diff --git a/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.java b/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.java
index e1ad4b447864..59db2f95cf90 100644
--- a/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.java
+++ b/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.java
@@ -2725,9 +2725,6 @@ public WriteResult expand(PCollection<T> input) {
       if (input.isBounded() == IsBounded.BOUNDED) {
         checkArgument(!getAutoSharding(), "Auto-sharding is only applicable to unbounded input.");
       }
-      if (method == Write.Method.STORAGE_WRITE_API) {
-        checkArgument(!getAutoSharding(), "Auto sharding not yet available for Storage API writes");
-      }
 
       if (getJsonTimePartitioning() != null) {
         checkArgument(
@@ -3023,7 +3020,8 @@ private <DestinationT> WriteResult continueExpandTyped(
                 getStorageApiTriggeringFrequency(bqOptions),
                 getBigQueryServices(),
                 getStorageApiNumStreams(bqOptions),
-                method == Method.STORAGE_API_AT_LEAST_ONCE);
+                method == Method.STORAGE_API_AT_LEAST_ONCE,
+                getAutoSharding());
         return input.apply("StorageApiLoads", storageApiLoads);
       } else {
         throw new RuntimeException("Unexpected write method " + method);
diff --git a/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/StorageApiLoads.java b/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/StorageApiLoads.java
index a38c283f442c..20d1be9a2959 100644
--- a/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/StorageApiLoads.java
+++ b/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/StorageApiLoads.java
@@ -52,6 +52,7 @@ public class StorageApiLoads<DestinationT, ElementT>
   private final BigQueryServices bqServices;
   private final int numShards;
   private final boolean allowInconsistentWrites;
+  private final boolean allowAutosharding;
 
   public StorageApiLoads(
       Coder<DestinationT> destinationCoder,
@@ -61,7 +62,8 @@ public StorageApiLoads(
       Duration triggeringFrequency,
       BigQueryServices bqServices,
       int numShards,
-      boolean allowInconsistentWrites) {
+      boolean allowInconsistentWrites,
+      boolean allowAutosharding) {
     this.destinationCoder = destinationCoder;
     this.dynamicDestinations = dynamicDestinations;
     this.createDisposition = createDisposition;
@@ -70,6 +72,7 @@ public StorageApiLoads(
     this.bqServices = bqServices;
     this.numShards = numShards;
     this.allowInconsistentWrites = allowInconsistentWrites;
+    this.allowAutosharding = allowAutosharding;
   }
 
   @Override
@@ -136,9 +139,6 @@ public WriteResult expandTriggered(
     // Handle triggered, low-latency loads into BigQuery.
     PCollection<KV<DestinationT, ElementT>> inputInGlobalWindow =
         input.apply("rewindowIntoGlobal", Window.into(new GlobalWindows()));
-
-    // First shard all the records.
-    // TODO(reuvenlax): Add autosharding support so that users don't have to pick a shard count.
     PCollectionTuple result =
         inputInGlobalWindow
             .apply(
@@ -154,43 +154,61 @@ public WriteResult expandTriggered(
                     successfulRowsTag,
                     BigQueryStorageApiInsertErrorCoder.of(),
                     successCoder));
-    PCollection<KV<ShardedKey<DestinationT>, StorageApiWritePayload>> shardedRecords =
-        result
-            .get(successfulRowsTag)
-            .apply(
-                "AddShard",
-                ParDo.of(
-                    new DoFn<
-                        KV<DestinationT, StorageApiWritePayload>,
-                        KV<ShardedKey<DestinationT>, StorageApiWritePayload>>() {
-                      int shardNumber;
-
-                      @Setup
-                      public void setup() {
-                        shardNumber = ThreadLocalRandom.current().nextInt(numShards);
-                      }
-
-                      @ProcessElement
-                      public void processElement(
-                          @Element KV<DestinationT, StorageApiWritePayload> element,
-                          OutputReceiver<KV<ShardedKey<DestinationT>, StorageApiWritePayload>> o) {
-                        DestinationT destination = element.getKey();
-                        ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES);
-                        buffer.putInt(++shardNumber % numShards);
-                        o.output(
-                            KV.of(ShardedKey.of(destination, buffer.array()), element.getValue()));
-                      }
-                    }))
-            .setCoder(KvCoder.of(ShardedKey.Coder.of(destinationCoder), payloadCoder));
-
-    PCollection<KV<ShardedKey<DestinationT>, Iterable<StorageApiWritePayload>>> groupedRecords =
-        shardedRecords.apply(
-            "GroupIntoBatches",
-            GroupIntoBatches.<ShardedKey<DestinationT>, StorageApiWritePayload>ofByteSize(
-                    MAX_BATCH_SIZE_BYTES,
-                    (StorageApiWritePayload e) -> (long) e.getPayload().length)
-                .withMaxBufferingDuration(triggeringFrequency));
 
