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..952009d097e6 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 +11,13 @@ 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;
+    resourceVersionId: int64;
   }
 
   /** Schema of the Data property of an EventGridEvent for a Microsoft.HealthcareApis.FhirResourceUpdated event. */
@@ -28,13 +27,14 @@ 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 +44,80 @@ 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 48945635b761..66d66e220b7a 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
@@ -4232,7 +4232,14 @@
           "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",
@@ -4263,7 +4270,14 @@
           "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",
@@ -4294,7 +4308,14 @@
           "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",
@@ -4321,7 +4342,12 @@
           "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",
+        "resourceVersionId"
+      ]
     },
     "HealthcareFhirResourceDeletedEventData": {
       "type": "object",
@@ -4348,7 +4374,11 @@
           "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",
@@ -5353,7 +5383,11 @@
           "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 36bd7e604627..40d76d57e9c4 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
@@ -4321,7 +4321,15 @@
           "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",
@@ -4352,7 +4360,15 @@
           "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",
@@ -4383,7 +4399,15 @@
           "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",
@@ -4412,7 +4436,10 @@
         }
       },
       "required": [
-        "resourceType"
+        "resourceType",
+        "resourceFhirAccount",
+        "resourceFhirId",
+        "resourceVersionId"
       ]
     },
     "HealthcareFhirResourceDeletedEventData": {
@@ -4442,7 +4469,10 @@
         }
       },
       "required": [
-        "resourceType"
+        "resourceType",
+        "resourceFhirAccount",
+        "resourceFhirId",
+        "resourceVersionId"
       ]
     },
     "HealthcareFhirResourceType": {
@@ -5450,7 +5480,10 @@
         }
       },
       "required": [
-        "resourceType"
+        "resourceType",
+        "resourceFhirAccount",
+        "resourceFhirId",
+        "resourceVersionId"
       ]
     },
     "IotHubDeviceConnectedEventData": {