C51 vs D07.1
C51 and D07.1 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 C51
carcinoma in situ of vulva (D07.1)
D07.1
Carcinoma in situ of vulva
Billable
- Chapter 2
- Neoplasms
- Section
- D00-D09
Use when the record says
- Severe dysplasia of vulva
- Vulvar intraepithelial neoplasia III [VIN III]
Indexed under
- Dysplasia › vulva › severe NEC
- Neoplasia › intraepithelial › vulva › grade III
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