diff --git a/common/src/main/java/org/opensearch/ml/common/MLModelGroup.java b/common/src/main/java/org/opensearch/ml/common/MLModelGroup.java
index 6fad6433ff..3a060910e0 100644
--- a/common/src/main/java/org/opensearch/ml/common/MLModelGroup.java
+++ b/common/src/main/java/org/opensearch/ml/common/MLModelGroup.java
@@ -10,6 +10,7 @@
 import lombok.Setter;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.common.util.CollectionUtils;
 import org.opensearch.commons.authuser.User;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -57,6 +58,9 @@ public MLModelGroup(String name, String description, int latestVersion,
                         String modelGroupId,
                         Instant createdTime,
                         Instant lastUpdatedTime) {
+        if (name == null) {
+            throw new IllegalArgumentException("model group name is null");
+        }
         this.name = name;
         this.description = description;
         this.latestVersion = latestVersion;
@@ -73,7 +77,9 @@ public MLModelGroup(StreamInput input) throws IOException{
         name = input.readString();
         description = input.readOptionalString();
         latestVersion = input.readInt();
-        backendRoles = input.readOptionalStringList();
+        if (input.readBoolean()) {
+            backendRoles = input.readStringList();
+        }
         if (input.readBoolean()) {
             this.owner = new User(input);
         } else {
@@ -89,8 +95,14 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeString(name);
         out.writeOptionalString(description);
         out.writeInt(latestVersion);
-        out.writeStringCollection(backendRoles);
+        if (!CollectionUtils.isEmpty(backendRoles)) {
+            out.writeBoolean(true);
+            out.writeStringCollection(backendRoles);
+        } else {
+            out.writeBoolean(false);
+        }
         if (owner != null) {
+            out.writeBoolean(true);
             owner.writeTo(out);
         } else {
             out.writeBoolean(false);
@@ -109,7 +121,7 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         if (description != null) {
             builder.field(DESCRIPTION_FIELD, description);
         }
-        if (backendRoles != null) {
+        if (!CollectionUtils.isEmpty(backendRoles)) {
             builder.field(BACKEND_ROLES_FIELD, backendRoles);
         }
         if (owner != null) {
@@ -134,8 +146,8 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
     public static MLModelGroup parse(XContentParser parser) throws IOException {
         String name = null;
         String description = null;
-        List<String> backendRoles = new ArrayList<>();
-        Integer latestVersion = null;
+        List<String> backendRoles = null;
+        int latestVersion = 0;
         User owner = null;
         String access = null;
         String modelGroupId = null;
@@ -155,6 +167,7 @@ public static MLModelGroup parse(XContentParser parser) throws IOException {
                     description = parser.text();
                     break;
                 case BACKEND_ROLES_FIELD:
+                    backendRoles = new ArrayList<>();
                     ensureExpectedToken(XContentParser.Token.START_ARRAY, parser.currentToken(), parser);
                     while (parser.nextToken() != XContentParser.Token.END_ARRAY) {
                         backendRoles.add(parser.text());
diff --git a/common/src/test/java/org/opensearch/ml/common/MLModelGroupTest.java b/common/src/test/java/org/opensearch/ml/common/MLModelGroupTest.java
new file mode 100644
index 0000000000..da8048b1cc
--- /dev/null
+++ b/common/src/test/java/org/opensearch/ml/common/MLModelGroupTest.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.ml.common;
+
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.commons.authuser.User;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.core.xcontent.XContentBuilder;
+import org.opensearch.core.xcontent.XContentParser;
+import org.opensearch.search.SearchModule;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+
+public class MLModelGroupTest {
+
+    @Rule
+    public ExpectedException exceptionRule = ExpectedException.none();
+
+    @Test
