female breast (unspecified)Compare C50.911 vs C50.919 →

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Prostate, Breast, and Other Cancers and Tumors) for risk-adjusted payment.

C50.619 — Malignant neoplasm of axillary tail of unspecified female breast, C50.621 — Malignant neoplasm of axillary tail of right male breast, C50.622 — Malignant neoplasm of axillary tail of left male breast, C50.629 — Malignant neoplasm of axillary tail of unspecified male breast, C50.811 — Malignant neoplasm of overlapping sites of right female breast, C50.812 — Malignant neoplasm of overlapping sites of left female breast, C50.819 — Malignant neoplasm of overlapping sites of unspecified female breast, C50.821 — Malignant neoplasm of overlapping sites of right male breast, C50.822 — Malignant neoplasm of overlapping sites of left male breast, C50.829 — Malignant neoplasm of overlapping sites of unspecified male breast, C50.912 — Malignant neoplasm of unspecified site of left female breast, C50.919 — Malignant neoplasm of unspecified site of unspecified female breast, C50.921 — Malignant neoplasm of unspecified site of right male breast, C50.922 — Malignant neoplasm of unspecified site of left male breast, C50.929 — Malignant neoplasm of unspecified site of unspecified male breast, C50.A0 — Malignant inflammatory neoplasm of unspecified breast, C50.A1 — Malignant inflammatory neoplasm of right breast, C50.A2 — Malignant inflammatory neoplasm of left breast, C54.0 — Malignant neoplasm of isthmus uteri, C54.1 — Malignant neoplasm of endometrium, +213 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic, Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers, Lung and Other Severe Cancers, Lymphoma and Other Cancers, Bladder, Colorectal, and Other Cancers

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Breast cancer - all other types).

C50.619 — Malignant neoplasm of axillary tail of unspecified female breast, C50.621 — Malignant neoplasm of axillary tail of right male breast, C50.622 — Malignant neoplasm of axillary tail of left male breast, C50.629 — Malignant neoplasm of axillary tail of unspecified male breast, C50.811 — Malignant neoplasm of overlapping sites of right female breast, C50.812 — Malignant neoplasm of overlapping sites of left female breast, C50.819 — Malignant neoplasm of overlapping sites of unspecified female breast, C50.821 — Malignant neoplasm of overlapping sites of right male breast, C50.822 — Malignant neoplasm of overlapping sites of left male breast, C50.829 — Malignant neoplasm of overlapping sites of unspecified male breast, C50.912 — Malignant neoplasm of unspecified site of left female breast, C50.919 — Malignant neoplasm of unspecified site of unspecified female breast, C50.921 — Malignant neoplasm of unspecified site of right male breast, C50.922 — Malignant neoplasm of unspecified site of left male breast, C50.929 — Malignant neoplasm of unspecified site of unspecified male breast, C50.A0 — Malignant inflammatory neoplasm of unspecified breast, C50.A1 — Malignant inflammatory neoplasm of right breast, C50.A2 — Malignant inflammatory neoplasm of left breast, D05.00 — Lobular carcinoma in situ of unspecified breast, D05.01 — Lobular carcinoma in situ of right breast, +45 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Carcinoma”, “Cancer”, “Adenocarcinoma”, …; these codes share that main term but sit in a different category of the Tabular List.

C4A.31 — Merkel cell carcinoma of nose (Merkel cell, nose), C4A.39 — Merkel cell carcinoma of other parts of face (Merkel cell, face, specified NEC), C4A.4 — Merkel cell carcinoma of scalp and neck (Merkel cell, neck), C4A.51 — Merkel cell carcinoma of anal skin (Merkel cell, anal skin), C4A.52 — Merkel cell carcinoma of skin of breast (Merkel cell, skin of breast), C4A.59 — Merkel cell carcinoma of other part of trunk (Merkel cell, trunk NEC), C4A.6 — Merkel cell carcinoma of upper limb, including shoulder (Merkel cell, shoulder), C4A.7 — Merkel cell carcinoma of lower limb, including hip (Merkel cell, hip), C4A.8 — Merkel cell carcinoma of overlapping sites (Merkel cell, overlapping sites), C4A.9 — Merkel cell carcinoma, unspecified (Merkel cell), C53.9 — Malignant neoplasm of cervix uteri, unspecified (solid, microinvasive, unspecified site), C56 — Malignant neoplasm of ovary (granulosa cell), C56.9 — Malignant neoplasm of unspecified ovary (ovarian), C58 — Malignant neoplasm of placenta (chorionic, unspecified site, female), C61 — Malignant neoplasm of prostate (duct, unspecified site, male), C62.90 — Malignant neoplasm of unspecified testis, unspecified whether descended or undescended (Sertoli cell, unspecified site), C64 — Malignant neoplasm of kidney, except renal pelvis (renal cell), C73 — Malignant neoplasm of thyroid gland (Hurthle cell), C74.0 — Malignant neoplasm of cortex of adrenal gland (adrenal cortical), C75.0 — Malignant neoplasm of parathyroid gland (water-clear cell), +36 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

CEA Test, Gamma-glutamyl Transferase (GGT) Test, Iron Panel

Contextual Map

Every relationship of C50.911 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run C50.911 with these 7 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Code First instructions

Referenced by Code Also instructions

  • D61.82 — Myelophthisis[Code Also](via C50.-): “malignant neoplasm of breast (C50.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Same-site neoplasm codes

Referenced by Screening & history codes MedCoder-derived

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 23 — Prostate, Breast, and Other Cancers and Tumors [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 09 — Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast[MDC crossing]: “Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 7,376 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Neoplasm sites

  • Neoplasm, neoplastic, breast (connective tissue) (glandular tissue) (soft parts) — Neoplasm, neoplastic, breast (connective tissue) (glandular tissue) (soft parts) — Malignant, Primary [Neoplasm table]: “Neoplasm, neoplastic, breast (connective tissue) (glandular tissue) (soft parts) (Malignant, Primary)”— CMS Table of Neoplasms · icd10cm-fy2026

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Malignant neoplasm of unspecified site of right female breast

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to C50.911 in its code family, with their registry titles.

View all codes in the C50 family