Excludes1 pair

H04- vs Q10.6

H04 and Q10.6 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 H04
congenital malformations of lacrimal system (Q10.4-Q10.6)
H04

Disorders of lacrimal system

Not billable
Chapter 7
Diseases of the eye and adnexa
Section
H00-H05
Q10.6

Other congenital malformations of lacrimal apparatus

Billable
Chapter 17
Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
Section
Q10-Q18
Use when the record says
  • Congenital malformation of lacrimal apparatus NOS
Indexed under
  • Accessory › lacrimal canal
  • Anomaly, anomalous › caruncle, lacrimal
  • Anomaly, anomalous › lacrimal apparatus or duct
  • Deformity › lacrimal passages or duct NEC (congenital)
  • Displacement, displaced › canaliculus, congenital (lacrimalis)

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