diff --git a/api/system-current.txt b/api/system-current.txt
index 184ed44f4ebd2..863bfdf684b7a 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -4969,6 +4969,28 @@ package android.telephony.ims {
     field public static final int CODE_RADIO_SETUP_FAILURE = 1509; // 0x5e5
     field public static final int CODE_RADIO_UPLINK_FAILURE = 1508; // 0x5e4
     field public static final int CODE_REGISTRATION_ERROR = 1000; // 0x3e8
+    field public static final int CODE_REJECT_1X_COLLISION = 1603; // 0x643
+    field public static final int CODE_REJECT_CALL_ON_OTHER_SUB = 1602; // 0x642
+    field public static final int CODE_REJECT_CALL_TYPE_NOT_ALLOWED = 1605; // 0x645
+    field public static final int CODE_REJECT_CONFERENCE_TTY_NOT_ALLOWED = 1617; // 0x651
+    field public static final int CODE_REJECT_INTERNAL_ERROR = 1612; // 0x64c
+    field public static final int CODE_REJECT_MAX_CALL_LIMIT_REACHED = 1608; // 0x648
+    field public static final int CODE_REJECT_ONGOING_CALL_SETUP = 1607; // 0x647
+    field public static final int CODE_REJECT_ONGOING_CALL_TRANSFER = 1611; // 0x64b
+    field public static final int CODE_REJECT_ONGOING_CALL_UPGRADE = 1616; // 0x650
+    field public static final int CODE_REJECT_ONGOING_CALL_WAITING_DISABLED = 1601; // 0x641
+    field public static final int CODE_REJECT_ONGOING_CONFERENCE_CALL = 1618; // 0x652
+    field public static final int CODE_REJECT_ONGOING_CS_CALL = 1621; // 0x655
+    field public static final int CODE_REJECT_ONGOING_E911_CALL = 1606; // 0x646
+    field public static final int CODE_REJECT_ONGOING_ENCRYPTED_CALL = 1620; // 0x654
+    field public static final int CODE_REJECT_ONGOING_HANDOVER = 1614; // 0x64e
+    field public static final int CODE_REJECT_QOS_FAILURE = 1613; // 0x64d
+    field public static final int CODE_REJECT_SERVICE_NOT_REGISTERED = 1604; // 0x644
+    field public static final int CODE_REJECT_UNKNOWN = 1600; // 0x640
+    field public static final int CODE_REJECT_UNSUPPORTED_SDP_HEADERS = 1610; // 0x64a
+    field public static final int CODE_REJECT_UNSUPPORTED_SIP_HEADERS = 1609; // 0x649
+    field public static final int CODE_REJECT_VT_AVPF_NOT_ALLOWED = 1619; // 0x653
+    field public static final int CODE_REJECT_VT_TTY_NOT_ALLOWED = 1615; // 0x64f
     field public static final int CODE_REMOTE_CALL_DECLINE = 1404; // 0x57c
     field public static final int CODE_SIP_ALTERNATE_EMERGENCY_CALL = 1514; // 0x5ea
     field public static final int CODE_SIP_BAD_ADDRESS = 337; // 0x151
@@ -5240,6 +5262,7 @@ package android.telephony.ims.feature {
     method public android.telephony.ims.stub.ImsUtImplBase getUt();
     method public final void notifyCapabilitiesStatusChanged(android.telephony.ims.feature.MmTelFeature.MmTelCapabilities);
     method public final void notifyIncomingCall(android.telephony.ims.stub.ImsCallSessionImplBase, android.os.Bundle);
+    method public final void notifyRejectedCall(android.telephony.ims.ImsCallProfile, android.telephony.ims.ImsReasonInfo);
     method public final void notifyVoiceMessageCountUpdate(int);
     method public void onFeatureReady();
     method public void onFeatureRemoved();
diff --git a/telephony/java/android/telephony/ims/ImsReasonInfo.java b/telephony/java/android/telephony/ims/ImsReasonInfo.java
index 7d654305015ea..e70e6334f8467 100644
--- a/telephony/java/android/telephony/ims/ImsReasonInfo.java
+++ b/telephony/java/android/telephony/ims/ImsReasonInfo.java
@@ -399,6 +399,160 @@ public final class ImsReasonInfo implements Parcelable {
      */
     public static final int CODE_UNOBTAINABLE_NUMBER = 1515;
 
