diff --git a/clients/client-omics/src/commands/CreateMultipartReadSetUploadCommand.ts b/clients/client-omics/src/commands/CreateMultipartReadSetUploadCommand.ts
index 595bb21e9fc7..75c798e58ea9 100644
--- a/clients/client-omics/src/commands/CreateMultipartReadSetUploadCommand.ts
+++ b/clients/client-omics/src/commands/CreateMultipartReadSetUploadCommand.ts
@@ -58,7 +58,7 @@ export interface CreateMultipartReadSetUploadCommandOutput
  *   subjectId: "STRING_VALUE", // required
  *   sampleId: "STRING_VALUE", // required
  *   generatedFrom: "STRING_VALUE",
- *   referenceArn: "STRING_VALUE", // required
+ *   referenceArn: "STRING_VALUE",
  *   name: "STRING_VALUE", // required
  *   description: "STRING_VALUE",
  *   tags: { // TagMap
diff --git a/clients/client-omics/src/commands/StartReadSetImportJobCommand.ts b/clients/client-omics/src/commands/StartReadSetImportJobCommand.ts
index cd9f56ed65a3..5ebcbc2a858a 100644
--- a/clients/client-omics/src/commands/StartReadSetImportJobCommand.ts
+++ b/clients/client-omics/src/commands/StartReadSetImportJobCommand.ts
@@ -58,7 +58,7 @@ export interface StartReadSetImportJobCommandOutput extends StartReadSetImportJo
  *       subjectId: "STRING_VALUE", // required
  *       sampleId: "STRING_VALUE", // required
  *       generatedFrom: "STRING_VALUE",
- *       referenceArn: "STRING_VALUE", // required
+ *       referenceArn: "STRING_VALUE",
  *       name: "STRING_VALUE",
  *       description: "STRING_VALUE",
  *       tags: { // TagMap
diff --git a/clients/client-omics/src/models/models_0.ts b/clients/client-omics/src/models/models_0.ts
index f4f742e3b215..5c1853305fbe 100644
--- a/clients/client-omics/src/models/models_0.ts
+++ b/clients/client-omics/src/models/models_0.ts
@@ -2524,6 +2524,7 @@ export const FileType = {
   BAM: "BAM",
   CRAM: "CRAM",
   FASTQ: "FASTQ",
+  UBAM: "UBAM",
 } as const;
 
 /**
@@ -2589,7 +2590,7 @@ export interface CreateMultipartReadSetUploadRequest {
    *       The ARN of the reference.
    *     </p>
    */
-  referenceArn: string | undefined;
+  referenceArn?: string;
 
   /**
    * @public
@@ -8027,7 +8028,7 @@ export interface StartReadSetImportJobSourceItem {
    * @public
    * <p>The source's reference ARN.</p>
    */
-  referenceArn: string | undefined;
+  referenceArn?: string;
 
   /**
    * @public
diff --git a/codegen/sdk-codegen/aws-models/omics.json b/codegen/sdk-codegen/aws-models/omics.json
index 4642b1ab0852..84920f409e1a 100644
--- a/codegen/sdk-codegen/aws-models/omics.json
+++ b/codegen/sdk-codegen/aws-models/omics.json
@@ -1620,8 +1620,7 @@
         "referenceArn": {
           "target": "com.amazonaws.omics#ReferenceArn",
           "traits": {
-            "smithy.api#documentation": "<p>\n      The ARN of the reference.\n    </p>",
-            "smithy.api#required": {}
+            "smithy.api#documentation": "<p>\n      The ARN of the reference.\n    </p>"
           }
         },
         "name": {
@@ -3559,6 +3558,10 @@
           {
             "value": "CRAM",
             "name": "CRAM"
+          },
+          {
+            "value": "UBAM",
+            "name": "UBAM"
           }
         ]
       }
@@ -11443,7 +11446,7 @@
           }
         },
         "referenceArn": {
-          "target": "com.amazonaws.omics#ReferenceArn",
+          "target": "com.amazonaws.omics#ReferenceArnFilter",
           "traits": {
             "smithy.api#documentation": "<p>A genome reference ARN to filter on.</p>"
           }
@@ -11899,6 +11902,16 @@
         "smithy.api#pattern": "^arn:.+$"
       }
     },
+    "com.amazonaws.omics#ReferenceArnFilter": {
+      "type": "string",
+      "traits": {
+        "smithy.api#length": {
+          "min": 0,
+          "max": 127
+        },
+        "smithy.api#pattern": "^$|^arn:.+$"
+      }
+    },
     "com.amazonaws.omics#ReferenceDescription": {
       "type": "string",
       "traits": {
@@ -14122,8 +14135,7 @@
         "referenceArn": {
           "target": "com.amazonaws.omics#ReferenceArn",
           "traits": {
-            "smithy.api#documentation": "<p>The source's reference ARN.</p>",
-            "smithy.api#required": {}
+            "smithy.api#documentation": "<p>The source's reference ARN.</p>"
           }
         },
         "name": {