MCMCB Pro
N65.1

N65.1Disproportion of reconstructed breast

Billable / specific codeICD-10-CM

N65.1 is a billable, specific ICD-10-CM code for disproportion of reconstructed breast. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Breast asymmetry between native breast and reconstructed breast
  • Disproportion between native breast and reconstructed breast

Other codes that can never be billed with N65.1

These codes carry an Excludes1 note pointing at N65.1. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading N65.1 alone.

  • N62Hypertrophy of breast
  • N64.81Ptosis of breast
  • N64.82Hypoplasia of breast
  • Z42.1Encounter for breast reconstruction following mastectomy

Risk adjustment

N65.1 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

N65.1 is named in 16 Medicare coverage policies 16 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52849Billing and Coding: Breast Imaging: Breast Echography (Sonography)/Breast MRI/Ductography
  • A56448Billing and Coding: Breast Imaging Mammography/Breast Echography (Sonography)/Breast MRI/Ductography
  • A56448Billing and Coding: Breast Imaging Mammography/Breast Echography (Sonography)/Breast MRI/Ductography
  • A56587Billing and Coding: Cosmetic and Reconstructive Surgery

How N65.1 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to N65.1.

  • Asymmetrybetween native and reconstructed breast
  • Disproportionbetween native and reconstructed breast
  • Complicationreconstructed breastasymmetry between native and reconstructed breast
  • Complicationreconstructed breastdisproportion between native and reconstructed breast

Related codes at this level

Codes that share N65. If N65.1 is not quite right, the correct code is usually one of these.

Questions about N65.1

Is N65.1 a billable ICD-10-CM code?
Yes. N65.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does N65.1 sit in the tabular list?
Diseases of the genitourinary system (N00-N99), in the block Disorders of breast (N60-N65).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.