diff --git a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsMediaSource.java b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsMediaSource.java
index 400061d0190..85042c43549 100644
--- a/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsMediaSource.java
+++ b/extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsMediaSource.java
@@ -76,6 +76,12 @@ public ImaAdsMediaSource(
         adUiViewGroup, eventHandler, eventListener);
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return adsMediaSource.getTag();
+  }
+
   @Override
   public void prepareSourceInternal(
       final ExoPlayer player,
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaSource.java
index 3916d41b61f..1dbb41dfb08 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/ClippingMediaSource.java
@@ -186,6 +186,12 @@ public ClippingMediaSource(
     window = new Timeline.Window();
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return mediaSource.getTag();
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java
index 1f3b01182a4..26667e641f7 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java
@@ -453,6 +453,12 @@ public final synchronized void setShuffleOrder(
     }
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return null;
+  }
+
   @Override
   public final synchronized void prepareSourceInternal(
       ExoPlayer player,
@@ -1069,6 +1075,12 @@ protected void prepareSourceInternal(
       // Do nothing.
     }
 
+    @Override
+    @Nullable
+    public Object getTag() {
+      return null;
+    }
+
     @Override
     protected void releaseSourceInternal() {
       // Do nothing.
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/ExtractorMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/ExtractorMediaSource.java
index 66af3a7e62b..085b5dba717 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/ExtractorMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/ExtractorMediaSource.java
@@ -358,6 +358,12 @@ private ExtractorMediaSource(
     this.tag = tag;
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return tag;
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/LoopingMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/LoopingMediaSource.java
index 78a1e75d90f..cac15d5ed93 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/LoopingMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/LoopingMediaSource.java
@@ -64,6 +64,12 @@ public LoopingMediaSource(MediaSource childSource, int loopCount) {
     mediaPeriodToChildMediaPeriodId = new HashMap<>();
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return childSource.getTag();
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/MediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/MediaSource.java
index d8335131f96..21f4f209222 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/MediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/MediaSource.java
@@ -219,6 +219,12 @@ public int hashCode() {
    */
   void removeEventListener(MediaSourceEventListener eventListener);
 
+  /** Returns the tag set on the media source, or null if none was set. */
+  @Nullable
+  default Object getTag() {
+    return null;
+  }
+
   /**
    * Starts source preparation if not yet started, and adds a listener for timeline and/or manifest
    * updates.
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaSource.java
index ecb4b10c6ac..573e97cb13c 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/MergingMediaSource.java
@@ -98,6 +98,12 @@ public MergingMediaSource(CompositeSequenceableLoaderFactory compositeSequenceab
     timelines = new Timeline[mediaSources.length];
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return mediaSources.length > 0 ? mediaSources[0].getTag() : null;
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaSource.java
index 218bc84b118..966938262e4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaSource.java
@@ -185,6 +185,7 @@ public SingleSampleMediaSource createMediaSource(
   private final LoadErrorHandlingPolicy loadErrorHandlingPolicy;
   private final boolean treatLoadErrorsAsEndOfStream;
   private final Timeline timeline;
+  @Nullable private final Object tag;
 
   private @Nullable TransferListener transferListener;
 
@@ -287,6 +288,7 @@ private SingleSampleMediaSource(
     this.durationUs = durationUs;
     this.loadErrorHandlingPolicy = loadErrorHandlingPolicy;
     this.treatLoadErrorsAsEndOfStream = treatLoadErrorsAsEndOfStream;
+    this.tag = tag;
     dataSpec = new DataSpec(uri, DataSpec.FLAG_ALLOW_GZIP);
     timeline =
         new SinglePeriodTimeline(durationUs, /* isSeekable= */ true, /* isDynamic= */ false, tag);
@@ -294,6 +296,12 @@ private SingleSampleMediaSource(
 
   // MediaSource implementation.
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return tag;
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/ads/AdsMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/ads/AdsMediaSource.java
index 7fc0f22bf39..19ddbd2c542 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/ads/AdsMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/ads/AdsMediaSource.java
@@ -319,6 +319,12 @@ public AdsMediaSource(
     adsLoader.setSupportedContentTypes(adMediaSourceFactory.getSupportedTypes());
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return contentMediaSource.getTag();
+  }
+
   @Override
   public void prepareSourceInternal(
       final ExoPlayer player,
diff --git a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
index b04fcf7247a..1f08a437311 100644
--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
@@ -607,6 +607,12 @@ public void replaceManifestUri(Uri manifestUri) {
 
   // MediaSource implementation.
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return tag;
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaSource.java b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaSource.java
index a075dacf3ae..a9b0c579ac6 100644
--- a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaSource.java
+++ b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaSource.java
@@ -390,6 +390,12 @@ private HlsMediaSource(
     this.tag = tag;
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return tag;
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaSource.java b/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaSource.java
index a756b7f4f1b..103a52a55a0 100644
--- a/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaSource.java
+++ b/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaSource.java
@@ -503,6 +503,12 @@ private SsMediaSource(
 
   // MediaSource implementation.
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    return tag;
+  }
+
   @Override
   public void prepareSourceInternal(
       ExoPlayer player,
diff --git a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSource.java b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSource.java
index 2fca4f42c72..1f0c0c1a406 100644
--- a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSource.java
+++ b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeMediaSource.java
@@ -88,6 +88,13 @@ public FakeMediaSource(@Nullable Timeline timeline, Object manifest,
     this.trackGroupArray = trackGroupArray;
   }
 
+  @Override
+  @Nullable
+  public Object getTag() {
+    boolean hasTimeline = timeline != null && !timeline.isEmpty();
+    return hasTimeline ? timeline.getWindow(0, new Timeline.Window()).tag : null;
+  }
+
   @Override
   public synchronized void prepareSourceInternal(
       ExoPlayer player,