diff --git a/test/bm_mode_transition_unittest.cpp b/test/bm_mode_transition_unittest.cpp
new file mode 100644
index 0000000..b39d56c
--- /dev/null
+++ b/test/bm_mode_transition_unittest.cpp
@@ -0,0 +1,120 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#include "bm_config.h"
+
+#include "bmc_mode_enum.hpp"
+#include "errors.hpp"
+#include "file_system_mock.hpp"
+#include "handler.hpp"
+#include "handler_impl.hpp"
+
+#include <filesystem>
+#include <fstream>
+#include <functional>
+#include <memory>
+#include <string>
+
+#include <gtest/gtest.h>
+
+namespace google
+{
+namespace ipmi
+{
+using ::testing::_;
+using ::testing::Eq;
+using ::testing::IsNull;
+using ::testing::NotNull;
+using ::testing::Pointee;
+using ::testing::Return;
+using ::testing::StrEq;
+
+namespace fs = std::filesystem;
+
+class MockFsHandler : public Handler
+{
+  public:
+    MockFsHandler(std::unique_ptr<FileSystemMock> mock,
+                  const std::string& config = "") :
+        Handler(config)
+    {
+        fsPtr_ = move(mock);
+    }
+
+  protected:
+    const std::unique_ptr<FileSystemInterface>& getFs() const override
+    {
+        return fsPtr_;
+    }
+
+  private:
+    std::unique_ptr<FileSystemInterface> fsPtr_;
+};
+
+TEST(BmcModeTransitionTest, DriveCleaningDoneAckFlag)
+{
+    auto fsMockPtr = std::make_unique<FileSystemMock>();
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningDoneAckFlagPath), _))
+        .WillOnce(Return(true));
+
+    MockFsHandler h(move(fsMockPtr));
+    EXPECT_EQ(h.getBmcMode(), static_cast<uint8_t>(BmcMode::BM_MODE));
+}
+
+TEST(BmcModeTransitionTest, DriveCleaningDoneFlag)
+{
+    auto fsMockPtr = std::make_unique<FileSystemMock>();
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningDoneAckFlagPath), _))
+        .WillOnce(Return(false));
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningDoneFlagPath), _))
+        .WillOnce(Return(true));
+    EXPECT_CALL(*fsMockPtr, rename(fs::path(bmDriveCleaningDoneFlagPath),
+                                   fs::path(bmDriveCleaningDoneAckFlagPath), _))
+        .Times(1);
+
+    MockFsHandler h(move(fsMockPtr));
+    EXPECT_EQ(h.getBmcMode(), static_cast<uint8_t>(BmcMode::BM_MODE));
+}
+
+TEST(BmcModeTransitionTest, FirstCleaningFlag)
+{
+    auto fsMockPtr = std::make_unique<FileSystemMock>();
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningDoneAckFlagPath), _))
+        .WillOnce(Return(false));
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningDoneFlagPath), _))
+        .WillOnce(Return(false));
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(BM_SIGNAL_PATH), _))
+        .WillOnce(Return(true));
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningFlagPath), _))
+        .WillOnce(Return(false));
+    EXPECT_CALL(*fsMockPtr, create(StrEq(bmDriveCleaningFlagPath))).Times(1);
+
+    MockFsHandler h(move(fsMockPtr));
+    EXPECT_EQ(h.getBmcMode(), static_cast<uint8_t>(BmcMode::BM_CLEANING_MODE));
+}
+
+TEST(BmcModeTransitionTest, NonBmMode)
+{
+    auto fsMockPtr = std::make_unique<FileSystemMock>();
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningDoneAckFlagPath), _))
+        .WillOnce(Return(false));
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(bmDriveCleaningDoneFlagPath), _))
+        .WillOnce(Return(false));
+    EXPECT_CALL(*fsMockPtr, exists(fs::path(BM_SIGNAL_PATH), _))
+        .WillOnce(Return(false));
+    MockFsHandler h(move(fsMockPtr));
+    EXPECT_EQ(h.getBmcMode(), static_cast<uint8_t>(BmcMode::NON_BM_MODE));
+}
+
+} // namespace ipmi
+} // namespace google
diff --git a/test/file_system_mock.hpp b/test/file_system_mock.hpp
new file mode 100644
index 0000000..de4f38a
--- /dev/null
+++ b/test/file_system_mock.hpp
@@ -0,0 +1,41 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include "file_system_wrapper.hpp"
+
+#include <gmock/gmock.h>
+
+namespace google
+{
+namespace ipmi
+{
+namespace fs = std::filesystem;
+
+class FileSystemMock : public FileSystemInterface
+{
+  public:
+    ~FileSystemMock() = default;
+
+    MOCK_METHOD(bool, exists, (const fs::path&, std::error_code&),
+                (const, override));
+    MOCK_METHOD(void, rename,
+                (const fs::path&, const fs::path&, std::error_code&),
+                (const, override));
+    MOCK_METHOD(void, create, (const char*), (const, override));
+};
+
+} // namespace ipmi
+} // namespace google
diff --git a/test/meson.build b/test/meson.build
index 7fa06c4..c3387dd 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -30,6 +30,7 @@
   'pcie_bifurcation',
   'bmc_mode',
   'linux_boot_done',
+  'bm_mode_transition',
 ]
 
 foreach t : tests