diff --git a/mediapipe/calculators/core/BUILD b/mediapipe/calculators/core/BUILD
index 9c4b3af7c..74398be42 100644
--- a/mediapipe/calculators/core/BUILD
+++ b/mediapipe/calculators/core/BUILD
@@ -328,6 +328,7 @@ cc_library(
         ":concatenate_vector_calculator_cc_proto",
         "//mediapipe/framework:calculator_framework",
         "//mediapipe/framework/api2:node",
+        "//mediapipe/framework/formats:classification_cc_proto",
         "//mediapipe/framework/formats:landmark_cc_proto",
         "//mediapipe/framework/port:ret_check",
         "//mediapipe/framework/port:status",
@@ -344,6 +345,7 @@ cc_test(
         "//mediapipe/framework:calculator_framework",
         "//mediapipe/framework:calculator_runner",
         "//mediapipe/framework:timestamp",
+        "//mediapipe/framework/formats:classification_cc_proto",
         "//mediapipe/framework/formats:landmark_cc_proto",
         "//mediapipe/framework/port:gtest_main",
         "//mediapipe/framework/port:parse_text_proto",
diff --git a/mediapipe/calculators/core/concatenate_proto_list_calculator.cc b/mediapipe/calculators/core/concatenate_proto_list_calculator.cc
index 9dd0dfd99..6c58e1110 100644
--- a/mediapipe/calculators/core/concatenate_proto_list_calculator.cc
+++ b/mediapipe/calculators/core/concatenate_proto_list_calculator.cc
@@ -18,6 +18,7 @@
 #include "mediapipe/calculators/core/concatenate_vector_calculator.pb.h"
 #include "mediapipe/framework/api2/node.h"
 #include "mediapipe/framework/calculator_framework.h"
+#include "mediapipe/framework/formats/classification.pb.h"
 #include "mediapipe/framework/formats/landmark.pb.h"
 #include "mediapipe/framework/port/canonical_errors.h"
 #include "mediapipe/framework/port/ret_check.h"
@@ -111,6 +112,22 @@ class ConcatenateLandmarkListCalculator
 };
 MEDIAPIPE_REGISTER_NODE(ConcatenateLandmarkListCalculator);
 
+class ConcatenateClassificationListCalculator
+    : public ConcatenateListsCalculator<Classification, ClassificationList> {
+ protected:
+  int ListSize(const ClassificationList& list) const override {
+    return list.classification_size();
+  }
+  const Classification GetItem(const ClassificationList& list,
+                               int idx) const override {
+    return list.classification(idx);
+  }
+  Classification* AddItem(ClassificationList& list) const override {
+    return list.add_classification();
+  }
+};
+MEDIAPIPE_REGISTER_NODE(ConcatenateClassificationListCalculator);
+
 }  // namespace api2
 }  // namespace mediapipe
 
diff --git a/mediapipe/calculators/core/concatenate_proto_list_calculator_test.cc b/mediapipe/calculators/core/concatenate_proto_list_calculator_test.cc
index fd116ece7..2167cd9d1 100644
--- a/mediapipe/calculators/core/concatenate_proto_list_calculator_test.cc
+++ b/mediapipe/calculators/core/concatenate_proto_list_calculator_test.cc
@@ -18,6 +18,7 @@
 
 #include "mediapipe/framework/calculator_framework.h"
 #include "mediapipe/framework/calculator_runner.h"
+#include "mediapipe/framework/formats/classification.pb.h"
 #include "mediapipe/framework/formats/landmark.pb.h"
 #include "mediapipe/framework/port/gmock.h"
 #include "mediapipe/framework/port/gtest.h"
@@ -70,6 +71,16 @@ void AddInputLandmarkLists(
   }
 }
 
+void AddInputClassificationLists(
+    const std::vector<ClassificationList>& input_classifications_vec,
+    int64 timestamp, CalculatorRunner* runner) {
+  for (int i = 0; i < input_classifications_vec.size(); ++i) {
+    runner->MutableInputs()->Index(i).packets.push_back(
+        MakePacket<ClassificationList>(input_classifications_vec[i])
+            .At(Timestamp(timestamp)));
+  }
+}
+
 TEST(ConcatenateNormalizedLandmarkListCalculatorTest, EmptyVectorInputs) {
   CalculatorRunner runner("ConcatenateNormalizedLandmarkListCalculator",
                           /*options_string=*/"", /*num_inputs=*/3,
@@ -181,4 +192,39 @@ TEST(ConcatenateNormalizedLandmarkListCalculatorTest, OneEmptyStreamNoOutput) {
   EXPECT_EQ(0, outputs.size());
 }
 
+TEST(ConcatenateClassificationListCalculatorTest, OneTimestamp) {
+  CalculatorRunner runner("ConcatenateClassificationListCalculator",
+                          /*options_string=*/
+                          "[mediapipe.ConcatenateVectorCalculatorOptions.ext]: "
+                          "{only_emit_if_all_present: true}",
+                          /*num_inputs=*/2,
+                          /*num_outputs=*/1, /*num_side_packets=*/0);
+
+  auto input_0 = ParseTextProtoOrDie<ClassificationList>(R"pb(
+    classification: { index: 0 score: 0.2 label: "test_0" }
+    classification: { index: 1 score: 0.3 label: "test_1" }
+    classification: { index: 2 score: 0.4 label: "test_2" }
+  )pb");
+  auto input_1 = ParseTextProtoOrDie<ClassificationList>(R"pb(
+    classification: { index: 3 score: 0.2 label: "test_3" }
+    classification: { index: 4 score: 0.3 label: "test_4" }
+  )pb");
+  std::vector<ClassificationList> inputs = {input_0, input_1};
+  AddInputClassificationLists(inputs, /*timestamp=*/1, &runner);
+  MP_ASSERT_OK(runner.Run());
+
+  const std::vector<Packet>& outputs = runner.Outputs().Index(0).packets;
+  EXPECT_EQ(1, outputs.size());
+  EXPECT_EQ(Timestamp(1), outputs[0].Timestamp());
+  auto result = outputs[0].Get<ClassificationList>();
+  EXPECT_THAT(ParseTextProtoOrDie<ClassificationList>(R"pb(
+                classification: { index: 0 score: 0.2 label: "test_0" }
+                classification: { index: 1 score: 0.3 label: "test_1" }
+                classification: { index: 2 score: 0.4 label: "test_2" }
+                classification: { index: 3 score: 0.2 label: "test_3" }
+                classification: { index: 4 score: 0.3 label: "test_4" }
+              )pb"),
+              EqualsProto(result));
+}
+
 }  // namespace mediapipe