diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index 45ed317..3d1da91 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -20,6 +20,7 @@
 import static android.net.NetworkRequest.Type.BACKGROUND_REQUEST;
 import static android.net.NetworkRequest.Type.LISTEN;
 import static android.net.NetworkRequest.Type.REQUEST;
+import static android.net.NetworkRequest.Type.TRACK_BEST;
 import static android.net.NetworkRequest.Type.TRACK_DEFAULT;
 import static android.net.NetworkRequest.Type.TRACK_SYSTEM_DEFAULT;
 import static android.net.QosCallback.QosCallbackRegistrationException;
@@ -4190,6 +4191,18 @@
     }
 
     /**
+     * @hide
+     */
+    // TODO: Make it public api.
+    @SuppressLint("ExecutorRegistration")
+    public void registerBestMatchingNetworkCallback(@NonNull NetworkRequest request,
+            @NonNull NetworkCallback networkCallback, @NonNull Handler handler) {
+        final NetworkCapabilities nc = request.networkCapabilities;
+        final CallbackHandler cbHandler = new CallbackHandler(handler);
+        sendRequestForNetwork(nc, networkCallback, 0, TRACK_BEST, TYPE_NONE, cbHandler);
+    }
+
+    /**
      * Requests bandwidth update for a given {@link Network} and returns whether the update request
      * is accepted by ConnectivityService. Once accepted, ConnectivityService will poll underlying
      * network connection for updated bandwidth information. The caller will be notified via
diff --git a/framework/src/android/net/NetworkRequest.java b/framework/src/android/net/NetworkRequest.java
index b4a651c..59b539a 100644
--- a/framework/src/android/net/NetworkRequest.java
+++ b/framework/src/android/net/NetworkRequest.java
@@ -113,6 +113,10 @@
      *       for the network (if any) that satisfies the default Internet
      *       request.
      *
+     *     - TRACK_BEST, which causes the framework to send callbacks about
+     *       the single, highest scoring current network (if any) that matches
+     *       the specified NetworkCapabilities.
+     *
      *     - BACKGROUND_REQUEST, like REQUEST but does not cause any networks
      *       to retain the NET_CAPABILITY_FOREGROUND capability. A network with
      *       no foreground requests is in the background. A network that has
@@ -135,6 +139,7 @@
         REQUEST,
         BACKGROUND_REQUEST,
         TRACK_SYSTEM_DEFAULT,
+        TRACK_BEST,
     };
 
     /**
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 78853c7..3d55c16 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -5547,6 +5547,8 @@
                 //  request if the app changes network state. http://b/29964605
                 enforceMeteredApnPolicy(networkCapabilities);
                 break;
+            case TRACK_BEST:
+                throw new UnsupportedOperationException("Not implemented yet");
             default:
                 throw new IllegalArgumentException("Unsupported request type " + reqType);
         }
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 15a7b91..d960cc7 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -11026,4 +11026,12 @@
         verifyNoNetwork();
         mCm.unregisterNetworkCallback(cellCb);
     }
-}
\ No newline at end of file
+
+    @Test
+    public void testRegisterBestMatchingNetworkCallback() throws Exception {
+        final NetworkRequest request = new NetworkRequest.Builder().build();
+        assertThrows(UnsupportedOperationException.class,
+                () -> mCm.registerBestMatchingNetworkCallback(request, new NetworkCallback(),
+                        mCsHandlerThread.getThreadHandler()));
+    }
+}