diff --git a/addons/api/addon/models/fragment-host-set.js b/addons/api/addon/models/fragment-host-set.js
new file mode 100644
index 000000000..975d7e1f0
--- /dev/null
+++ b/addons/api/addon/models/fragment-host-set.js
@@ -0,0 +1,16 @@
+import Fragment from 'ember-data-model-fragments/fragment';
+import { attr } from '@ember-data/model';
+
+export default class FragmentHostSetModel extends Fragment {
+
+  // =attributes
+
+  @attr('string', {
+    description: 'ID of the related host set'
+  }) host_set_id;
+
+  @attr('string', {
+    description: 'ID of the catalog to which the host set belongs'
+  }) host_catalog_id;
+
+}
diff --git a/addons/api/addon/models/target.js b/addons/api/addon/models/target.js
index 84b2658dc..66cd0fdfa 100644
--- a/addons/api/addon/models/target.js
+++ b/addons/api/addon/models/target.js
@@ -1,3 +1,39 @@
 import GeneratedTargetModel from '../generated/models/target';
+import { fragmentArray } from 'ember-data-model-fragments/attributes';
 
-export default class TargetModel extends GeneratedTargetModel {}
+export default class TargetModel extends GeneratedTargetModel {
+
+  // =attributes
+
+  @fragmentArray('fragment-host-set', {readOnly: true}) host_sets;
+
+  // =methods
+
+  /**
+   * Saves the `host_set_ids` array on the via the `set-hosts` method.
+   * See serializer and adapter for more information.
+   * @param {object} options
+   * @param {object} options.adapterOptions
+   * @return {Promise}
+   */
+  saveHostSets(options={ adapterOptions: {} }) {
+    const defaultOptions = {
+      adapterOptions: {
+        method: 'set-host-sets',
+        serializeHostSets: true
+      }
+    };
+    // There is no "deep merge" in ES.
+    // All of this nonsense is here to ensure we get
+    // a decent merge of `adapterOptions`.
+    return this.save({
+      ...defaultOptions,
+      ...options,
+      adapterOptions: {
+        ...defaultOptions.adapterOptions,
+        ...options.adapterOptions
+      }
+    });
+  }
+
+}
diff --git a/addons/api/addon/serializers/target.js b/addons/api/addon/serializers/target.js
new file mode 100644
index 000000000..fefaf0fcb
--- /dev/null
+++ b/addons/api/addon/serializers/target.js
@@ -0,0 +1,35 @@
+import ApplicationSerializer from './application';
+
+export default class TargetSerializer extends ApplicationSerializer {
+
+  // =methods
+
+  /**
+   * If `adapterOptions.serializeHostSets` is true, the serialization should
+   * include **only host sets** and the version.  Normally, host sets are not
+   * serialized.
+   * @override
+   * @param {Snapshot} snapshot
+   * @return {object}
+   */
+  serialize(snapshot) {
+    const serializeHostSets = snapshot?.adapterOptions?.serializeHostSets;
+    let serialized = super.serialize(...arguments);
+    if (serializeHostSets) serialized = this.serializeWithHostSets(snapshot);
+    return serialized;
+  }
+
+  /**
+   * Returns a payload containing only the host_set_ids array.
+   * @param {Snapshot} snapshot
+   * @return {object}
+   */
+  serializeWithHostSets(snapshot) {
+    return {
+      version: snapshot.attr('version'),
+      host_set_ids:
+        snapshot.attr('host_sets').map(hostSet => hostSet.attr('host_set_id'))
+    };
+  }
+
+}
diff --git a/addons/api/app/models/fragment-host-set.js b/addons/api/app/models/fragment-host-set.js
new file mode 100644
index 000000000..bd1726680
--- /dev/null
+++ b/addons/api/app/models/fragment-host-set.js
@@ -0,0 +1 @@
+export { default } from 'api/models/fragment-host-set';
diff --git a/addons/api/app/serializers/target.js b/addons/api/app/serializers/target.js
new file mode 100644
index 000000000..6b8e5abe4
--- /dev/null
+++ b/addons/api/app/serializers/target.js
@@ -0,0 +1 @@
+export { default } from 'api/serializers/target';
diff --git a/addons/api/tests/unit/models/fragment-host-set-test.js b/addons/api/tests/unit/models/fragment-host-set-test.js
new file mode 100644
index 000000000..5862a94a3
--- /dev/null
+++ b/addons/api/tests/unit/models/fragment-host-set-test.js
@@ -0,0 +1,13 @@
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+
+module('Unit | Model | fragment host set', function(hooks) {
+  setupTest(hooks);
+
+  // Replace this with your real tests.
+  test('it exists', function(assert) {
+    let store = this.owner.lookup('service:store');
+    let model = store.createRecord('fragment-host-set', {});
+    assert.ok(model);
+  });
+});
diff --git a/addons/api/tests/unit/models/target-test.js b/addons/api/tests/unit/models/target-test.js
index 78fc71e43..a9ae5ca15 100644
--- a/addons/api/tests/unit/models/target-test.js
+++ b/addons/api/tests/unit/models/target-test.js
@@ -1,13 +1,47 @@
 import { module, test } from 'qunit';
 import { setupTest } from 'ember-qunit';
+import setupMirage from 'ember-cli-mirage/test-support/setup-mirage';
 
