diff --git a/core/api/current.txt b/core/api/current.txt
index 978713abe84dd..c37f5ee841a46 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -42832,6 +42832,7 @@ package android.telephony {
     field public static final String KEY_PREMIUM_CAPABILITY_SUPPORTED_ON_LTE_BOOL = "premium_capability_supported_on_lte_bool";
     field public static final String KEY_PREVENT_CLIR_ACTIVATION_AND_DEACTIVATION_CODE_BOOL = "prevent_clir_activation_and_deactivation_code_bool";
     field public static final String KEY_RADIO_RESTART_FAILURE_CAUSES_INT_ARRAY = "radio_restart_failure_causes_int_array";
+    field public static final String KEY_RATCHET_NR_ADVANCED_BANDWIDTH_IF_RRC_IDLE_BOOL = "ratchet_nr_advanced_bandwidth_if_rrc_idle_bool";
     field public static final String KEY_RCS_CONFIG_SERVER_URL_STRING = "rcs_config_server_url_string";
     field public static final String KEY_READ_ONLY_APN_FIELDS_STRING_ARRAY = "read_only_apn_fields_string_array";
     field public static final String KEY_READ_ONLY_APN_TYPES_STRING_ARRAY = "read_only_apn_types_string_array";
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 79503514c5307..ddb326236dc35 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -2005,6 +2005,19 @@ public class CarrierConfigManager {
     public static final String KEY_INCLUDE_LTE_FOR_NR_ADVANCED_THRESHOLD_BANDWIDTH_BOOL =
             "include_lte_for_nr_advanced_threshold_bandwidth_bool";
 
+    /**
+     * Indicating whether to ratchet the aggregated cell bandwidths on receiving new values when
+     * the device is in RRC IDLE mode.
+     * The aggregated cell bandwidths are used for determining NR advanced state.
+     *
+     * If this is {@code true}, we will only update the aggregate cell bandwidths if the new
+     * aggregate is higher than the current aggregate and the anchor NR cell is the same.
+     * If this is {@code false}, we will always update the aggregate cell bandwidths when receiving
+     * new values.
+     */
+    public static final String KEY_RATCHET_NR_ADVANCED_BANDWIDTH_IF_RRC_IDLE_BOOL =
+            "ratchet_nr_advanced_bandwidth_if_rrc_idle_bool";
+
     /**
      * Boolean indicating if operator name should be shown in the status bar
      * @hide
@@ -9939,6 +9952,7 @@ public class CarrierConfigManager {
         sDefaults.putInt(KEY_LTE_PLUS_THRESHOLD_BANDWIDTH_KHZ_INT, 20000);
         sDefaults.putInt(KEY_NR_ADVANCED_THRESHOLD_BANDWIDTH_KHZ_INT, 0);
         sDefaults.putBoolean(KEY_INCLUDE_LTE_FOR_NR_ADVANCED_THRESHOLD_BANDWIDTH_BOOL, false);
+        sDefaults.putBoolean(KEY_RATCHET_NR_ADVANCED_BANDWIDTH_IF_RRC_IDLE_BOOL, true);
         sDefaults.putIntArray(KEY_CARRIER_NR_AVAILABILITIES_INT_ARRAY,
                 new int[]{CARRIER_NR_AVAILABILITY_NSA, CARRIER_NR_AVAILABILITY_SA});
         sDefaults.putBoolean(KEY_LTE_ENABLED_BOOL, true);