N64.82 Hypoplasia of breast

Billable ICD-10-CM code, FY2026.

Applicable to

• Micromastia

Excludes1 (never code together)

• congenital absence of breast (Q83.0)
• hypoplasia of native breast in relation to reconstructed breast (N65.1)

Applies from N64 Other disorders of breast

Excludes2 (not included here)

• mechanical complication of breast prosthesis and implant (T85.4-)

MS-DRG index

Defines the logic of DRG(s) 600-601 in MDC 09.

Approximate ICD-9-CM (GEMs)

• 611.82 Hypoplasia of breast

Medicare Code Edits (MCE v43.1 (April 2026))

• Adult diagnoses (age 15 through 124): Age conflict edit. These diagnoses are clinically expected only in patients age 15 through 124.

Code annotations containing back-references to N64.82

Back-references to N64.82

• Type 2 Excludes: Q83 Congenital malformations of breast ("hypoplasia of breast (N64.82)")
• Type 2 Excludes: Q83 Congenital malformations of breast ("micromastia (N64.82)")

Diagnosis Index entries for N64.82

• Hypoplasia, hypoplastic › breast (areola)
• Micromastia

Nearby codes

• N64.52 Nipple discharge
• N64.53 Retraction of nipple
• N64.59 Other signs and symptoms in breast
• N64.8 Other specified disorders of breast
• N64.81 Ptosis of breast
• N64.82 Hypoplasia of breast (this code)
• N64.89 Other specified disorders of breast
• N64.9 Disorder of breast, unspecified