-module('Unit | Model | target', function(hooks) {
+module('Unit | Model | target', function (hooks) {
   setupTest(hooks);
+  setupMirage(hooks);
 
-  // Replace this with your real tests.
   test('it exists', function(assert) {
     let store = this.owner.lookup('service:store');
     let model = store.createRecord('target', {});
     assert.ok(model);
   });
+
+  test('it has a `saveHostSets` method that targets a specific POST API endpoint and serialization', async function (assert) {
+    assert.expect(1);
+    this.server.post('/v1/scopes/o_1/targets/123abc:set-host-sets', (schema, request) => {
+      const body = JSON.parse(request.requestBody);
+      assert.deepEqual(body, {
+        host_set_ids: ['1', '3'],
+        version: 1
+      });
+    });
+    const store = this.owner.lookup('service:store');
+    store.push({
+      data: {
+        id: '123abc',
+        type: 'target',
+        attributes: {
+          name: 'Target',
+          description: 'Description',
+          host_sets: [
+            { host_set_id: '1', host_catalog_id: '2' },
+            { host_set_id: '3', host_catalog_id: '4' }
+          ],
+          version: 1,
+          scope: {
+            scope_id: 'o_1',
+            type: 'scope'
+          }
+        }
+      }
+    });
+    const model = store.peekRecord('target', '123abc');
+    await model.saveHostSets();
+  });
 });
diff --git a/addons/api/tests/unit/serializers/target-test.js b/addons/api/tests/unit/serializers/target-test.js
new file mode 100644
index 000000000..a3ca9bd69
--- /dev/null
+++ b/addons/api/tests/unit/serializers/target-test.js
@@ -0,0 +1,91 @@
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+
+module('Unit | Serializer | target', function(hooks) {
+  setupTest(hooks);
+
+  test('it serializes targets normally, without host sets', function (assert) {
+    assert.expect(1);
+    const store = this.owner.lookup('service:store');
+    const serializer = store.serializerFor('target');
+    const record = store.createRecord('target', {
+      name: 'User',
+      description: 'Description',
+      host_sets: [
+        { host_set_id: '1', host_catalog_id: '2' },
+        { host_set_id: '3', host_catalog_id: '4' }
+      ],
+      version: 1
+    });
+    const snapshot = record._createSnapshot();
+    snapshot.adapterOptions = {};
+    const serializedRecord = serializer.serialize(snapshot);
+    assert.deepEqual(serializedRecord, {
+      name: 'User',
+      description: 'Description',
+      version: 1,
+      protocol: null
+    });
+
+  });
+
+  test('it serializes only host sets when `adapterOptions.serializeHostSets` is true', function (assert) {
+    assert.expect(1);
+    const store = this.owner.lookup('service:store');
+    const serializer = store.serializerFor('target');
+    const record = store.createRecord('target', {
+      name: 'User',
+      description: 'Description',
+      host_sets: [
+        { host_set_id: '1', host_catalog_id: '2' },
+        { host_set_id: '3', host_catalog_id: '4' }
+      ],
+      version: 1
+    });
+    const snapshot = record._createSnapshot();
+    snapshot.adapterOptions = {
+      serializeHostSets: true
+    };
+    const serializedRecord = serializer.serialize(snapshot);
+    assert.deepEqual(serializedRecord, {
+      host_set_ids: ['1', '3'],
+      version: 1
+    });
+  });
+
+  test('it normalizes records with array fields', function (assert) {
+    assert.expect(1);
+    const store = this.owner.lookup('service:store');
+    const serializer = store.serializerFor('target');
+    const targetModelClass = store.createRecord('target').constructor;
+    const payload = {
+      id: '1',
+      name: 'Target 1',
+      host_sets: [
+        { host_set_id: '1', host_catalog_id: '2' },
+        { host_set_id: '3', host_catalog_id: '4' }
+      ]
+    };
+    const normalized = serializer.normalizeSingleResponse(
+      store,
+      targetModelClass,
+      payload
+    );
+    assert.deepEqual(normalized, {
+      included: [],
+      data: {
+        id: '1',
+        type: 'target',
+        attributes: {
+          name: 'Target 1',
+          host_sets: [
+            { host_set_id: '1', host_catalog_id: '2' },
+            { host_set_id: '3', host_catalog_id: '4' }
+          ]
+        },
+        relationships: {},
+      },
+    });
+  });
+
+});