diff --git a/Bandwidth.Standard.sln b/Bandwidth.Standard.sln
index 1316fab..becd3cf 100644
--- a/Bandwidth.Standard.sln
+++ b/Bandwidth.Standard.sln
@@ -2,7 +2,7 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 14
 VisualStudioVersion = 14.0.25420.1
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bandwidth.Standard", "src\Bandwidth.Standard\Bandwidth.Standard.csproj", "{0D35B09E-2ACC-417E-AE79-F74BE48DFB3F}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bandwidth.Standard", "src\Bandwidth.Standard\Bandwidth.Standard.csproj", "{4B6F94E7-BD68-40BD-AE9F-6E0A2DABA2E1}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bandwidth.Standard.Test", "src\Bandwidth.Standard.Test\Bandwidth.Standard.Test.csproj", "{19F1DEBC-DE5E-4517-8062-F000CD499087}"
 EndProject
@@ -12,10 +12,10 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{0D35B09E-2ACC-417E-AE79-F74BE48DFB3F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{0D35B09E-2ACC-417E-AE79-F74BE48DFB3F}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{0D35B09E-2ACC-417E-AE79-F74BE48DFB3F}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{0D35B09E-2ACC-417E-AE79-F74BE48DFB3F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4B6F94E7-BD68-40BD-AE9F-6E0A2DABA2E1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4B6F94E7-BD68-40BD-AE9F-6E0A2DABA2E1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4B6F94E7-BD68-40BD-AE9F-6E0A2DABA2E1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4B6F94E7-BD68-40BD-AE9F-6E0A2DABA2E1}.Release|Any CPU.Build.0 = Release|Any CPU
 		{19F1DEBC-DE5E-4517-8062-F000CD499087}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{19F1DEBC-DE5E-4517-8062-F000CD499087}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{19F1DEBC-DE5E-4517-8062-F000CD499087}.Release|Any CPU.ActiveCfg = Release|Any CPU
diff --git a/api/openapi.yaml b/api/openapi.yaml
index 760eef8..570ecc6 100644
--- a/api/openapi.yaml
+++ b/api/openapi.yaml
@@ -6513,7 +6513,6 @@ components:
       - id
       - media
       - owner
-      - priority
       - segmentCount
       - text
       - time
@@ -6685,7 +6684,6 @@ components:
       - from
       - id
       - owner
-      - priority
       - segmentCount
       - tag
       - text
diff --git a/bandwidth.yml b/bandwidth.yml
index 5362a7c..c4b1fb2 100644
--- a/bandwidth.yml
+++ b/bandwidth.yml
@@ -1862,7 +1862,6 @@ components:
         - from
         - text
         - media
-        - priority
     messageDeliveredCallback:
       description: Message Delivered Callback
       type: object
@@ -2035,7 +2034,6 @@ components:
         - from
         - text
         - tag
-        - priority
     callbackMethodEnum:
       type: string
       nullable: true
diff --git a/docs/MessageFailedCallbackMessage.md b/docs/MessageFailedCallbackMessage.md
index 46c6205..91ab761 100644
--- a/docs/MessageFailedCallbackMessage.md
+++ b/docs/MessageFailedCallbackMessage.md
@@ -16,7 +16,7 @@ Name | Type | Description | Notes
 **Text** | **string** |  | 
 **Tag** | **string** |  | 
 **Media** | **List<string>** |  | [optional] 
-**Priority** | **PriorityEnum** |  | 
+**Priority** | **PriorityEnum** |  | [optional] 
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
 
diff --git a/docs/MessageSendingCallbackMessage.md b/docs/MessageSendingCallbackMessage.md
index 3ad04cd..3724834 100644
--- a/docs/MessageSendingCallbackMessage.md
+++ b/docs/MessageSendingCallbackMessage.md
@@ -16,7 +16,7 @@ Name | Type | Description | Notes
 **Text** | **string** |  | 
 **Tag** | **string** |  | [optional] 
 **Media** | **List<string>** |  | 
-**Priority** | **PriorityEnum** |  | 
+**Priority** | **PriorityEnum** |  | [optional] 
 
