diff --git a/health/2.1/README.md b/health/2.1/README.md
new file mode 100644
index 0000000..5a19d7b
--- /dev/null
+++ b/health/2.1/README.md
@@ -0,0 +1,245 @@
+# Implementing Health 2.1 HAL
+
+1. Install common binderized service. The binderized service `dlopen()`s
+   passthrough implementations on the device, so there is no need to write
+   your own.
+
+    ```mk
+    # Install default binderized implementation to vendor.
+    PRODUCT_PACKAGES += android.hardware.health@2.1-service
+    ```
+
+1. Delete existing VINTF manifest entry. Search for `android.hardware.health` in
+   your device manifest, and delete the whole `<hal>` entry for older versions
+   of the HAL. Instead, when `android.hardware.health@2.1-service` is installed,
+   a VINTF manifest fragment is installed to `/vendor/etc/vintf`, so there is
+   no need to manually specify it in your device manifest. See
+   [Manifest fragments](https://source.android.com/devices/architecture/vintf/objects#manifest-fragments)
+   for details.
+
+1. Install the proper passthrough implemetation.
+
+    1. If you want to use default implementation:
+
+        ```mk
+        # Install default passthrough implementation to vendor.
+        PRODUCT_PACKAGES += android.hardware.health@2.1-impl
+        ```
+
+        You are done. Otherwise, go to the next step.
+
+    1. If you want to write your own implementation,
+
+        1. Copy skeleton implementation from the [appendix](#impl).
+
+        1. Modify the implementation to suit your needs.
+
+            * If you have a board or device specific `libhealthd`, see
+              [Upgrading with  a customized libhealthd](#update-from-1-0).
+            * If you are upgrading from 1.0 health HAL, see
+              [Upgrading from Health HAL 1.0](#update-from-1-0).
+            * If you are upgrading from a customized 2.0 health HAL
+              implementation, See
+              [Upgrading from Health HAL 2.0](#update-from-2-0).
+
+        1. [Update necessary SELinux permissions](#selinux).
+
+        1. [Fix `/charger` symlink](#charger-symlink).
+
+# Upgrading with a customized libhealthd or from Health HAL 1.0 {#update-from-1-0}
+
+`libhealthd` contains two functions: `healthd_board_init()` and
+`healthd_board_battery_update()`. Similarly, Health HAL 1.0 contains `init()`
+and `update()`, with an additional `energyCounter()` function.
+
+* `healthd_board_init()` / `@1.0::IHealth.init()` should be called before
+  passing the `healthd_config` struct to your `HealthImpl` class. See
+  `HIDL_FETCH_IHealth` in [`HealthImpl.cpp`](#health_impl_cpp).
+
+* `healthd_board_battery_update()` / `@1.0::IHealth.update()` should be called
+  in `HealthImpl::UpdateHealthInfo()`. Example:
+
+  ```c++
+  void HealthImpl::UpdateHealthInfo(HealthInfo* health_info) {
+      struct BatteryProperties props;
+      convertFromHealthInfo(health_info->legacy.legacy, &props);
+      healthd_board_battery_update(&props);
+      convertToHealthInfo(&props, health_info->legacy.legacy);
+  }
+  ```
+  For efficiency, you should move code in `healthd_board_battery_update` to
+  `HealthImpl::UpdateHealthInfo` and modify `health_info` directly to avoid
+  conversion to `BatteryProperties`.
+
+* Code for `@1.0::IHealth.energyCounter()` should be moved to
+  `HealthImpl::getEnergyCounter()`. Example:
+
+  ```c++
+  Return<void> Health::getEnergyCounter(getEnergyCounter_cb _hidl_cb) {
+      int64_t energy = /* ... */;
+      _hidl_cb(Result::SUCCESS, energy);
+      return Void();
+  }
+  ```
+
+# Upgrading from Health HAL 2.0 {#update-from-2-0}
+
+* If you have implemented `healthd_board_init()` and/or
+  `healthd_board_battery_update()` (instead of using `libhealthd.default`),
+  see [the section above](#update-from-1-0)
+  for instructions to convert them.
