diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 837cf8b28ff84..cff90bb9b8483 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -504,7 +504,12 @@ public class CarrierConfigManager {
     /** Control whether users can choose a network operator. */
     public static final String KEY_OPERATOR_SELECTION_EXPAND_BOOL = "operator_selection_expand_bool";
 
-    /** Used in Cellular Network Settings for preferred network type. */
+    /**
+     * Used in the Preferred Network Types menu to determine if the 2G option is displayed.
+     * Value defaults to false as of Android T to discourage the use of insecure 2G protocols.
+     *
+     * @see #KEY_HIDE_ENABLE_2G
+     */
     public static final String KEY_PREFER_2G_BOOL = "prefer_2g_bool";
 
     /**
@@ -8594,7 +8599,7 @@ public class CarrierConfigManager {
         sDefaults.putBoolean(KEY_IGNORE_SIM_NETWORK_LOCKED_EVENTS_BOOL, false);
         sDefaults.putBoolean(KEY_MDN_IS_ADDITIONAL_VOICEMAIL_NUMBER_BOOL, false);
         sDefaults.putBoolean(KEY_OPERATOR_SELECTION_EXPAND_BOOL, true);
-        sDefaults.putBoolean(KEY_PREFER_2G_BOOL, true);
+        sDefaults.putBoolean(KEY_PREFER_2G_BOOL, false);
         sDefaults.putBoolean(KEY_4G_ONLY_BOOL, false);
         sDefaults.putBoolean(KEY_SHOW_APN_SETTING_CDMA_BOOL, false);
         sDefaults.putBoolean(KEY_SHOW_CDMA_CHOICES_BOOL, false);