diff --git a/clients/client-lex-models-v2/src/commands/CreateBotLocaleCommand.ts b/clients/client-lex-models-v2/src/commands/CreateBotLocaleCommand.ts
index 4676e498e757e..9e0544dd95d02 100644
--- a/clients/client-lex-models-v2/src/commands/CreateBotLocaleCommand.ts
+++ b/clients/client-lex-models-v2/src/commands/CreateBotLocaleCommand.ts
@@ -46,7 +46,7 @@ export interface CreateBotLocaleCommandOutput extends CreateBotLocaleResponse, _
  *   nluIntentConfidenceThreshold: Number("double"), // required
  *   voiceSettings: { // VoiceSettings
  *     voiceId: "STRING_VALUE", // required
- *     engine: "standard" || "neural",
+ *     engine: "standard" || "neural" || "long-form" || "generative",
  *   },
  *   generativeAISettings: { // GenerativeAISettings
  *     runtimeSettings: { // RuntimeSettings
@@ -102,7 +102,7 @@ export interface CreateBotLocaleCommandOutput extends CreateBotLocaleResponse, _
  * //   nluIntentConfidenceThreshold: Number("double"),
  * //   voiceSettings: { // VoiceSettings
  * //     voiceId: "STRING_VALUE", // required
- * //     engine: "standard" || "neural",
+ * //     engine: "standard" || "neural" || "long-form" || "generative",
  * //   },
  * //   botLocaleStatus: "Creating" || "Building" || "Built" || "ReadyExpressTesting" || "Failed" || "Deleting" || "NotBuilt" || "Importing" || "Processing",
  * //   creationDateTime: new Date("TIMESTAMP"),
diff --git a/clients/client-lex-models-v2/src/commands/DescribeBotLocaleCommand.ts b/clients/client-lex-models-v2/src/commands/DescribeBotLocaleCommand.ts
index 9ccbce57692c8..20b5c9da34ea7 100644
--- a/clients/client-lex-models-v2/src/commands/DescribeBotLocaleCommand.ts
+++ b/clients/client-lex-models-v2/src/commands/DescribeBotLocaleCommand.ts
@@ -52,7 +52,7 @@ export interface DescribeBotLocaleCommandOutput extends DescribeBotLocaleRespons
  * //   nluIntentConfidenceThreshold: Number("double"),
  * //   voiceSettings: { // VoiceSettings
  * //     voiceId: "STRING_VALUE", // required
- * //     engine: "standard" || "neural",
+ * //     engine: "standard" || "neural" || "long-form" || "generative",
  * //   },
  * //   intentsCount: Number("int"),
  * //   slotTypesCount: Number("int"),
diff --git a/clients/client-lex-models-v2/src/commands/DescribeImportCommand.ts b/clients/client-lex-models-v2/src/commands/DescribeImportCommand.ts
index 0cc576b4df823..0a3015cc6f22a 100644
--- a/clients/client-lex-models-v2/src/commands/DescribeImportCommand.ts
+++ b/clients/client-lex-models-v2/src/commands/DescribeImportCommand.ts
@@ -64,7 +64,7 @@ export interface DescribeImportCommandOutput extends DescribeImportResponse, __M
  * //       nluIntentConfidenceThreshold: Number("double"),
  * //       voiceSettings: { // VoiceSettings
  * //         voiceId: "STRING_VALUE", // required
- * //         engine: "standard" || "neural",
+ * //         engine: "standard" || "neural" || "long-form" || "generative",
  * //       },
  * //     },
  * //     customVocabularyImportSpecification: { // CustomVocabularyImportSpecification
diff --git a/clients/client-lex-models-v2/src/commands/StartImportCommand.ts b/clients/client-lex-models-v2/src/commands/StartImportCommand.ts
index be5aef27d8ef8..d8e0de7320b51 100644
--- a/clients/client-lex-models-v2/src/commands/StartImportCommand.ts
+++ b/clients/client-lex-models-v2/src/commands/StartImportCommand.ts
@@ -60,7 +60,7 @@ export interface StartImportCommandOutput extends StartImportResponse, __Metadat
  *       nluIntentConfidenceThreshold: Number("double"),
  *       voiceSettings: { // VoiceSettings
  *         voiceId: "STRING_VALUE", // required
- *         engine: "standard" || "neural",
+ *         engine: "standard" || "neural" || "long-form" || "generative",
  *       },
  *     },
  *     customVocabularyImportSpecification: { // CustomVocabularyImportSpecification
@@ -116,7 +116,7 @@ export interface StartImportCommandOutput extends StartImportResponse, __Metadat
  * //       nluIntentConfidenceThreshold: Number("double"),
  * //       voiceSettings: { // VoiceSettings
  * //         voiceId: "STRING_VALUE", // required
- * //         engine: "standard" || "neural",
+ * //         engine: "standard" || "neural" || "long-form" || "generative",
  * //       },
  * //     },
  * //     customVocabularyImportSpecification: { // CustomVocabularyImportSpecification
diff --git a/clients/client-lex-models-v2/src/commands/UpdateBotLocaleCommand.ts b/clients/client-lex-models-v2/src/commands/UpdateBotLocaleCommand.ts
index 72374c0798058..c1f270693c5df 100644
--- a/clients/client-lex-models-v2/src/commands/UpdateBotLocaleCommand.ts
+++ b/clients/client-lex-models-v2/src/commands/UpdateBotLocaleCommand.ts
@@ -43,7 +43,7 @@ export interface UpdateBotLocaleCommandOutput extends UpdateBotLocaleResponse, _
  *   nluIntentConfidenceThreshold: Number("double"), // required
