ICD-10-CM 2027
ICD-10 code for breast acquired deformity
From the official ICD-10-CM alphabetic index entry “Deformity › breast (acquired)”. Page updated September 29, 2026.
About coding breast acquired deformity
The ICD-10-CM code for breast acquired deformity is N64.89 (Other specified disorders of breast). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on N64.89.
Within N64.8, choose N64.89 (Other specified disorders of breast) only when documentation doesn't support a more specific option: ptosis of breast (N64.81) and hypoplasia of breast (N64.82).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 600 (Non-Malignant Breast Disorders with CC/MCC, relative weight 0.9975) and DRG 601 (Non-Malignant Breast Disorders without CC/MCC, relative weight 0.6017), in MDC 09 (Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific breast acquired deformity codes (official index)
Common questions about breast acquired deformity ICD-10 codes
What is the ICD-10 code for breast acquired deformity?
- N64.89 — Other specified disorders of breast. More specific codes apply when the documentation supports them: Q83.9, N65.0.
What is the ICD-10 code for congenital breast acquired deformity?
- Q83.9 — Congenital malformation of breast, unspecified.
What is the ICD-10 code for reconstructed breast acquired deformity?
- N65.0 — Deformity of reconstructed breast.
Is N64.89 billable?
- Yes. N64.89 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can N64.89 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict N64.89 as a principal diagnosis.
Is N64.89 a CC or MCC?
- No. N64.89 is neither a CC nor an MCC under MS-DRG v44.0.