Other disorders of breast (N64) ICD-10-CM
The N64 code range covers other disorders of breast with 16 ICD-10-CM diagnosis codes. 13 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- mechanical complication of breast prosthesis and implant T85.4
Codes in the N64 Range 16 codes · 13 billable
- N64 Other disorders of breastNon-billable
- N64.0 Fissure and fistula of nipple
- N64.1 Fat necrosis of breast
- N64.2 Atrophy of breast
- N64.3 Galactorrhea not associated with childbirth
- N64.4 Mastodynia
- N64.5 Other signs and symptoms in breastNon-billable
- N64.51 Induration of breast
- N64.52 Nipple discharge
- N64.53 Retraction of nipple
- N64.59 Other signs and symptoms in breast
- N64.8 Other specified disorders of breastNon-billable
- N64.81 Ptosis of breast
- N64.82 Hypoplasia of breast
- N64.89 Other specified disorders of breast
- N64.9 Disorder of breast, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the N64 range.
Breast Fat Necrosis
Localized necrosis of the adipose tissue in the breast. Clinically, it may present as a mass. Causes include injury, surgical procedures, and radiation treatment.
Mastodynia
Pain in the breast generally classified as cyclical (associated with menstrual periods), or noncyclical, i.e. originating from the breast or nearby muscles or joints, ranging from minor discomfort to severely incapacitating.
About the N64 Code Range
These breast disorders include nipple fissures and fistulas, fat necrosis, atrophy, discharge unrelated to childbirth, and pain. The categories distinguish specific disorders, other signs and symptoms, other specified disorders, and an unspecified disorder.
N64.0 addresses nipple fissures and fistulas. N64.1 and N64.2 identify fat necrosis and breast atrophy. N64.3 identifies milk discharge unrelated to childbirth, while N64.4 identifies breast pain.
Under N64.5, signs and symptoms split into breast hardening, nipple discharge, nipple retraction, and other findings. Under N64.8, specified disorders split into breast drooping, underdevelopment, and other specified disorders. N64.9 identifies an unspecified breast disorder.
Questions About This Page
How many billable codes are in the N64 range?
Of the 16 codes in this range, 13 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the N64 range classify?
The range classifies other disorders of breast. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