 [[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
 
diff --git a/src/Bandwidth.Standard/Model/MessageFailedCallbackMessage.cs b/src/Bandwidth.Standard/Model/MessageFailedCallbackMessage.cs
index f8ddebf..d5f1691 100644
--- a/src/Bandwidth.Standard/Model/MessageFailedCallbackMessage.cs
+++ b/src/Bandwidth.Standard/Model/MessageFailedCallbackMessage.cs
@@ -42,8 +42,8 @@ public partial class MessageFailedCallbackMessage : IValidatableObject
         /// <summary>
         /// Gets or Sets Priority
         /// </summary>
-        [DataMember(Name = "priority", IsRequired = true, EmitDefaultValue = true)]
-        public PriorityEnum Priority { get; set; }
+        [DataMember(Name = "priority", EmitDefaultValue = false)]
+        public PriorityEnum? Priority { get; set; }
         /// <summary>
         /// Initializes a new instance of the <see cref="MessageFailedCallbackMessage" /> class.
         /// </summary>
@@ -63,8 +63,8 @@ protected MessageFailedCallbackMessage() { }
         /// <param name="text">text (required).</param>
         /// <param name="tag">tag (required).</param>
         /// <param name="media">media.</param>
-        /// <param name="priority">priority (required).</param>
-        public MessageFailedCallbackMessage(string id = default(string), string owner = default(string), string applicationId = default(string), DateTime time = default(DateTime), int segmentCount = default(int), MessageDirectionEnum direction = default(MessageDirectionEnum), List<string> to = default(List<string>), string from = default(string), string text = default(string), string tag = default(string), List<string> media = default(List<string>), PriorityEnum priority = default(PriorityEnum))
+        /// <param name="priority">priority.</param>
+        public MessageFailedCallbackMessage(string id = default(string), string owner = default(string), string applicationId = default(string), DateTime time = default(DateTime), int segmentCount = default(int), MessageDirectionEnum direction = default(MessageDirectionEnum), List<string> to = default(List<string>), string from = default(string), string text = default(string), string tag = default(string), List<string> media = default(List<string>), PriorityEnum? priority = default(PriorityEnum?))
         {
             // to ensure "id" is required (not null)
             if (id == null)
@@ -111,8 +111,8 @@ protected MessageFailedCallbackMessage() { }
                 throw new ArgumentNullException("tag is a required property for MessageFailedCallbackMessage and cannot be null");
             }
             this.Tag = tag;
-            this.Priority = priority;
             this.Media = media;
+            this.Priority = priority;
         }
 
         /// <summary>
diff --git a/src/Bandwidth.Standard/Model/MessageSendingCallbackMessage.cs b/src/Bandwidth.Standard/Model/MessageSendingCallbackMessage.cs
index afbae6f..bf0ea7f 100644
--- a/src/Bandwidth.Standard/Model/MessageSendingCallbackMessage.cs
+++ b/src/Bandwidth.Standard/Model/MessageSendingCallbackMessage.cs
@@ -42,8 +42,8 @@ public partial class MessageSendingCallbackMessage : IValidatableObject
         /// <summary>
         /// Gets or Sets Priority
         /// </summary>
-        [DataMember(Name = "priority", IsRequired = true, EmitDefaultValue = true)]
-        public PriorityEnum Priority { get; set; }
+        [DataMember(Name = "priority", EmitDefaultValue = false)]
+        public PriorityEnum? Priority { get; set; }
         /// <summary>
         /// Initializes a new instance of the <see cref="MessageSendingCallbackMessage" /> class.
         /// </summary>
@@ -63,8 +63,8 @@ protected MessageSendingCallbackMessage() { }
         /// <param name="text">text (required).</param>
         /// <param name="tag">tag.</param>
         /// <param name="media">media (required).</param>
-        /// <param name="priority">priority (required).</param>
-        public MessageSendingCallbackMessage(string id = default(string), string owner = default(string), string applicationId = default(string), DateTime time = default(DateTime), int segmentCount = default(int), MessageDirectionEnum direction = default(MessageDirectionEnum), List<string> to = default(List<string>), string from = default(string), string text = default(string), string tag = default(string), List<string> media = default(List<string>), PriorityEnum priority = default(PriorityEnum))
+        /// <param name="priority">priority.</param>
+        public MessageSendingCallbackMessage(string id = default(string), string owner = default(string), string applicationId = default(string), DateTime time = default(DateTime), int segmentCount = default(int), MessageDirectionEnum direction = default(MessageDirectionEnum), List<string> to = default(List<string>), string from = default(string), string text = default(string), string tag = default(string), List<string> media = default(List<string>), PriorityEnum? priority = default(PriorityEnum?))
         {
             // to ensure "id" is required (not null)
             if (id == null)
@@ -111,8 +111,8 @@ protected MessageSendingCallbackMessage() { }
                 throw new ArgumentNullException("media is a required property for MessageSendingCallbackMessage and cannot be null");
             }
             this.Media = media;
-            this.Priority = priority;
             this.Tag = tag;
+            this.Priority = priority;
         }
 
         /// <summary>