diff --git a/api/system-current.txt b/api/system-current.txt
index 71cef3c..a8c5d99 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -5256,6 +5256,7 @@
     method public deprecated boolean getDataEnabled();
     method public deprecated boolean getDataEnabled(int);
     method public boolean getEmergencyCallbackMode();
+    method public java.lang.String getIsimDomain();
     method public int getSimApplicationState();
     method public int getSimCardState();
     method public java.util.List<android.telephony.TelephonyHistogram> getTelephonyHistograms();
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 7f27009..edddcd1 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -4139,11 +4139,16 @@
     }
 
     /**
-     * Returns the IMS home network domain name that was loaded from the ISIM.
-     * @return the IMS domain name, or null if not present or not loaded
+     * Returns the IMS home network domain name that was loaded from the ISIM {@see #APPTYPE_ISIM}.
+     * @return the IMS domain name. Returns {@code null} if ISIM hasn't been loaded or IMS domain
+     * hasn't been loaded or isn't present on the ISIM.
+     *
+     * <p>Requires Permission:
+     * {@link android.Manifest.permission#READ_PRIVILEGED_PHONE_STATE READ_PRIVILEGED_PHONE_STATE}
      * @hide
      */
-    @UnsupportedAppUsage
+    @SystemApi
+    @RequiresPermission(android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE)
     public String getIsimDomain() {
         try {
             IPhoneSubInfo info = getSubscriberInfo();