+
+* If you have implemented `get_storage_info()` and/or `get_disk_stats()`
+  (instead of using libhealthstoragedefault), implement `HealthImpl::getDiskStats`
+  and/or `HealthImpl::getStorageInfo` directly. There is no need to override
+  `HealthImpl::getHealthInfo` or `HealthImpl::getHealthInfo_2_1` because they call
+  `getDiskStats` and `getStorageInfo` to retrieve storage information.
+
+# Update necessary SELinux permissions {#selinux}
+
+For example (replace `<device>` with the device name):
+```
+# device/<manufacturer>/<device>/sepolicy/vendor/hal_health_default.te
+# Add device specific permissions to hal_health_default domain, especially
+# if a device-specific libhealthd is used and/or device-specific storage related
+# APIs are implemented.
+```
+
+# Fix `/charger` symlink {#charger-symlink}
+If you are using `/charger` in your `init.rc` scripts, it is recommended
+(required for devices running in Android R) that the path is changed to
+`/system/bin/charger` instead.
+
+Search for `service charger` in your device configuration directory to see if
+this change applies to your device. Below is an example of how the script should
+look like:
+
+```
+service charger /system/bin/charger
+    class charger
+    user system
+    group system wakelock input
+    capabilities SYS_BOOT
+    file /dev/kmsg w
+    file /sys/fs/pstore/console-ramoops-0 r
+    file /sys/fs/pstore/console-ramoops r
+    file /proc/last_kmsg r
+```
+
+# Appendix: sample code for the implementation {#impl}
+
+## `device/<manufacturer>/<device>/health/Android.bp` {#android_bp}
+
+```bp
+cc_library_shared {
+    name: "android.hardware.health@2.1-impl-<device>",
+    stem: "android.hardware.health@2.0-impl-2.1-<device>",
+
+    // Install to vendor and recovery.
+    proprietary: true,
+    recovery_available: true,
+
+    relative_install_path: "hw",
+
+    shared_libs: [
+        "libbase",
+        "libcutils",
+        "libhidlbase",
+        "liblog",
+        "libutils",
+        "android.hardware.health@2.1",
+        "android.hardware.health@2.0",
+    ],
+
+    static_libs: [
+        "android.hardware.health@1.0-convert",
+        "libbatterymonitor",
+        "libhealthloop",
+        "libhealth2impl",
+        // "libhealthd.<device>"
+    ],
+
+    srcs: [
+        "HealthImpl.cpp",
+    ],
+
+    // No vintf_fragments because both -impl and -service should have been
+    // installed.
+}
+```
+
+## `device/<manufacturer>/<device>/health/HealthImpl.cpp` {#health_impl_cpp}
+
+```c++
+#include <memory>
+#include <string_view>
+
+#include <health/utils.h>
+#include <health2impl/Health.h>
+#include <hidl/Status.h>
+
+using ::android::sp;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::hardware::health::InitHealthdConfig;
+using ::android::hardware::health::V2_1::IHealth;
+using ::android::hidl::base::V1_0::IBase;
+
+using namespace std::literals;
+
+namespace android {
+namespace hardware {
+namespace health {
+namespace V2_1 {
+namespace implementation {
+
+// android::hardware::health::V2_1::implementation::Health implements most
+// defaults. Uncomment functions that you need to override.
+class HealthImpl : public Health {
+  public:
+    HealthImpl(std::unique_ptr<healthd_config>&& config)
+        : Health(std::move(config)) {}
+
+    // A subclass can override this if these information should be retrieved
+    // differently.
