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ICD-10-CM 2027 diagnosis code

C50.51Malignant neoplasm of lower-outer quadrant of breast, female

Not billable — use a more specific code

C50.51 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About C50.51

C50.51 is the ICD-10-CM diagnosis code for malignant neoplasm of lower-outer quadrant of breast, female. It belongs to category C50 (malignant neoplasm of breast), block C50 (malignant neoplasms of breast) and chapter 2 (neoplasms). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within C50.5 (malignant neoplasm of lower-outer quadrant of breast), C50.51 is specifically for malignant neoplasm of lower-outer quadrant of breast, female. Related codes cover male (C50.52).

To report this condition, pick the subcode that matches the documentation: C50.511 (breast), C50.512 (breast) and C50.519 (breast).

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

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under C50.51

Notes that apply from higher levels

Instructions written at a parent level also apply to C50.51.

› From C50 Malignant neoplasm of breast
Includes
  • connective tissue of breast
  • Paget's disease of breast
  • Paget's disease of nipple
Excludes1
Use additional code
  • code to identify estrogen, and other hormones and factors receptor status (Z17.-)

Broader instructions also apply from Chapter 2: Neoplasms.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about C50.51

Is C50.51 billable?

No. C50.51 is a header code. Report one of its more specific subcodes instead.