+    public void toXContent_NullName() {
+        exceptionRule.expect(IllegalArgumentException.class);
+        exceptionRule.expectMessage("model group name is null");
+
+        MLModelGroup.builder().build();
+    }
+
+    @Test
+    public void toXContent_Empty() throws IOException {
+        MLModelGroup modelGroup = MLModelGroup.builder().name("test").build();
+        XContentBuilder builder = XContentBuilder.builder(XContentType.JSON.xContent());
+        modelGroup.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        String content = TestHelper.xContentBuilderToString(builder);
+        Assert.assertEquals("{\"name\":\"test\",\"latest_version\":0}", content);
+    }
+
+    @Test
+    public void toXContent() throws IOException {
+        MLModelGroup modelGroup = MLModelGroup.builder()
+                .name("test")
+                .description("this is test group")
+                .latestVersion(1)
+                .backendRoles(Arrays.asList("role1", "role2"))
+                .owner(new User())
+                .access(AccessMode.PUBLIC.name())
+                .build();
+        XContentBuilder builder = XContentBuilder.builder(XContentType.JSON.xContent());
+        modelGroup.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        String content = TestHelper.xContentBuilderToString(builder);
+        Assert.assertEquals("{\"name\":\"test\",\"latest_version\":1,\"description\":\"this is test group\"," +
+                "\"backend_roles\":[\"role1\",\"role2\"]," +
+                "\"owner\":{\"name\":\"\",\"backend_roles\":[],\"roles\":[],\"custom_attribute_names\":[],\"user_requested_tenant\":null}," +
+                "\"access\":\"PUBLIC\"}", content);
+    }
+
+    @Test
+    public void parse() throws IOException {
+        String jsonStr = "{\"name\":\"test\",\"latest_version\":1,\"description\":\"this is test group\"," +
+                "\"backend_roles\":[\"role1\",\"role2\"]," +
+                "\"owner\":{\"name\":\"\",\"backend_roles\":[],\"roles\":[],\"custom_attribute_names\":[],\"user_requested_tenant\":null}," +
+                "\"access\":\"PUBLIC\"}";
+        XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(new SearchModule(Settings.EMPTY,
+                Collections.emptyList()).getNamedXContents()), null, jsonStr);
+        parser.nextToken();
+        MLModelGroup modelGroup = MLModelGroup.parse(parser);
+        Assert.assertEquals("test", modelGroup.getName());
+        Assert.assertEquals("this is test group", modelGroup.getDescription());
+        Assert.assertEquals("PUBLIC", modelGroup.getAccess());
+        Assert.assertEquals(2, modelGroup.getBackendRoles().size());
+        Assert.assertEquals("role1", modelGroup.getBackendRoles().get(0));
+        Assert.assertEquals("role2", modelGroup.getBackendRoles().get(1));
+    }
+
+    @Test
+    public void parse_Empty() throws IOException {
+        String jsonStr = "{\"name\":\"test\"}";
+        XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(new SearchModule(Settings.EMPTY,
+                Collections.emptyList()).getNamedXContents()), null, jsonStr);
+        parser.nextToken();
+        MLModelGroup modelGroup = MLModelGroup.parse(parser);
+        Assert.assertEquals("test", modelGroup.getName());
+        Assert.assertNull(modelGroup.getBackendRoles());
+        Assert.assertNull(modelGroup.getAccess());
+        Assert.assertNull(modelGroup.getOwner());
+    }
+
+    @Test
+    public void writeTo() throws IOException {
+        MLModelGroup originalModelGroup = MLModelGroup.builder()
+                .name("test")
+                .description("this is test group")
+                .latestVersion(1)
+                .backendRoles(Arrays.asList("role1", "role2"))
+                .owner(new User())
+                .access(AccessMode.PUBLIC.name())
+                .build();
+
+        BytesStreamOutput output = new BytesStreamOutput();
+        originalModelGroup.writeTo(output);
+        MLModelGroup modelGroup = new MLModelGroup(output.bytes().streamInput());
+        Assert.assertEquals("test", modelGroup.getName());
+        Assert.assertEquals("this is test group", modelGroup.getDescription());
