diff --git a/qa/L0_parameters/class_count_test.py b/qa/L0_parameters/class_count_test.py
new file mode 100755
index 0000000000..9e49ae4ae2
--- /dev/null
+++ b/qa/L0_parameters/class_count_test.py
@@ -0,0 +1,105 @@
+#!/usr/bin/env python3
+
+# Copyright 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of NVIDIA CORPORATION nor the names of its
+#    contributors may be used to endorse or promote products derived
+#    from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import sys
+
+sys.path.append("../common")
+
+import os
+import unittest
+
+import numpy as np
+import test_util as tu
+import tritonclient.grpc as grpcclient
+import tritonclient.http as httpclient
+from tritonclient.utils import InferenceServerException
+
+
+class ClassificationParameterTest(tu.TestResultCollector):
+    def setUp(self):
+        self.protocol = os.environ.get("CLIENT_TYPE", "http")
+        if self.protocol == "http":
+            self.client = httpclient.InferenceServerClient("localhost:8000")
+        else:
+            self.client = grpcclient.InferenceServerClient("localhost:8001")
+
+    def _prepare_io(self, input_data, dtype):
+        if self.protocol == "http":
+            inputs = [httpclient.InferInput("INPUT0", input_data.shape, dtype)]
+            outputs = [httpclient.InferRequestedOutput(name="OUTPUT0", class_count=5)]
+        else:
+            inputs = [grpcclient.InferInput("INPUT0", input_data.shape, dtype)]
+            outputs = [grpcclient.InferRequestedOutput(name="OUTPUT0", class_count=5)]
+        inputs[0].set_data_from_numpy(input_data)
+        return inputs, outputs
+
+    def test_classificattion(self):
+        shape = (1, 8)
+        dtype = "FP32"
+        model_name = "identity_fp32"
+        input_data = np.ones(shape, dtype=np.float32)
+
+        inputs, outputs = self._prepare_io(input_data, dtype)
+        result = self.client.infer(
+            model_name=model_name, inputs=inputs, outputs=outputs
+        )
+        output = result.get_output("OUTPUT0")
+        if self.protocol == "http":
+            output_dtype = output["datatype"]
+        else:
+            output_dtype = output.datatype
+
+        self.assertEqual(output_dtype, "BYTES")
+
+        # Validate shape matches to the class_count
+        output_data = result.as_numpy("OUTPUT0")
+        self.assertIsNotNone(output_data)
+        self.assertEqual(output_data.shape, (1, 5))
+
+        for res_str_bytes in np.nditer(output_data, flags=["refs_ok"]):
+            res_str = res_str_bytes.item().decode("utf-8")
+            self.assertTrue(res_str.startswith("1.000000:"))
+
+    def test_classificattion_unsupported_data_type(self):
+        shape = (1, 8)
+        model_name = "identity_bytes"
+        dtype = "BYTES"
+        input_data = np.array([["test"] * shape[1]], dtype=object)
+
+        inputs, outputs = self._prepare_io(input_data, dtype)
+        with self.assertRaises(InferenceServerException) as e:
+            self.client.infer(model_name=model_name, inputs=inputs, outputs=outputs)
+
+        self.assertIn(
+            "class result not available for output due to unsupported type 'BYTES'",
+            str(e.exception),
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/qa/L0_parameters/test.sh b/qa/L0_parameters/test.sh
index c53b02d4b7..63868237aa 100755
--- a/qa/L0_parameters/test.sh
+++ b/qa/L0_parameters/test.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# Copyright 2023-2024, NVIDIA CORPORATION. All rights reserved.
+# Copyright 2023-2025, NVIDIA CORPORATION. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -97,10 +97,65 @@ for i in "${all_tests[@]}"; do
   wait $SERVER_PID
 done
 
