ICD-10 Code for Carcinoma-in-situ

The ICD-10-CM 2027 alphabetic index lists carcinoma-in-situ with the subterms below. More specific codes depend on the details documented, as listed in the official index (7 codes, 1 billable).

Index entries for Carcinoma-in-situ

breast NOS – D05.9- (header)
- specified type NEC – D05.8- (header)
epidermoid – see also Neoplasm, in situ, by site
- with questionable stromal invasion
  - cervix – D06.9
  - specified site NEC – see Neoplasm, in situ, by site
  - unspecified site – D06.9
- Bowen's type – see Neoplasm, skin, in situ
intraductal
- breast – D05.1- (header)
- specified site NEC – see Neoplasm, in situ, by site
- unspecified site – D05.1- (header)
lobular
- with
  - infiltrating duct
    - breast (female) – C50.91- (header)
      - male – C50.92- (header)
    - specified site NEC – see Neoplasm, malignant
    - unspecified site (female) – C50.91- (header)
      - male – C50.92- (header)
  - intraductal
    - breast – D05.8- (header)
    - specified site NEC – see Neoplasm, in situ, by site
    - unspecified site (female) – D05.8- (header)
- breast – D05.0- (header)
- specified site NEC – see Neoplasm, in situ, by site
- unspecified site – D05.0- (header)
squamous cell – see also Neoplasm, in situ, by site
- with questionable stromal invasion
  - cervix – D06.9
  - specified site NEC – see Neoplasm, in situ, by site
  - unspecified site – D06.9

How to choose the right code

Start with the main term, then pick the indented subterm that matches the documentation (type, cause, site, laterality, episode of care). Always confirm the code in the tabular list: follow its Excludes1/Excludes2, “code first” and “use additional code” notes, and add a 7th character where required.

Source: CDC/NCHS ICD-10-CM FY2027 alphabetic index.