Excludes1 pair

Q74.1 vs Q87.2

Q74.1 and Q87.2 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 Q74.1
nail patella syndrome (Q87.2)
Q74.1

Congenital malformation of knee

Billable
Chapter 17
Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
Section
Q65-Q79
Use when the record says
  • Congenital absence of patella
  • Congenital dislocation of patella
  • Congenital genu valgum
  • Congenital genu varum
  • Rudimentary patella
Indexed under
  • Absence › patella, congenital
  • Agenesis › patella
  • Anomaly, anomalous › knee
  • Anomaly, anomalous › patella
  • Bifid › patella
Q87.2

Congenital malformation syndromes predominantly involving limbs

Billable
Chapter 17
Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
Section
Q80-Q89
Use when the record says
  • Holt-Oram syndrome
  • Klippel-Trenaunay-Weber syndrome
  • Nail patella syndrome
  • Rubinstein-Taybi syndrome
  • Sirenomelia syndrome
  • Thrombocytopenia with absent radius [TAR] syndrome
  • VATER syndrome
Indexed under
  • Fong's syndrome (hereditary osteo-onychodysplasia)
  • Holt-Oram syndrome
  • Klippel-Trenaunay syndrome (-Weber)
  • Mietens' syndrome
  • Onycho-osteodysplasia

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