+
+# Test Classification Extension
+PYTHON_MODELS_DIR="${PYTHON_MODELS_DIR:-/opt/tritonserver/qa/python_models}"
+MODELDIR="models"
+TEST_RESULT_FILE="test_results.txt"
+TEST_SCRIPT_PY="./class_count_test.py"
+
+rm -rf $MODELDIR
+mkdir -p "${MODELDIR}/identity_fp32/1"
+cp ${PYTHON_MODELS_DIR}/identity_fp32/config.pbtxt "${MODELDIR}/identity_fp32/"
+cp ${PYTHON_MODELS_DIR}/identity_fp32/model.py "${MODELDIR}/identity_fp32/1/"
+
+mkdir -p "${MODELDIR}/identity_bytes/1"
+cp ${PYTHON_MODELS_DIR}/identity_fp32/config.pbtxt "${MODELDIR}/identity_bytes/"
+cp ${PYTHON_MODELS_DIR}/identity_fp32/model.py "${MODELDIR}/identity_bytes/1/"
+(cd "${MODELDIR}/identity_bytes" && \
+    sed -i 's/identity_fp32/identity_bytes/' config.pbtxt && \
+    sed -i 's/TYPE_FP32/TYPE_STRING/' config.pbtxt )
+
+SERVER_ARGS="--model-repository=`pwd`/${MODELDIR} --log-verbose=1"
+for client_type in http grpc; do
+  export CLIENT_TYPE=$client_type
+  SERVER_LOG="./class_count_test_${client_type}_server.log"
+  CLIENT_LOG="./class_count_test_${client_type}_client.log"
+  rm -f $SERVER_LOG $CLIENT_LOG
+  run_server
+  if [ "$SERVER_PID" == "0" ]; then
+      echo -e "\n***\n*** Failed to start $SERVER\n***"
+      cat $SERVER_LOG
+      exit 1
+  fi
+
+  set +e
+  python3 $TEST_SCRIPT_PY -v >>"$CLIENT_LOG" 2>&1
+  if [ $? -ne 0 ]; then
+      cat $CLIENT_LOG
+      echo -e "\n***\n*** Test Failed - class_count_${client_type}_test_client\n***"
+      RET=1
+  else
+      check_test_results $TEST_RESULT_FILE 2
+      if [ $? -ne 0 ]; then
+          cat $TEST_RESULT_FILE
+          echo -e "\n***\n*** Test Result Verification Failed - class_count_${client_type}_test_client\n***"
+          RET=1
+      fi
+  fi
+  kill $SERVER_PID
+  wait $SERVER_PID
+
+  if [ $? -ne 0 ]; then
+      echo -e "\n***\n*** Test Server shut down non-gracefully\n***"
+      RET=1
+  fi
+  set -e
+done
+
 if [ $RET -eq 0 ]; then
     echo -e "\n***\n*** Test Passed\n***"
 else
-    cat $CLIENT_LOG
     echo -e "\n***\n*** Test FAILED\n***"
 fi
 
diff --git a/src/classification.cc b/src/classification.cc
index 2d8cd26b9e..828edf613d 100644
--- a/src/classification.cc
+++ b/src/classification.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
+// Copyright (c) 2020-2025, NVIDIA CORPORATION. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
@@ -77,8 +77,18 @@ TopkClassifications(
     const TRITONSERVER_DataType datatype, const uint32_t req_class_count,
     std::vector<std::string>* class_strs)
 {
-  const size_t element_cnt =
-      byte_size / TRITONSERVER_DataTypeByteSize(datatype);
+  const uint32_t dtype_byte_size = TRITONSERVER_DataTypeByteSize(datatype);
+  if (dtype_byte_size == 0) {
+    return TRITONSERVER_ErrorNew(
+        TRITONSERVER_ERROR_INVALID_ARG,
+        std::string(
+            std::string("class result not available for output due to "
+                        "unsupported type '") +
+            std::string(TRITONSERVER_DataTypeString(datatype)) + "'")
+            .c_str());
+  }
+
+  const size_t element_cnt = byte_size / dtype_byte_size;
 
   switch (datatype) {
     case TRITONSERVER_TYPE_UINT8: