diff --git a/addons/api/addon/generated/models/managed-group.js b/addons/api/addon/generated/models/managed-group.js
index 279ee3898..d6502eee6 100644
--- a/addons/api/addon/generated/models/managed-group.js
+++ b/addons/api/addon/generated/models/managed-group.js
@@ -44,11 +44,4 @@ export default class GeneratedManagedGroupModel extends BaseModel {
       'The ID of the Auth Method that is associated with this ManagedGroup',
   })
   auth_method_id;
-
-  @attr('array', {
-    description:
-      'The IDs of the current set of members (accounts) that are associated with this ManagedGroup.',
-    readOnly: true,
-  })
-  member_ids;
 }
diff --git a/addons/api/addon/models/managed-group.js b/addons/api/addon/models/managed-group.js
index 8a72a15b9..426807de2 100644
--- a/addons/api/addon/models/managed-group.js
+++ b/addons/api/addon/models/managed-group.js
@@ -1,12 +1,21 @@
 import GeneratedManagedGroupModel from '../generated/models/managed-group';
 import { attr } from '@ember-data/model';
 import { fragment } from 'ember-data-model-fragments/attributes';
+import { A } from '@ember/array';
 
 export default class ManagedGroupModel extends GeneratedManagedGroupModel {
-  // =error attributes
-  @attr('string', { readOnly: true }) filter;
-
   // =attributes
+  /**
+   * Members is read-only under normal circumstances.  But members can
+   * be persisted via calls to `addMembers()` or `removeMembers()`.
+   */
+  @attr({
+    readOnly: true,
+    defaultValue: () => A(),
+    emptyArrayIfMissing: true,
+  })
+  member_ids;
+
   @fragment('fragment-managed-group-attributes', { defaultValue: {} })
   attributes;
 }
diff --git a/addons/api/addon/serializers/fragment-managed-group-attributes.js b/addons/api/addon/serializers/fragment-managed-group-attributes.js
index c250ec4df..230358a20 100644
--- a/addons/api/addon/serializers/fragment-managed-group-attributes.js
+++ b/addons/api/addon/serializers/fragment-managed-group-attributes.js
@@ -12,10 +12,16 @@ export default class FragmentManagedGroupAttributesSerializer extends JSONSerial
    * @param {Object} attribute
    */
   serializeAttribute(snapshot, json, key, attribute) {
-    const { type } = attribute;
+    const { type, options } = attribute;
     let value = super.serializeAttribute(...arguments);
     // Convert empty string to null.
     if (type === 'string' && json[key] === '') json[key] = null;
+    // Do not serialize read-only attributes.
+    if (options.readOnly) delete json[key];
+    // Version is sent only if it has a non-nullish value
+    if (key === 'version') {
+      if (json[key] === null || json[key] === undefined) delete json[key];
+    }
     return value;
   }
 }
diff --git a/addons/api/tests/unit/serializers/managed-group-test.js b/addons/api/tests/unit/serializers/managed-group-test.js
index 561cddb61..4fb7e5a2b 100644
--- a/addons/api/tests/unit/serializers/managed-group-test.js
+++ b/addons/api/tests/unit/serializers/managed-group-test.js
@@ -60,6 +60,41 @@ module('Unit | Serializer | Managed group', function (hooks) {
     });
   });
 
+  test('it does not serialize version when it has null or undefined value', function (assert) {
+    assert.expect(1);
+    const store = this.owner.lookup('service:store');
+    const serializer = store.serializerFor('managed-group');
+    store.push({
+      data: {
+        id: '1',
+        type: 'managed-group',
+        attributes: {
+          name: 'Group Test',
+          description: 'Description for the test',
+          member_ids: ['1', '2'],
+          version: undefined,
+          auth_method_id: '1234',
+          type: 'oidc',
+          attributes: {
+            filter: 'key=value',
+          },
+        },
+      },
+    });
+    const record = store.peekRecord('managed-group', '1');
+    const snapshot = record._createSnapshot();
+    const serializedRecord = serializer.serialize(snapshot);
+    assert.deepEqual(serializedRecord, {
+      name: 'Group Test',
+      description: 'Description for the test',
+      auth_method_id: '1234',
+      type: 'oidc',
+      attributes: {
+        filter: 'key=value',
+      },
+    });
+  });
+
   test('it does not serialize readOnly attributes', function (assert) {
     assert.expect(1);
     const store = this.owner.lookup('service:store');