diff --git a/common/flags.aconfig b/common/flags.aconfig
index 7235202..0c46b48 100644
--- a/common/flags.aconfig
+++ b/common/flags.aconfig
@@ -27,3 +27,10 @@
   description: "Set data saver through ConnectivityManager API"
   bug: "297836825"
 }
+
+flag {
+  name: "support_is_uid_networking_blocked"
+  namespace: "android_core_networking"
+  description: "This flag controls whether isUidNetworkingBlocked is supported"
+  bug: "297836825"
+}
diff --git a/framework/api/module-lib-current.txt b/framework/api/module-lib-current.txt
index 782e20a..4d55067 100644
--- a/framework/api/module-lib-current.txt
+++ b/framework/api/module-lib-current.txt
@@ -14,6 +14,7 @@
     method @NonNull public static android.util.Range<java.lang.Integer> getIpSecNetIdRange();
     method @Nullable @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_STACK, android.Manifest.permission.NETWORK_SETTINGS}) public android.net.LinkProperties getRedactedLinkPropertiesForPackage(@NonNull android.net.LinkProperties, int, @NonNull String);
     method @Nullable @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_STACK, android.Manifest.permission.NETWORK_SETTINGS}) public android.net.NetworkCapabilities getRedactedNetworkCapabilitiesForPackage(@NonNull android.net.NetworkCapabilities, int, @NonNull String);
+    method @FlaggedApi("com.android.net.flags.support_is_uid_networking_blocked") @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public boolean isUidNetworkingBlocked(int, boolean);
     method @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_SETTINGS}) public void registerDefaultNetworkCallbackForUid(int, @NonNull android.net.ConnectivityManager.NetworkCallback, @NonNull android.os.Handler);
     method @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_SETTINGS, android.Manifest.permission.NETWORK_SETUP_WIZARD, android.Manifest.permission.CONNECTIVITY_USE_RESTRICTED_NETWORKS}) public void registerSystemDefaultNetworkCallback(@NonNull android.net.ConnectivityManager.NetworkCallback, @NonNull android.os.Handler);
     method @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.Manifest.permission.NETWORK_STACK, android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK}) public void removeUidFromMeteredNetworkAllowList(int);
diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index f44fd0e..eb8f8c3 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -133,6 +133,8 @@
     public static class Flags {
         static final String SET_DATA_SAVER_VIA_CM =
                 "com.android.net.flags.set_data_saver_via_cm";
+        static final String SUPPORT_IS_UID_NETWORKING_BLOCKED =
+                "com.android.net.flags.support_is_uid_networking_blocked";
     }
 
     /**
@@ -6311,8 +6313,8 @@
     // is provided by linux file group permission AID_NET_BW_ACCT and the
     // selinux context fs_bpf_net*.
     // Only the system server process and the network stack have access.
-    // TODO: Expose api when ready.
-    // @SystemApi(client = MODULE_LIBRARIES)
+    @FlaggedApi(Flags.SUPPORT_IS_UID_NETWORKING_BLOCKED)
+    @SystemApi(client = MODULE_LIBRARIES)
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)  // BPF maps were only mainlined in T
     @RequiresPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK)
     public boolean isUidNetworkingBlocked(int uid, boolean isNetworkMetered) {
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
index 5893de7..bb32052 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
@@ -37,6 +37,7 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import android.annotation.NonNull;
 import android.app.ActivityManager;
 import android.app.Instrumentation;
 import android.app.NotificationManager;
@@ -438,6 +439,42 @@
     }
 
     /**
+     * Asserts whether the network is blocked by accessing bpf maps if command-line tool supports.
+     */
+    void assertNetworkAccessBlockedByBpf(boolean expectBlocked, int uid, boolean metered) {
+        final String result;
+        try {
+            result = executeShellCommand(
+                    "cmd network_stack is-uid-networking-blocked " + uid + " " + metered);
+        } catch (AssertionError e) {
+            // If NetworkStack is too old to support this command, ignore and continue
+            // this test to verify other parts.
+            if (e.getMessage().contains("No shell command implementation.")) {
+                return;
+            }
+            throw e;
+        }
+
+        // Tethering module is too old.
+        if (result.contains("API is unsupported")) {
+            return;
+        }
+
+        assertEquals(expectBlocked, parseBooleanOrThrow(result.trim()));
+    }
+
+    /**
+     * Similar to {@link Boolean#parseBoolean} but throws when the input
+     * is unexpected instead of returning false.
+     */
+    private static boolean parseBooleanOrThrow(@NonNull String s) {
+        // Don't use Boolean.parseBoolean
+        if ("true".equalsIgnoreCase(s)) return true;
+        if ("false".equalsIgnoreCase(s)) return false;
+        throw new IllegalArgumentException("Unexpected: " + s);
+    }
+
+    /**
      * Checks whether the network is available as expected.
      *
      * @return error message with the mismatch (or empty if assertion passed).
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java
index 0715e32..ab3cf14 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java
@@ -236,16 +236,19 @@
             // Enable restrict background
             setRestrictBackground(true);
             assertBackgroundNetworkAccess(false);
+            assertNetworkAccessBlockedByBpf(true, mUid, true /* metered */);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, true);
 
             // Add to whitelist
             addRestrictBackgroundWhitelist(mUid);
             assertBackgroundNetworkAccess(true);
+            assertNetworkAccessBlockedByBpf(false, mUid, true /* metered */);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, false);
 
             // Remove from whitelist
             removeRestrictBackgroundWhitelist(mUid);
             assertBackgroundNetworkAccess(false);
+            assertNetworkAccessBlockedByBpf(true, mUid, true /* metered */);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, true);
         } finally {
             mMeterednessConfiguration.resetNetworkMeteredness();
@@ -257,11 +260,13 @@
                 true /* hasCapability */, NET_CAPABILITY_NOT_METERED);
         try {
             assertBackgroundNetworkAccess(true);
+            assertNetworkAccessBlockedByBpf(false, mUid, false /* metered */);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, false);
 
             // Disable restrict background, should not trigger callback
             setRestrictBackground(false);
             assertBackgroundNetworkAccess(true);
+            assertNetworkAccessBlockedByBpf(false, mUid, false /* metered */);
         } finally {
             mMeterednessConfiguration.resetNetworkMeteredness();
         }
@@ -275,11 +280,13 @@
             setBatterySaverMode(true);
             assertBackgroundNetworkAccess(false);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, true);
+            assertNetworkAccessBlockedByBpf(true, mUid, true /* metered */);
 
             // Disable Power Saver
             setBatterySaverMode(false);
             assertBackgroundNetworkAccess(true);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, false);
+            assertNetworkAccessBlockedByBpf(false, mUid, true /* metered */);
         } finally {
             mMeterednessConfiguration.resetNetworkMeteredness();
         }
@@ -293,11 +300,13 @@
             setBatterySaverMode(true);
             assertBackgroundNetworkAccess(false);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, true);
+            assertNetworkAccessBlockedByBpf(true, mUid, false /* metered */);
 
             // Disable Power Saver
             setBatterySaverMode(false);
             assertBackgroundNetworkAccess(true);
             mTestNetworkCallback.expectBlockedStatusCallbackEventually(mNetwork, false);
+            assertNetworkAccessBlockedByBpf(false, mUid, false /* metered */);
         } finally {
             mMeterednessConfiguration.resetNetworkMeteredness();
         }