  *   voiceSettings: { // VoiceSettings
  *     voiceId: "STRING_VALUE", // required
- *     engine: "standard" || "neural",
+ *     engine: "standard" || "neural" || "long-form" || "generative",
  *   },
  *   generativeAISettings: { // GenerativeAISettings
  *     runtimeSettings: { // RuntimeSettings
@@ -99,7 +99,7 @@ export interface UpdateBotLocaleCommandOutput extends UpdateBotLocaleResponse, _
  * //   nluIntentConfidenceThreshold: Number("double"),
  * //   voiceSettings: { // VoiceSettings
  * //     voiceId: "STRING_VALUE", // required
- * //     engine: "standard" || "neural",
+ * //     engine: "standard" || "neural" || "long-form" || "generative",
  * //   },
  * //   botLocaleStatus: "Creating" || "Building" || "Built" || "ReadyExpressTesting" || "Failed" || "Deleting" || "NotBuilt" || "Importing" || "Processing",
  * //   failureReasons: [ // FailureReasons
diff --git a/clients/client-lex-models-v2/src/models/models_0.ts b/clients/client-lex-models-v2/src/models/models_0.ts
index 8088d13617091..c60748d099f0a 100644
--- a/clients/client-lex-models-v2/src/models/models_0.ts
+++ b/clients/client-lex-models-v2/src/models/models_0.ts
@@ -3547,6 +3547,8 @@ export interface BotLocaleHistoryEvent {
  * @enum
  */
 export const VoiceEngine = {
+  Generative: "generative",
+  LongForm: "long-form",
   Neural: "neural",
   Standard: "standard",
 } as const;
@@ -3559,6 +3561,29 @@ export type VoiceEngine = (typeof VoiceEngine)[keyof typeof VoiceEngine];
 /**
  * <p>Defines settings for using an Amazon Polly voice to communicate with a
  *          user.</p>
+ *          <p>Valid values include:</p>
+ *          <ul>
+ *             <li>
+ *                <p>
+ *                   <code>standard</code>
+ *                </p>
+ *             </li>
+ *             <li>
+ *                <p>
+ *                   <code>neural</code>
+ *                </p>
+ *             </li>
+ *             <li>
+ *                <p>
+ *                   <code>long-form</code>
+ *                </p>
+ *             </li>
+ *             <li>
+ *                <p>
+ *                   <code>generative</code>
+ *                </p>
+ *             </li>
+ *          </ul>
  * @public
  */
 export interface VoiceSettings {
@@ -3647,6 +3672,29 @@ export interface BotLocaleImportSpecification {
   /**
    * <p>Defines settings for using an Amazon Polly voice to communicate with a
    *          user.</p>
+   *          <p>Valid values include:</p>
+   *          <ul>
+   *             <li>
+   *                <p>
+   *                   <code>standard</code>
+   *                </p>
+   *             </li>
+   *             <li>
+   *                <p>
+   *                   <code>neural</code>
+   *                </p>
+   *             </li>
+   *             <li>
+   *                <p>
+   *                   <code>long-form</code>
+   *                </p>
+   *             </li>
+   *             <li>
+   *                <p>
+   *                   <code>generative</code>
+   *                </p>
+   *             </li>
+   *          </ul>
    * @public
    */
   voiceSettings?: VoiceSettings;
diff --git a/codegen/sdk-codegen/aws-models/lex-models-v2.json b/codegen/sdk-codegen/aws-models/lex-models-v2.json
index 450bd58661db9..7f7b662c64e8a 100644
--- a/codegen/sdk-codegen/aws-models/lex-models-v2.json
+++ b/codegen/sdk-codegen/aws-models/lex-models-v2.json
@@ -25023,6 +25023,18 @@
           "traits": {
             "smithy.api#enumValue": "neural"
           }
+        },
+        "LongForm": {
+          "target": "smithy.api#Unit",
+          "traits": {
+            "smithy.api#enumValue": "long-form"
+          }
+        },
+        "Generative": {
+          "target": "smithy.api#Unit",
+          "traits": {
+            "smithy.api#enumValue": "generative"
+          }
         }
       }
     },
@@ -25047,7 +25059,7 @@
         }
       },
       "traits": {
-        "smithy.api#documentation": "<p>Defines settings for using an Amazon Polly voice to communicate with a\n         user.</p>"
+        "smithy.api#documentation": "<p>Defines settings for using an Amazon Polly voice to communicate with a\n         user.</p>\n         <p>Valid values include:</p>\n         <ul>\n            <li>\n               <p>\n                  <code>standard</code>\n               </p>\n            </li>\n            <li>\n               <p>\n                  <code>neural</code>\n               </p>\n            </li>\n            <li>\n               <p>\n                  <code>long-form</code>\n               </p>\n            </li>\n            <li>\n               <p>\n                  <code>generative</code>\n               </p>\n            </li>\n         </ul>"
       }
     },
     "com.amazonaws.lexmodelsv2#WaitAndContinueSpecification": {