+    // Return<void> getChargeCounter(getChargeCounter_cb _hidl_cb) override;
+    // Return<void> getCurrentNow(getCurrentNow_cb _hidl_cb) override;
+    // Return<void> getCurrentAverage(getCurrentAverage_cb _hidl_cb) override;
+    // Return<void> getCapacity(getCapacity_cb _hidl_cb) override;
+    // Return<void> getEnergyCounter(getEnergyCounter_cb _hidl_cb) override;
+    // Return<void> getChargeStatus(getChargeStatus_cb _hidl_cb) override;
+    // Return<void> getStorageInfo(getStorageInfo_cb _hidl_cb) override;
+    // Return<void> getDiskStats(getDiskStats_cb _hidl_cb) override;
+    // Return<void> getHealthInfo(getHealthInfo_cb _hidl_cb) override;
+
+    // Functions introduced in Health HAL 2.1.
+    // Return<void> getHealthConfig(getHealthConfig_cb _hidl_cb) override;
+    // Return<void> getHealthInfo_2_1(getHealthInfo_2_1_cb _hidl_cb) override;
+    // Return<void> shouldKeepScreenOn(shouldKeepScreenOn_cb _hidl_cb) override;
+
+  protected:
+    // A subclass can override this to modify any health info object before
+    // returning to clients. This is similar to healthd_board_battery_update().
+    // By default, it does nothing.
+    // void UpdateHealthInfo(HealthInfo* health_info) override;
+};
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace health
+}  // namespace hardware
+}  // namespace android
+
+extern "C" IHealth* HIDL_FETCH_IHealth(const char* instance) {
+    using ::android::hardware::health::V2_1::implementation::HealthImpl;
+    if (instance != "default"sv) {
+        return nullptr;
+    }
+    auto config = std::make_unique<healthd_config>();
+    InitHealthdConfig(config.get());
+
+    // healthd_board_init(config.get());
+
+    return new HealthImpl(std::move(config));
+}
+```
diff --git a/health/2.1/default/Android.bp b/health/2.1/default/Android.bp
new file mode 100644
index 0000000..3649853
--- /dev/null
+++ b/health/2.1/default/Android.bp
@@ -0,0 +1,81 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// 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.
+
+cc_defaults {
+    name: "android.hardware.health@2.1-impl-defaults",
+    relative_install_path: "hw",
+
+    shared_libs: [
+        "libbase",
+        "libcutils",
+        "libhidlbase",
+        "liblog",
+        "libutils",
+        "android.hardware.health@2.1",
+        "android.hardware.health@2.0",
+    ],
+
+    static_libs: [
+        "android.hardware.health@1.0-convert",
+        "libbatterymonitor",
+        "libhealthloop",
+        "libhealth2impl",
+    ],
+}
+
+// Default passthrough implementation of the health@2.1 HAL.
+// Passhtrough implementations of the health@2.1 HAL must be installed in
+// vendor in order to support charger.
+// Passhtrough implementations of the health@2.1 HAL must be installed in
+// recovery in order to allow recovery to check battery status.
+// See README.md for details.
+cc_library_shared {
+    name: "android.hardware.health@2.1-impl",
+    stem: "android.hardware.health@2.0-impl-2.1",
+
+    // Only vendor and recovery variants are allowed, not core.
+    vendor: true,
+    recovery_available: true,
+
+    defaults: ["android.hardware.health@2.1-impl-defaults"],
+
+    srcs: [
+        "impl.cpp",
+    ],
+
+    // No vintf_fragments because both -impl and -service should have been
+    // installed.
+}
+
+// Default binderized service of the health@2.1 HAL.
+// This binderized implementation dlopen()s the passthrough implementation,
+// so there is no need to implement your own.
