Excludes1 pair

D00.0- vs D03.0

D00.0 and D03.0 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.

The official note, declared on D00.0

carcinoma in situ of skin of lip (D03.0, D04.0)

D00.0

Carcinoma in situ of lip, oral cavity and pharynx

Not billable

Chapter 2: Neoplasms
Section: D00-D09

D03.0

Melanoma in situ of lip

Billable

Chapter 2: Neoplasms
Section: D00-D09

Indexed under

Melanoma › in situ › lip (lower) (upper)

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