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C50.6 ICD-10-CM Code: Malignant neoplasm of axillary tail of breast

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FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of breast (C50)

C50.6

Header CodeICD-10-CMOfficial ICD-10-CMCodebook guidance

Malignant neoplasm of axillary tail of breast

Malignant neoplasm of axillary tail of breast

CMS-HCC V28

0

0

RAF 0

CMS-HCC V24

0

0

RAF 0

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

0

0

RAF 0

Code Trumping

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Code Book Path

Official
C50Malignant neoplasm of breast
C50.6Malignant neoplasm of axillary tail of breast

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for C50.6 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C50.6 in this effective period.

Related Child Codes

Official
C50.61Malignant neoplasm of axillary tail of breast, female
C50.62Malignant neoplasm of axillary tail of breast, male

Includes

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

Excludes 1

Official
  • skin of breast (C44.501, C44.511, C44.521, C44.591)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C50.6 in this effective period.

Use Additional

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

Code Also

Official

ICD-10-CM does not list Code Also instructions for C50.6 in this effective period.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

What This Code Means

C50.6 is the ICD-10-CM diagnosis code for malignant neoplasm of axillary tail of breast. C50.6 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of breast (c50).

Header codes like C50.6 cannot be reported on claims directly, they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at C50.6's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for C50.6 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Child Codes

Code Hierarchy

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