N63.42 — Unspecified lump in left breast, subareolar
N63.42 is a billable, specific ICD-10-CM code for unspecified lump in left breast, subareolar. It is valid for submission on a claim.
Risk adjustment
N63.42 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
N63.42 is named in 4 Medicare coverage policies — 4 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
- A56580Billing and Coding: Computerized Axial Tomography (CT), Thorax
How N63.42 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 N63.42.
- Lump›breast›subareolar›left
Related codes at this level
Codes that share N63.4. If N63.42 is not quite right, the correct code is usually one of these.
Questions about N63.42
- Is N63.42 a billable ICD-10-CM code?
- Yes. N63.42 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does N63.42 sit in the tabular list?
- Diseases of the genitourinary system (N00-N99), in the block Disorders of breast (N60-N65).