ICD-10-CM 2027 diagnosis code

N63Unspecified lump in breast

Not billable — use a more specific code

N63 is a header code, so it can't be reported by itself. Choose one of the 5 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

N63 is the ICD-10-CM diagnosis code for unspecified lump in breast. It belongs to 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 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: N63.0 (breast), N63.1 (breast), N63.2 (breast), N63.3 (tail) and N63.4 (subareolar).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2018 (expanded into subcodes).

Specific codes under N63

Coding notes

Applicable toConditions and synonyms classified to this code

Nodule(s) NOS in breast

Notes that apply from higher levels

Instructions written at a parent level also apply to N63.

Broader instructions also apply from N60-N65 Disorders of breast and Chapter 14: Diseases of the genitourinary system.

Codes whose notes reference N63

R22.2Excludes2

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
FY2018 (effective 10/1/2017): Expanded — no longer billable

Common questions about N63

Is N63 billable?: No. N63 is a header code. Report one of its more specific subcodes instead.