diff --git a/specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents/Microsoft.HealthcareApis/HealthcareApis.tsp b/specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents/Microsoft.HealthcareApis/HealthcareApis.tsp
index 0e1dce392dbe..cfec7d1f7015 100644
--- a/specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents/Microsoft.HealthcareApis/HealthcareApis.tsp
+++ b/specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents/Microsoft.HealthcareApis/HealthcareApis.tsp
@@ -1,5 +1,4 @@
 import "@typespec/versioning";
-
 using TypeSpec.Versioning;
 
 /** Describes the schema of the Azure HealthcareApis events published to Azure Event Grid. This corresponds to the Data property of an EventGridEvent. */
@@ -12,13 +11,14 @@ namespace Microsoft.EventGrid.SystemEvents {
     resourceType: HealthcareFhirResourceType;
 
     /** Domain name of FHIR account for this resource. */
-    resourceFhirAccount?: string;
+    resourceFhirAccount: string;
 
     /** Id of HL7 FHIR resource. */
-    resourceFhirId?: string;
+    resourceFhirId: string;
 
     /** VersionId of HL7 FHIR resource. It changes when the resource is created, updated, or deleted(soft-deletion). */
-    resourceVersionId?: int64;
+    @madeRequired(ServiceApiVersions.v2024_01_01)
+    resourceVersionId: int64;
   }
 
   /** Schema of the Data property of an EventGridEvent for a Microsoft.HealthcareApis.FhirResourceUpdated event. */
@@ -28,13 +28,14 @@ namespace Microsoft.EventGrid.SystemEvents {
     resourceType: HealthcareFhirResourceType;
 
     /** Domain name of FHIR account for this resource. */
-    resourceFhirAccount?: string;
+    resourceFhirAccount: string;
 
     /** Id of HL7 FHIR resource. */
-    resourceFhirId?: string;
+    resourceFhirId: string;
 
     /** VersionId of HL7 FHIR resource. It changes when the resource is created, updated, or deleted(soft-deletion). */
-    resourceVersionId?: int64;
+    @madeRequired(ServiceApiVersions.v2024_01_01)
+    resourceVersionId: int64;
   }
 
   /** Schema of the Data property of an EventGridEvent for a Microsoft.HealthcareApis.FhirResourceDeleted event. */
@@ -44,76 +45,80 @@ namespace Microsoft.EventGrid.SystemEvents {
     resourceType: HealthcareFhirResourceType;
 
     /** Domain name of FHIR account for this resource. */
-    resourceFhirAccount?: string;
+    resourceFhirAccount: string;
 
     /** Id of HL7 FHIR resource. */
-    resourceFhirId?: string;
+    resourceFhirId: string;
 
     /** VersionId of HL7 FHIR resource. It changes when the resource is created, updated, or deleted(soft-deletion). */
-    resourceVersionId?: int64;
+    @madeRequired(ServiceApiVersions.v2024_01_01)
+    resourceVersionId: int64;
   }
 
   /** Schema of the Data property of an EventGridEvent for a Microsoft.HealthcareApis.DicomImageCreated event. */
   model HealthcareDicomImageCreatedEventData {
     /** Data partition name */
-    partitionName?: string;
+    partitionName: string;
 
     /** Unique identifier for the Study */
-    imageStudyInstanceUid?: string;
+    imageStudyInstanceUid: string;
 
     /** Unique identifier for the Series */
-    imageSeriesInstanceUid?: string;
+    imageSeriesInstanceUid: string;
 
     /** Unique identifier for the DICOM Image */
-    imageSopInstanceUid?: string;
+    imageSopInstanceUid: string;
 
     /** Domain name of the DICOM account for this image. */
-    serviceHostName?: string;
+    serviceHostName: string;
 
     /** Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation and deletion within the service. */
-    sequenceNumber?: int64;
+    @madeRequired(ServiceApiVersions.v2024_01_01)
+    sequenceNumber: int64;
   }
 
   /** Schema of the Data property of an EventGridEvent for a Microsoft.HealthcareApis.DicomImageDeleted event. */
   model HealthcareDicomImageDeletedEventData {
     /** Data partition name */
-    partitionName?: string;
+    partitionName: string;
 
     /** Unique identifier for the Study */
-    imageStudyInstanceUid?: string;
+    imageStudyInstanceUid: string;
 
     /** Unique identifier for the Series */
-    imageSeriesInstanceUid?: string;
+    imageSeriesInstanceUid: string;
 
     /** Unique identifier for the DICOM Image */
-    imageSopInstanceUid?: string;
+    imageSopInstanceUid: string;
 
     /** Host name of the DICOM account for this image. */
-    serviceHostName?: string;
+    serviceHostName: string;
 
     /** Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation and deletion within the service. */
-    sequenceNumber?: int64;
+    @madeRequired(ServiceApiVersions.v2024_01_01)
+    sequenceNumber: int64;
   }
 
   /** Schema of the Data property of an EventGridEvent for a Microsoft.HealthcareApis.DicomImageUpdated event. */
   model HealthcareDicomImageUpdatedEventData {
     /** Data partition name */
-    partitionName?: string;
+    partitionName: string;
 
     /** Unique identifier for the Study */
-    imageStudyInstanceUid?: string;
+    imageStudyInstanceUid: string;
 
     /** Unique identifier for the Series */
-    imageSeriesInstanceUid?: string;
+    imageSeriesInstanceUid: string;
 
     /** Unique identifier for the DICOM Image */
-    imageSopInstanceUid?: string;
+    imageSopInstanceUid: string;
 
     /** Domain name of the DICOM account for this image. */
-    serviceHostName?: string;
+    serviceHostName: string;
 
