D01.3 vs D04.5
D01.3 and D04.5 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on D01.3
carcinoma in situ of anal margin (D04.5)
D01.3
Carcinoma in situ of anus and anal canal
Billable
- Chapter 2
- Neoplasms
- Section
- D00-D09
Use when the record says
- Anal intraepithelial neoplasia III [AIN III]
- Severe dysplasia of anus
Indexed under
- Dysplasia › anus › severe
- Neoplasia › intraepithelial › anal › severe
D04.5
Carcinoma in situ of skin of trunk
Billable
- Chapter 2
- Neoplasms
- Section
- D00-D09
Use when the record says
- Carcinoma in situ of anal margin
- Carcinoma in situ of anal skin
- Carcinoma in situ of perianal skin
- Carcinoma in situ of skin of breast
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027