diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index f888da5..b3f0b2c 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -1427,7 +1427,7 @@
         public CarrierPrivilegeAuthenticator makeCarrierPrivilegeAuthenticator(
                 @NonNull final Context context, @NonNull final TelephonyManager tm) {
             if (isAtLeastT()) {
-                return new CarrierPrivilegeAuthenticator(context, tm);
+                return new CarrierPrivilegeAuthenticator(context, this, tm);
             } else {
                 return null;
             }
diff --git a/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java b/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java
index 88aa329..27c9126 100644
--- a/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java
+++ b/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java
@@ -16,9 +16,10 @@
 
 package com.android.server.connectivity;
 
-import static android.net.NetworkCapabilities.NET_CAPABILITY_CBS;
 import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
 
+import static com.android.server.connectivity.ConnectivityFlags.CARRIER_SERVICE_CHANGED_USE_CALLBACK;
+
 import android.annotation.NonNull;
 import android.content.BroadcastReceiver;
 import android.content.Context;
@@ -44,6 +45,7 @@
 import com.android.networkstack.apishim.common.TelephonyManagerShim;
 import com.android.networkstack.apishim.common.TelephonyManagerShim.CarrierPrivilegesListenerShim;
 import com.android.networkstack.apishim.common.UnsupportedApiLevelException;
+import com.android.server.ConnectivityService;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -73,8 +75,10 @@
     @NonNull
     private final List<CarrierPrivilegesListenerShim> mCarrierPrivilegesChangedListeners =
             new ArrayList<>();
+    private final boolean mUseCallbacksForServiceChanged;
 
     public CarrierPrivilegeAuthenticator(@NonNull final Context c,
+            @NonNull final ConnectivityService.Dependencies deps,
             @NonNull final TelephonyManager t,
             @NonNull final TelephonyManagerShim telephonyManagerShim) {
         mContext = c;
@@ -82,7 +86,9 @@
         mTelephonyManagerShim = telephonyManagerShim;
         mThread = new HandlerThread(TAG);
         mThread.start();
-        mHandler = new Handler(mThread.getLooper()) {};
+        mHandler = new Handler(mThread.getLooper());
+        mUseCallbacksForServiceChanged = deps.isFeatureEnabled(
+                c, CARRIER_SERVICE_CHANGED_USE_CALLBACK);
         synchronized (mLock) {
             mModemCount = mTelephonyManager.getActiveModemCount();
             registerForCarrierChanges();
@@ -91,8 +97,9 @@
     }
 
     public CarrierPrivilegeAuthenticator(@NonNull final Context c,
+            @NonNull final ConnectivityService.Dependencies deps,
             @NonNull final TelephonyManager t) {
-        this(c, t, TelephonyManagerShimImpl.newInstance(t));
+        this(c, deps, t, TelephonyManagerShimImpl.newInstance(t));
     }
 
     /**
diff --git a/service/src/com/android/server/connectivity/ConnectivityFlags.java b/service/src/com/android/server/connectivity/ConnectivityFlags.java
index 9039a14..5aac8f1 100644
--- a/service/src/com/android/server/connectivity/ConnectivityFlags.java
+++ b/service/src/com/android/server/connectivity/ConnectivityFlags.java
@@ -33,6 +33,10 @@
     public static final String NO_REMATCH_ALL_REQUESTS_ON_REGISTER =
             "no_rematch_all_requests_on_register";
 
+    @VisibleForTesting
+    public static final String CARRIER_SERVICE_CHANGED_USE_CALLBACK =
+            "carrier_service_changed_use_callback_version";
+
     private boolean mNoRematchAllRequestsOnRegister;
 
     /**