     /** Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation, updation and deletion within the service. */
-    sequenceNumber?: int64;
+    @madeRequired(ServiceApiVersions.v2024_01_01)
+    sequenceNumber: int64;
   }
 
   /** Schema of FHIR resource type enumeration. */
diff --git a/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2018-01-01/GeneratedSystemEvents.json b/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2018-01-01/GeneratedSystemEvents.json
index a4f11dfdb108..9ade06e6351f 100644
--- a/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2018-01-01/GeneratedSystemEvents.json
+++ b/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2018-01-01/GeneratedSystemEvents.json
@@ -4280,7 +4280,14 @@
           "format": "int64",
           "description": "Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation and deletion within the service."
         }
-      }
+      },
+      "required": [
+        "partitionName",
+        "imageStudyInstanceUid",
+        "imageSeriesInstanceUid",
+        "imageSopInstanceUid",
+        "serviceHostName"
+      ]
     },
     "HealthcareDicomImageDeletedEventData": {
       "type": "object",
@@ -4311,7 +4318,14 @@
           "format": "int64",
           "description": "Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation and deletion within the service."
         }
-      }
+      },
+      "required": [
+        "partitionName",
+        "imageStudyInstanceUid",
+        "imageSeriesInstanceUid",
+        "imageSopInstanceUid",
+        "serviceHostName"
+      ]
     },
     "HealthcareDicomImageUpdatedEventData": {
       "type": "object",
@@ -4342,7 +4356,14 @@
           "format": "int64",
           "description": "Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation, updation and deletion within the service."
         }
-      }
+      },
+      "required": [
+        "partitionName",
+        "imageStudyInstanceUid",
+        "imageSeriesInstanceUid",
+        "imageSopInstanceUid",
+        "serviceHostName"
+      ]
     },
     "HealthcareFhirResourceCreatedEventData": {
       "type": "object",
@@ -4369,7 +4390,11 @@
           "description": "VersionId of HL7 FHIR resource. It changes when the resource is created, updated, or deleted(soft-deletion).",
           "x-ms-client-name": "FhirResourceVersionId"
         }
-      }
+      },
+      "required": [
+        "resourceFhirAccount",
+        "resourceFhirId"
+      ]
     },
     "HealthcareFhirResourceDeletedEventData": {
       "type": "object",
@@ -4396,7 +4421,11 @@
           "description": "VersionId of HL7 FHIR resource. It changes when the resource is created, updated, or deleted(soft-deletion).",
           "x-ms-client-name": "FhirResourceVersionId"
         }
-      }
+      },
+      "required": [
+        "resourceFhirAccount",
+        "resourceFhirId"
+      ]
     },
     "HealthcareFhirResourceType": {
       "type": "string",
@@ -5401,7 +5430,11 @@
           "description": "VersionId of HL7 FHIR resource. It changes when the resource is created, updated, or deleted(soft-deletion).",
           "x-ms-client-name": "FhirResourceVersionId"
         }
-      }
+      },
+      "required": [
+        "resourceFhirAccount",
+        "resourceFhirId"
+      ]
     },
     "IotHubDeviceConnectedEventData": {
       "type": "object",
diff --git a/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2024-01-01/GeneratedSystemEvents.json b/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2024-01-01/GeneratedSystemEvents.json
index 18f5d2df1652..520cdff08a9b 100644
--- a/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2024-01-01/GeneratedSystemEvents.json
+++ b/specification/eventgrid/data-plane/Microsoft.EventGrid/stable/2024-01-01/GeneratedSystemEvents.json
@@ -4366,7 +4366,15 @@
           "format": "int64",
           "description": "Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation and deletion within the service."
         }
-      }
+      },
+      "required": [
+        "partitionName",
+        "imageStudyInstanceUid",
+        "imageSeriesInstanceUid",
+        "imageSopInstanceUid",
+        "serviceHostName",
+        "sequenceNumber"
+      ]
     },
     "HealthcareDicomImageDeletedEventData": {
       "type": "object",
@@ -4397,7 +4405,15 @@
           "format": "int64",
           "description": "Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation and deletion within the service."
         }
-      }
+      },
+      "required": [
+        "partitionName",
+        "imageStudyInstanceUid",
+        "imageSeriesInstanceUid",
+        "imageSopInstanceUid",
+        "serviceHostName",
+        "sequenceNumber"
+      ]
     },
     "HealthcareDicomImageUpdatedEventData": {
       "type": "object",
@@ -4428,7 +4444,15 @@
           "format": "int64",
           "description": "Sequence number of the DICOM Service within Azure Health Data Services. It is unique for every image creation, updation and deletion within the service."
         }
-      }
+      },
+      "required": [
+        "partitionName",
+        "imageStudyInstanceUid",
+        "imageSeriesInstanceUid",
+        "imageSopInstanceUid",
+        "serviceHostName",
+        "sequenceNumber"
+      ]
     },
     "HealthcareFhirResourceCreatedEventData": {
       "type": "object",
@@ -4457,7 +4481,10 @@
         }
       },
       "required": [
-        "resourceType"
+        "resourceType",
+        "resourceFhirAccount",
+        "resourceFhirId",
+        "resourceVersionId"
       ]
     },
     "HealthcareFhirResourceDeletedEventData": {
@@ -4487,7 +4514,10 @@
         }
       },
       "required": [
-        "resourceType"
+        "resourceType",
+        "resourceFhirAccount",
+        "resourceFhirId",
+        "resourceVersionId"
       ]
     },
     "HealthcareFhirResourceType": {
@@ -5495,7 +5525,10 @@
         }
       },
       "required": [
-        "resourceType"
+        "resourceType",
+        "resourceFhirAccount",
+        "resourceFhirId",
+        "resourceVersionId"
       ]
     },
     "IotHubDeviceConnectedEventData": {