diff --git a/api/current.txt b/api/current.txt
index f13601e..81dd965 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -22496,6 +22496,7 @@
     method public void setRatingType(int);
     method public void setSessionActivity(android.app.PendingIntent);
     field public static final int FLAG_HANDLES_MEDIA_BUTTONS = 1; // 0x1
+    field public static final int FLAG_HANDLES_PREPARE_ONLY = 4; // 0x4
     field public static final int FLAG_HANDLES_TRANSPORT_CONTROLS = 2; // 0x2
   }
 
@@ -22574,6 +22575,7 @@
     field public static final long ACTION_SKIP_TO_QUEUE_ITEM = 4096L; // 0x1000L
     field public static final long ACTION_STOP = 1L; // 0x1L
     field public static final android.os.Parcelable.Creator<android.media.session.PlaybackState> CREATOR;
+    field public static final java.lang.String EXTRA_PREPARE_ONLY = "android.media.session.extra.PREPARE_ONLY";
     field public static final long PLAYBACK_POSITION_UNKNOWN = -1L; // 0xffffffffffffffffL
     field public static final int STATE_BUFFERING = 6; // 0x6
     field public static final int STATE_CONNECTING = 8; // 0x8
diff --git a/api/system-current.txt b/api/system-current.txt
index 0d33503..f992037 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -23837,6 +23837,7 @@
     method public void setRatingType(int);
     method public void setSessionActivity(android.app.PendingIntent);
     field public static final int FLAG_HANDLES_MEDIA_BUTTONS = 1; // 0x1
+    field public static final int FLAG_HANDLES_PREPARE_ONLY = 4; // 0x4
     field public static final int FLAG_HANDLES_TRANSPORT_CONTROLS = 2; // 0x2
   }
 
@@ -23915,6 +23916,7 @@
     field public static final long ACTION_SKIP_TO_QUEUE_ITEM = 4096L; // 0x1000L
     field public static final long ACTION_STOP = 1L; // 0x1L
     field public static final android.os.Parcelable.Creator<android.media.session.PlaybackState> CREATOR;
+    field public static final java.lang.String EXTRA_PREPARE_ONLY = "android.media.session.extra.PREPARE_ONLY";
     field public static final long PLAYBACK_POSITION_UNKNOWN = -1L; // 0xffffffffffffffffL
     field public static final int STATE_BUFFERING = 6; // 0x6
     field public static final int STATE_CONNECTING = 8; // 0x8
diff --git a/api/test-current.txt b/api/test-current.txt
index 48fd6f0..7522caa 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -22505,6 +22505,7 @@
     method public void setRatingType(int);
     method public void setSessionActivity(android.app.PendingIntent);
     field public static final int FLAG_HANDLES_MEDIA_BUTTONS = 1; // 0x1
+    field public static final int FLAG_HANDLES_PREPARE_ONLY = 4; // 0x4
     field public static final int FLAG_HANDLES_TRANSPORT_CONTROLS = 2; // 0x2
   }
 
@@ -22583,6 +22584,7 @@
     field public static final long ACTION_SKIP_TO_QUEUE_ITEM = 4096L; // 0x1000L
     field public static final long ACTION_STOP = 1L; // 0x1L
     field public static final android.os.Parcelable.Creator<android.media.session.PlaybackState> CREATOR;
+    field public static final java.lang.String EXTRA_PREPARE_ONLY = "android.media.session.extra.PREPARE_ONLY";
     field public static final long PLAYBACK_POSITION_UNKNOWN = -1L; // 0xffffffffffffffffL
     field public static final int STATE_BUFFERING = 6; // 0x6
     field public static final int STATE_CONNECTING = 8; // 0x8
diff --git a/media/java/android/media/session/MediaController.java b/media/java/android/media/session/MediaController.java
index b1a51a56..3d9b60d 100644
--- a/media/java/android/media/session/MediaController.java
+++ b/media/java/android/media/session/MediaController.java
@@ -605,6 +605,7 @@
         /**
          * Request that the player start playback for a specific media id.
          *
+         * @see PlaybackState#EXTRA_PREPARE_ONLY
          * @param mediaId The id of the requested media.
          * @param extras Optional extras that can include extra information about the media item
          *               to be played.
@@ -626,6 +627,7 @@
          * An empty or null query should be treated as a request to play any
          * music.
          *
+         * @see PlaybackState#EXTRA_PREPARE_ONLY
          * @param query The search query.
          * @param extras Optional extras that can include extra information
          *            about the query.
@@ -646,6 +648,7 @@
         /**
          * Request that the player start playback for a specific {@link Uri}.
          *
+         * @see PlaybackState#EXTRA_PREPARE_ONLY
          * @param uri  The URI of the requested media.
          * @param extras Optional extras that can include extra information about the media item
          *               to be played.
diff --git a/media/java/android/media/session/MediaSession.java b/media/java/android/media/session/MediaSession.java
index e1e9b79..8c5b19c 100644
--- a/media/java/android/media/session/MediaSession.java
+++ b/media/java/android/media/session/MediaSession.java
@@ -87,6 +87,12 @@
     public static final int FLAG_HANDLES_TRANSPORT_CONTROLS = 1 << 1;
 
     /**
+     * Set this flag on the session to indicate that it can handle
+     * the {@link PlaybackState#EXTRA_PREPARE_ONLY} field.
+     */
+    public static final int FLAG_HANDLES_PREPARE_ONLY = 1 << 2;
+
+    /**
      * System only flag for a session that needs to have priority over all other
      * sessions. This flag ensures this session will receive media button events
      * regardless of the current ordering in the system.
@@ -100,6 +106,7 @@
     @IntDef(flag = true, value = {
             FLAG_HANDLES_MEDIA_BUTTONS,
             FLAG_HANDLES_TRANSPORT_CONTROLS,
+            FLAG_HANDLES_PREPARE_ONLY,
             FLAG_EXCLUSIVE_GLOBAL_PRIORITY })
     public @interface SessionFlags { }
 
diff --git a/media/java/android/media/session/PlaybackState.java b/media/java/android/media/session/PlaybackState.java
index bbe04b5..1079a1f 100644
--- a/media/java/android/media/session/PlaybackState.java
+++ b/media/java/android/media/session/PlaybackState.java
@@ -133,6 +133,21 @@
     public static final long ACTION_PLAY_FROM_URI = 1 << 13;
 
     /**
+     * Used as an optional boolean extra field in
+     * {@link MediaController.TransportControls#playFromMediaId},
+     * {@link MediaController.TransportControls#playFromSearch}, and
+     * {@link MediaController.TransportControls#playFromUri}. Value of {@code true} overrides
+     * the default behavior of starting the playback after preparing. Check
+     * {@link MediaSession#FLAG_HANDLES_PREPARE_ONLY} to see if the media session supports this.
+     *
+     * @see MediaSession#FLAG_HANDLES_PREPARE_ONLY
+     * @see MediaController.TransportControls#playFromMediaId
+     * @see MediaController.TransportControls#playFromSearch
+     * @see MediaController.TransportControls#playFromUri
+     */
+    public static final String EXTRA_PREPARE_ONLY = "android.media.session.extra.PREPARE_ONLY";
+
+    /**
      * This is the default playback state and indicates that no media has been
      * added yet, or the performer has been reset and has no content to play.
      *