+cc_binary {
+    name: "android.hardware.health@2.1-service",
+    vendor: true,
+    defaults: ["android.hardware.health@2.1-impl-defaults"],
+    init_rc: ["android.hardware.health@2.1-service.rc"],
+
+    srcs: [
+        "service.cpp",
+    ],
+
+    vintf_fragments: [
+        "android.hardware.health@2.1.xml"
+    ],
+
+    overrides: [
+        "healthd",
+    ],
+}
diff --git a/health/2.1/default/android.hardware.health@2.1-service.rc b/health/2.1/default/android.hardware.health@2.1-service.rc
new file mode 100644
index 0000000..917f1c2
--- /dev/null
+++ b/health/2.1/default/android.hardware.health@2.1-service.rc
@@ -0,0 +1,6 @@
+service health-hal-2-1 /vendor/bin/hw/android.hardware.health@2.1-service
+    class hal
+    user system
+    group system
+    capabilities WAKE_ALARM
+    file /dev/kmsg w
diff --git a/health/2.1/default/android.hardware.health@2.1.xml b/health/2.1/default/android.hardware.health@2.1.xml
new file mode 100644
index 0000000..34fdca6
--- /dev/null
+++ b/health/2.1/default/android.hardware.health@2.1.xml
@@ -0,0 +1,7 @@
+<manifest version="1.0" type="device">
+    <hal format="hidl">
+        <name>android.hardware.health</name>
+        <transport>hwbinder</transport>
+        <fqname>@2.1::IHealth/default</fqname>
+    </hal>
+</manifest>
diff --git a/health/2.1/default/impl.cpp b/health/2.1/default/impl.cpp
new file mode 100644
index 0000000..7389a21
--- /dev/null
+++ b/health/2.1/default/impl.cpp
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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 <memory>
+#include <string_view>
+
+#include <health/utils.h>
+#include <health2impl/Health.h>
+
+using ::android::sp;
+using ::android::hardware::health::InitHealthdConfig;
+using ::android::hardware::health::V2_1::IHealth;
+using ::android::hardware::health::V2_1::implementation::Health;
+
+using namespace std::literals;
+
+// Passthrough implementation of the health service. Use default configuration.
+// It does not invoke callbacks unless update() is called explicitly. No
+// background thread is spawned to handle callbacks.
+//
+// The passthrough implementation is only allowed in recovery mode, charger, and
+// opened by the hwbinder service.
+// If Android is booted normally, the hwbinder service is used instead.
+//
+// This implementation only implements the "default" instance. It rejects
+// other instance names.
+// Note that the Android framework only reads values from the "default"
+// health HAL 2.1 instance.
+extern "C" IHealth* HIDL_FETCH_IHealth(const char* instance) {
+    if (instance != "default"sv) {
+        return nullptr;
+    }
+    auto config = std::make_unique<healthd_config>();
+    InitHealthdConfig(config.get());
+
+    // This implementation uses default config. If you want to customize it
+    // (e.g. with healthd_board_init), do it here.
+
+    return new Health(std::move(config));
+}
diff --git a/health/2.1/default/service.cpp b/health/2.1/default/service.cpp
new file mode 100644
index 0000000..f8334c5
--- /dev/null
+++ b/health/2.1/default/service.cpp
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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.
+ */
+#define LOG_TAG "android.hardware.health@2.1-service"
+
+#include <android-base/logging.h>
+#include <android/hardware/health/2.1/IHealth.h>
+#include <health2impl/BinderHealth.h>
+
+using ::android::sp;
+using ::android::hardware::health::V2_1::IHealth;
+using ::android::hardware::health::V2_1::implementation::BinderHealth;
+using IHealth_2_0 = ::android::hardware::health::V2_0::IHealth;
+
+static constexpr const char* gInstanceName = "default";
+
+int main(int /* argc */, char* /* argv */[]) {
+    sp<IHealth> passthrough =
+            IHealth::castFrom(IHealth_2_0::getService(gInstanceName, true /* getStub */));
+    CHECK(passthrough != nullptr)
+            << "Cannot find passthrough implementation of health 2.1 HAL for instance "
+            << gInstanceName;
+    sp<BinderHealth> binder = new BinderHealth(gInstanceName, passthrough);
+    return binder->StartLoop();
+}