diff --git a/onnxruntime/core/providers/openvino/openvino_provider_factory.cc b/onnxruntime/core/providers/openvino/openvino_provider_factory.cc
index 4a1b2b83c9f81..22dc0abbb44a7 100644
--- a/onnxruntime/core/providers/openvino/openvino_provider_factory.cc
+++ b/onnxruntime/core/providers/openvino/openvino_provider_factory.cc
@@ -445,17 +445,35 @@ struct OpenVINO_Provider : Provider {
       return Status(common::ONNXRUNTIME, ORT_EP_FAIL, "No devices provided to CreateEp");
     }
 
-    // Block setting certain provider options via AppendExecutionProvider_V2
-    // TODO: Expand this out and give better guidance for keys that should now flow through load_config.
-    const std::unordered_set<std::string> blocked_provider_keys = {
-      "device_type", "device_id", "device_luid", "cache_dir", "precision",
-      "context", "num_of_threads", "model_priority", "num_streams",
-      "enable_opencl_throttling", "enable_qdq_optimizer", "disable_dynamic_shapes"};
+    // For provider options that we don't support anymore, give some guidance & examples
+    // about how to make use of the option through load_config.
+    const std::vector<std::pair<std::string, std::string>> block_and_advise_entries = {
+      {"cache_dir", "\"CACHE_DIR\": \"<filesystem_path>\""},
+      {"precision", "\"INFERENCE_PRECISION_HINT\": \"F32\""},
+      {"num_streams", "\"NUM_STREAMS\": \"1\""},
+      {"model_priority", "\"MODEL_PRIORITY\": \"LOW\""},
+      {"enable_opencl_throttling", "\"GPU\": {\"PLUGIN_THROTTLE\": \"1\"}"},
+      {"enable_qdq_optimizer", "\"NPU\": {\"NPU_QDQ_OPTIMIZATION\": \"YES\"}"}
+    };
+
+    for (auto& block_and_advise_entry : block_and_advise_entries) {
+      if (provider_options.find(block_and_advise_entry.first) != provider_options.end()) {
+        std::string message = "OpenVINO EP: Option '" + block_and_advise_entry.first +
+                              "' cannot be set when using AppendExecutionProvider_V2. " +
+                              "It can instead be enabled by a load_config key / value pair. For example: " +
+                              block_and_advise_entry.second;
+        return Status(common::ONNXRUNTIME, ORT_INVALID_ARGUMENT, message);
+      }
+    }
+
+    // For the rest of the disallowed provider options, give a generic error message.
+    const std::vector<std::string> blocked_provider_keys = {
+      "device_type", "device_id", "device_luid", "context", "num_of_threads", "disable_dynamic_shapes"};
 
     for (const auto& key : blocked_provider_keys) {
       if (provider_options.find(key) != provider_options.end()) {
         return Status(common::ONNXRUNTIME, ORT_INVALID_ARGUMENT,
-                      "OpenVINO EP: Option '" + key + "' cannot be set explicitly when using AppendExecutionProvider_V2.");
+                      "OpenVINO EP: Option '" + key + "' cannot be set when using AppendExecutionProvider_V2.");
       }
     }
 
diff --git a/onnxruntime/test/providers/openvino/openvino_plugin.cc b/onnxruntime/test/providers/openvino/openvino_plugin.cc
index bf2cb698a8aa2..5abca55820a24 100644
--- a/onnxruntime/test/providers/openvino/openvino_plugin.cc
+++ b/onnxruntime/test/providers/openvino/openvino_plugin.cc
@@ -137,6 +137,22 @@ TEST_F(OrtEpLibraryOv, MetaDevicesAvailable) {
   }
 }
 
+TEST_F(OrtEpLibraryOv, RunSessionWithAllAUTODevices) {
+  auto ep_devices = ort_env->GetEpDevices();
+  std::vector<Ort::ConstEpDevice> matching_devices;
+
+  for (const auto& device : ep_devices) {
+    std::string ep_name = device.EpName();
+    if (ep_name.find(registration_name) != std::string::npos &&
+        (ep_name == registration_name + ".AUTO")) {
+      matching_devices.push_back(device);
+    }
+  }
+  Ort::SessionOptions session_options;
+  session_options.AppendExecutionProvider_V2(*ort_env, matching_devices, std::unordered_map<std::string, std::string>{});
+  Ort::Session session(*ort_env, ORT_TSTR("testdata/mul_1.onnx"), session_options);
+}
+
 TEST_F(OrtEpLibraryOv, PluginEp_AppendV2_MulInference) {
   auto plugin_ep_device = GetOvCpuEpDevice();
   ASSERT_NE(plugin_ep_device, nullptr);
@@ -178,6 +194,31 @@ TEST_F(OrtEpLibraryOv, PluginEp_AppendV2_cpu_epctx_variants) {
   }
 }
 
+TEST_F(OrtEpLibraryOv, PluginEp_CheckV2DisallowedProviderOptions) {
+  auto plugin_ep_device = GetOvCpuEpDevice();
+  ASSERT_NE(plugin_ep_device, nullptr);
+  std::vector<std::unordered_map<std::string, std::string>> disallowed_provider_option_examples = {
+      {{"device_type", "CPU"}},
+      {{"device_id", "CPU"}},
+      {{"device_luid", "1234"}},
+      {{"cache_dir", "cache"}},
+      {{"precision", "F32"}},
+      {{"context", "4"}},
+      {{"num_of_threads", "1"}},
+      {{"model_priority", "DEFAULT"}},
+      {{"num_streams", "1"}},
+      {{"enable_opencl_throttling", "true"}},
+      {{"enable_qdq_optimizer", "true"}},
+      {{"disable_dynamic_shapes", "true"}},
+  };
+  for (auto& example : disallowed_provider_option_examples) {
+    EXPECT_THROW({
+    Ort::SessionOptions session_options;
+    session_options.AppendExecutionProvider_V2(*ort_env, std::vector<Ort::ConstEpDevice>{plugin_ep_device}, example);
+    Ort::Session session(*ort_env, ORT_TSTR("testdata/mul_1.onnx"), session_options); }, Ort::Exception);
+  }
+}
+
 TEST_F(OrtEpLibraryOv, GenerateEpContextEmbedded) {
   GenerateEpContextOnPluginPath(ORT_TSTR("mul_1_ctx_cpu_embed1.onnx"), true);
 }