+    /**
+     * The rejection cause is not known.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_UNKNOWN = 1600;
+
+    /**
+     * Ongoing call, and call waiting is disabled.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_CALL_WAITING_DISABLED = 1601;
+
+    /**
+     * A call is ongoing on another sub.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_CALL_ON_OTHER_SUB = 1602;
+
+    /**
+     * CDMA call collision.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_1X_COLLISION = 1603;
+
+    /**
+     * IMS is not registered for service yet.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_SERVICE_NOT_REGISTERED = 1604;
+
+    /**
+     * The call type is not allowed on the current RAT.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_CALL_TYPE_NOT_ALLOWED = 1605;
+
+    /**
+     * And emergency call is ongoing.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_E911_CALL = 1606;
+
+    /**
+     * Another call is in the process of being establilshed.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_CALL_SETUP = 1607;
+
+    /**
+     * Maximum number of allowed calls are already in progress.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_MAX_CALL_LIMIT_REACHED = 1608;
+
+    /**
+     * Invalid/unsupported SIP headers received.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_UNSUPPORTED_SIP_HEADERS = 1609;
+
+    /**
+     * Invalid/unsupported SDP headers received.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_UNSUPPORTED_SDP_HEADERS = 1610;
+
+    /**
+     * A call transfer is in progress.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_CALL_TRANSFER = 1611;
+
+    /**
+     * An internal error occured while processing the call.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_INTERNAL_ERROR = 1612;
+
+    /**
+     * Call failure due to lack of dedicated bearer.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_QOS_FAILURE = 1613;
+
+    /**
+     * A call handover is in progress.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_HANDOVER = 1614;
+
+    /**
+     * Video calling not supported with TTY.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_VT_TTY_NOT_ALLOWED = 1615;
+
+    /**
+     * A call upgrade is in progress.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_CALL_UPGRADE = 1616;
+
+    /**
+     * Call from conference server, when TTY mode is ON.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_CONFERENCE_TTY_NOT_ALLOWED = 1617;
+
+    /**
+     * A conference call is ongoing.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_CONFERENCE_CALL = 1618;
+
+    /**
+     * A video call with AVPF is not supported.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_VT_AVPF_NOT_ALLOWED = 1619;
+
+    /**
+     * And encrypted call is ongoing; other calls not supported.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_ENCRYPTED_CALL = 1620;
+
+    /**
+     * A CS call is ongoing.
+     * <p>
+     * Used with implicit call rejection.
+     */
+    public static final int CODE_REJECT_ONGOING_CS_CALL = 1621;
+
     /* OEM specific error codes. To be used by OEMs when they don't want to
    reveal error code which would be replaced by ERROR_UNSPECIFIED */
     public static final int CODE_OEM_CAUSE_1 = 0xf001;
diff --git a/telephony/java/android/telephony/ims/aidl/IImsMmTelListener.aidl b/telephony/java/android/telephony/ims/aidl/IImsMmTelListener.aidl
index 904e7cad9c149..7bbe30a444b9a 100644
--- a/telephony/java/android/telephony/ims/aidl/IImsMmTelListener.aidl
+++ b/telephony/java/android/telephony/ims/aidl/IImsMmTelListener.aidl
@@ -18,6 +18,9 @@ package android.telephony.ims.aidl;
 
 import android.os.Bundle;
 
+import android.telephony.ims.ImsCallProfile;
+import android.telephony.ims.ImsReasonInfo;
+
 import com.android.ims.internal.IImsCallSession;
 
 /**
@@ -26,5 +29,6 @@ import com.android.ims.internal.IImsCallSession;
  */
 oneway interface IImsMmTelListener {
     void onIncomingCall(IImsCallSession c, in Bundle extras);
+    void onRejectedCall(in ImsCallProfile callProfile, in ImsReasonInfo reason);
     void onVoiceMessageCountUpdate(int count);
-}
\ No newline at end of file
+}
diff --git a/telephony/java/android/telephony/ims/feature/MmTelFeature.java b/telephony/java/android/telephony/ims/feature/MmTelFeature.java
index aaf1a1cf8f206..f12540f8dd137 100644
--- a/telephony/java/android/telephony/ims/feature/MmTelFeature.java
+++ b/telephony/java/android/telephony/ims/feature/MmTelFeature.java
@@ -36,6 +36,7 @@ import android.telephony.ims.stub.ImsUtImplBase;
 import android.util.Log;
 
 import android.telephony.ims.ImsCallProfile;
+import android.telephony.ims.ImsReasonInfo;
 import com.android.ims.internal.IImsCallSession;
 import com.android.ims.internal.IImsEcbm;
 import com.android.ims.internal.IImsMultiEndpoint;
@@ -325,6 +326,16 @@ public class MmTelFeature extends ImsFeature {
 
         }
 
+        /**
+         * Called when the IMS provider implicitly rejects an incoming call during setup.
+         * @param callProfile An {@link ImsCallProfile} with the call details.
+         * @param reason The {@link ImsReasonInfo} reason for call rejection.
+         */
+        @Override
+        public void onRejectedCall(ImsCallProfile callProfile, ImsReasonInfo reason) {
+
+        }
+
         /**
          * Updates the Listener when the voice message count for IMS has changed.
          * @param count an integer representing the new message count.
@@ -428,6 +439,26 @@ public class MmTelFeature extends ImsFeature {
         }
     }
 
+    /**
+     * Notify the framework that a call has been implicitly rejected by this MmTelFeature
+     * during call setup.
+     * @param callProfile The {@link ImsCallProfile} IMS call profile with details.
+     *        This can be null if no call information is available for the rejected call.
+     * @param reason The {@link ImsReasonInfo} call rejection reason.
+     */
+    public final void notifyRejectedCall(ImsCallProfile callProfile, ImsReasonInfo reason) {
+        synchronized (mLock) {
+            if (mListener == null) {
+                throw new IllegalStateException("Session is not available.");
+            }
+            try {
+                mListener.onRejectedCall(callProfile, reason);
+            } catch (RemoteException e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
     /**
      *
      * @hide