+        Assert.assertEquals("PUBLIC", modelGroup.getAccess());
+        Assert.assertEquals(2, modelGroup.getBackendRoles().size());
+        Assert.assertEquals("role1", modelGroup.getBackendRoles().get(0));
+        Assert.assertEquals("role2", modelGroup.getBackendRoles().get(1));
+    }
+
+    @Test
+    public void writeTo_Empty() throws IOException {
+        MLModelGroup originalModelGroup = MLModelGroup.builder().name("test").build();
+
+        BytesStreamOutput output = new BytesStreamOutput();
+        originalModelGroup.writeTo(output);
+        MLModelGroup modelGroup = new MLModelGroup(output.bytes().streamInput());
+        Assert.assertEquals("test", modelGroup.getName());
+        Assert.assertNull(modelGroup.getBackendRoles());
+        Assert.assertNull(modelGroup.getAccess());
+        Assert.assertNull(modelGroup.getOwner());
+    }
+}
diff --git a/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java b/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java
index eeb00c1fd0..a55ef27ead 100644
--- a/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java
+++ b/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java
@@ -193,7 +193,9 @@ public void validateUniqueModelGroupName(String name, ActionListener<Boolean> li
     }
 
     private void validateSecurityDisabledOrModelAccessControlDisabled(MLRegisterModelGroupInput input) {
-        if (input.getModelAccessMode() != null || input.getIsAddAllBackendRoles() != null || input.getBackendRoles() != null) {
+        if (input.getModelAccessMode() != null
+            || input.getIsAddAllBackendRoles() != null
+            || !CollectionUtils.isEmpty(input.getBackendRoles())) {
             throw new IllegalArgumentException(
                 "You cannot specify model access control parameters because the Security plugin or model access control is disabled on your cluster."
             );
diff --git a/plugin/src/test/java/org/opensearch/ml/helper/ModelAccessControlHelperTests.java b/plugin/src/test/java/org/opensearch/ml/helper/ModelAccessControlHelperTests.java
index 17b8725620..bf73addf04 100644
--- a/plugin/src/test/java/org/opensearch/ml/helper/ModelAccessControlHelperTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/helper/ModelAccessControlHelperTests.java
@@ -199,8 +199,12 @@ public void test_IsOwner() {
     public void test_IsUserHasBackendRole() {
         User user = User.parse("owner|IT,HR|all_access");
         MLModelGroupBuilder builder = MLModelGroup.builder();
-        assertTrue(modelAccessControlHelper.isUserHasBackendRole(null, builder.access(AccessMode.PUBLIC.getValue()).build()));
-        assertFalse(modelAccessControlHelper.isUserHasBackendRole(null, builder.access(AccessMode.PRIVATE.getValue()).build()));
+        assertTrue(
+            modelAccessControlHelper.isUserHasBackendRole(null, builder.name("test_group").access(AccessMode.PUBLIC.getValue()).build())
+        );
+        assertFalse(
+            modelAccessControlHelper.isUserHasBackendRole(null, builder.name("test_group").access(AccessMode.PRIVATE.getValue()).build())
+        );
         assertTrue(
             modelAccessControlHelper
                 .isUserHasBackendRole(
@@ -218,9 +222,13 @@ public void test_IsOwnerStillHasPermission() {
         User userLostAccess = User.parse("owner|Finance|myTenant");
         assertTrue(modelAccessControlHelper.isOwnerStillHasPermission(null, null));
         MLModelGroupBuilder builder = MLModelGroup.builder();
-        assertTrue(modelAccessControlHelper.isOwnerStillHasPermission(user, builder.access(AccessMode.PUBLIC.getValue()).build()));
         assertTrue(
-            modelAccessControlHelper.isOwnerStillHasPermission(user, builder.access(AccessMode.PRIVATE.getValue()).owner(owner).build())
+            modelAccessControlHelper
+                .isOwnerStillHasPermission(user, builder.name("test_group").access(AccessMode.PUBLIC.getValue()).build())
+        );
+        assertTrue(
+            modelAccessControlHelper
+                .isOwnerStillHasPermission(user, builder.name("test_group").access(AccessMode.PRIVATE.getValue()).owner(owner).build())
         );
         assertFalse(
             modelAccessControlHelper