diff --git a/internal/domain/references/encounter/encounter.go b/internal/domain/references/encounter/encounter.go
index 9ffa168d..b7e4c1d8 100644
--- a/internal/domain/references/encounter/encounter.go
+++ b/internal/domain/references/encounter/encounter.go
@@ -20,6 +20,7 @@ const (
 )
 const (
 	ECAmbulatory EncounterClass = "ambulatory"
+	ECOutpatient EncounterClass = "outpatient"
 	ECInpatient  EncounterClass = "inpatient"
 	ECEmergency  EncounterClass = "emergency"
 	ECRadiology  EncounterClass = "radiology"