ICD-10 · PDGM grouping
N64 Other disorders of breast
All 13 codes in the N64 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
13
Can lead a claim
12
Cannot lead a claim
1
What CMS assigns to N64
12 of the 13 codes group to MMTA - Gastrointestinal tract and Genitourinary system (8), MMTA - Other (3) and Wound (1); 1 is assigned no clinical group. None of the 13 is assigned a comorbidity subgroup. 12 of the 13 can lead a claim. CMS attaches a code-first note to 1 of the 13.
Code first
CMS grouper convention 142, on N64.1. Code first:
- breast necrosis due to breast graft (T85.898)
Every code in N64
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| N64.0 | Fissure and fistula of nipple | Can lead a claim | C | None |
| N64.1 | Fat necrosis of breast | Can lead a claim, code first applies | J | None |
| N64.2 | Atrophy of breast | Can lead a claim | A | None |
| N64.3 | Galactorrhea not associated with childbirth | Can lead a claim | J | None |
| N64.4 | Mastodynia | Can lead a claim | J | None |
| N64.5 Other signs and symptoms in breast | ||||
| N64.51 | Induration of breast | Can lead a claim | J | None |
| N64.52 | Nipple discharge | Can lead a claim | J | None |
| N64.53 | Retraction of nipple | Can lead a claim | A | None |
| N64.59 | Other signs and symptoms in breast | Can lead a claim | J | None |
| N64.8 Other specified disorders of breast | ||||
| N64.81 | Ptosis of breast | Can lead a claim | J | None |
| N64.82 | Hypoplasia of breast | Can lead a claim | A | None |
| N64.89 | Other specified disorders of breast | Can lead a claim | J | None |
| N64.9 | Disorder of breast, unspecified | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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