diff --git a/schema/definitions/0.8.0/schema/fmu_results.json b/schema/definitions/0.8.0/schema/fmu_results.json
index fe9cc24d0..3646e8892 100644
--- a/schema/definitions/0.8.0/schema/fmu_results.json
+++ b/schema/definitions/0.8.0/schema/fmu_results.json
@@ -32,6 +32,7 @@
     "fmu.realization.id",
     "fmu.realization.name",
     "fmu.realization.uuid",
+    "fmu.realization.is_reference",
     "fmu.workflow",
     "masterdata",
     "source",
@@ -6137,6 +6138,11 @@
           "title": "Id",
           "type": "integer"
         },
+        "is_reference": {
+          "default": false,
+          "title": "Is Reference",
+          "type": "boolean"
+        },
         "jobs": {
           "anyOf": [
             {},
diff --git a/src/fmu/dataio/_model/fields.py b/src/fmu/dataio/_model/fields.py
index f09bbc125..a20cbe4da 100644
--- a/src/fmu/dataio/_model/fields.py
+++ b/src/fmu/dataio/_model/fields.py
@@ -298,6 +298,9 @@ class Realization(BaseModel):
     """The universally unique identifier for this realization. It is a hash of
     ``fmu.case.uuid`` and ``fmu.iteration.uuid`` and ``fmu.realization.id``."""
 
+    is_reference: bool = Field(default=False)
+    """Flag used to determine if this relization is tagged as a reference."""
+
 
 class CountryItem(BaseModel):
     """A single country in the ``smda.masterdata.country`` list of countries
diff --git a/src/fmu/dataio/_model/root.py b/src/fmu/dataio/_model/root.py
index a5b1cc44d..c89ae15a0 100644
--- a/src/fmu/dataio/_model/root.py
+++ b/src/fmu/dataio/_model/root.py
@@ -280,6 +280,7 @@ def dump() -> dict:
                     "fmu.realization.id",
                     "fmu.realization.name",
                     "fmu.realization.uuid",
+                    "fmu.realization.is_reference",
                     "fmu.workflow",
                     "masterdata",
                     "source",