ICD-10-CM 2027 diagnosis code
N63.4Unspecified lump in breast, subareolar
N63.4 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.
Code last changed in FY2018 (effective October 1, 2017). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About N63.4
N63.4 is the ICD-10-CM diagnosis code for unspecified lump in breast, subareolar. It belongs to category N63 (unspecified lump in breast), block N60-N65 (disorders of breast) and chapter 14 (diseases of the genitourinary system). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.
Within N63 (unspecified lump in breast), N63.4 is specifically for unspecified lump in breast, subareolar. Related codes cover unspecified breast (N63.0), the right breast (N63.1), the left breast (N63.2) and axillary tail (N63.3).
To report this condition, pick the subcode that matches the documentation: N63.41 (subareolar) and N63.42 (subareolar).
It was added in FY2018, effective October 1, 2017.
Specific codes under N63.4
Notes that apply from higher levels
Instructions written at a parent level also apply to N63.4.
Broader instructions also apply from N60-N65 Disorders of breast and Chapter 14: Diseases of the genitourinary system.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2018 (effective 10/1/2017): Added
- No changes since FY2018.
Common questions about N63.4
Is N63.4 billable?
- No. N63.4 is a header code. Report one of its more specific subcodes instead.