L81 vs Q82.5
L81 and Q82.5 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 L81
birthmark NOS (Q82.5)
L81
Other disorders of pigmentation
Not billable
- Chapter 12
- Diseases of the skin and subcutaneous tissue
- Section
- L80-L99
Q82.5
Congenital non-neoplastic nevus
Billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q80-Q89
Use when the record says
- Birthmark NOS
- Flammeus Nevus
- Portwine Nevus
- Sanguineous Nevus
- Strawberry Nevus
- Vascular Nevus NOS
- Verrucous Nevus
Indexed under
- Birthmark
- Port wine nevus, mark, or stain
- Mark › port wine
- Mark › raspberry
- Mark › strawberry
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
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