+    PCollection<KV<ShardedKey<DestinationT>, Iterable<StorageApiWritePayload>>> groupedRecords;
+
+    if (this.allowAutosharding) {
+      groupedRecords =
+          result
+              .get(successfulRowsTag)
+              .apply(
+                  "GroupIntoBatches",
+                  GroupIntoBatches.<DestinationT, StorageApiWritePayload>ofByteSize(
+                          MAX_BATCH_SIZE_BYTES,
+                          (StorageApiWritePayload e) -> (long) e.getPayload().length)
+                      .withMaxBufferingDuration(triggeringFrequency)
+                      .withShardedKey());
+
+    } else {
+      PCollection<KV<ShardedKey<DestinationT>, StorageApiWritePayload>> shardedRecords =
+          result
+              .get(successfulRowsTag)
+              .apply(
+                  "AddShard",
+                  ParDo.of(
+                      new DoFn<
+                          KV<DestinationT, StorageApiWritePayload>,
+                          KV<ShardedKey<DestinationT>, StorageApiWritePayload>>() {
+                        int shardNumber;
+
+                        @Setup
+                        public void setup() {
+                          shardNumber = ThreadLocalRandom.current().nextInt(numShards);
+                        }
+
+                        @ProcessElement
+                        public void processElement(
+                            @Element KV<DestinationT, StorageApiWritePayload> element,
+                            OutputReceiver<KV<ShardedKey<DestinationT>, StorageApiWritePayload>>
+                                o) {
+                          DestinationT destination = element.getKey();
+                          ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES);
+                          buffer.putInt(++shardNumber % numShards);
+                          o.output(
+                              KV.of(
+                                  ShardedKey.of(destination, buffer.array()), element.getValue()));
+                        }
+                      }))
+              .setCoder(KvCoder.of(ShardedKey.Coder.of(destinationCoder), payloadCoder));
+
+      groupedRecords =
+          shardedRecords.apply(
+              "GroupIntoBatches",
+              GroupIntoBatches.<ShardedKey<DestinationT>, StorageApiWritePayload>ofByteSize(
+                      MAX_BATCH_SIZE_BYTES,
+                      (StorageApiWritePayload e) -> (long) e.getPayload().length)
+                  .withMaxBufferingDuration(triggeringFrequency));
+    }
     groupedRecords.apply(
         "StorageApiWriteSharded",
         new StorageApiWritesShardedRecords<>(
diff --git a/sdks/java/io/google-cloud-platform/src/test/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIOWriteTest.java b/sdks/java/io/google-cloud-platform/src/test/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIOWriteTest.java
index 1bf78ed70d82..270149acd398 100644
--- a/sdks/java/io/google-cloud-platform/src/test/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIOWriteTest.java
+++ b/sdks/java/io/google-cloud-platform/src/test/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIOWriteTest.java
@@ -1190,19 +1190,21 @@ protected void writeString(org.apache.avro.Schema schema, Object datum, Encoder
 
   @Test
   public void testStreamingWrite() throws Exception {
-    streamingWrite(false);
+    autoShardingWrite(false, false);
   }
 
   @Test
   public void testStreamingWriteWithAutoSharding() throws Exception {
-    if (useStorageApi) {
-      return;
-    }
-    streamingWrite(true);
+    autoShardingWrite(true, false);
   }
 
-  private void streamingWrite(boolean autoSharding) throws Exception {
-    if (!useStreaming) {
+  @Test
+  public void testStorageApiWriteWithAutoSharding() throws Exception {
+    autoShardingWrite(true, true);
+  }
+
+  private void autoShardingWrite(boolean autoSharding, boolean storageAPIWrite) throws Exception {
+    if (!useStreaming && !storageAPIWrite) {
       return;
     }
     BigQueryIO.Write<TableRow> write =
@@ -1220,6 +1222,12 @@ private void streamingWrite(boolean autoSharding) throws Exception {
     if (autoSharding) {
       write = write.withAutoSharding();
     }
+    if (storageAPIWrite) {
+      write =
+          write
+              .withTriggeringFrequency(Duration.standardSeconds(5))
+              .withMethod(Method.STORAGE_WRITE_API);
+    }
     p.apply(
             Create.of(
                     new TableRow().set("name", "a").set("number", "1"),