Excludes1 pair
Q18.4 vs Q38-
Q18.4 and Q38 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 Q38
macrostomia (Q18.4)
Q18.4
Macrostomia
Billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q10-Q18
Indexed under
- Macrostomia (congenital)
- Meloschisis
Q38
Other congenital malformations of tongue, mouth and pharynx
Not billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q38-Q45
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