diff --git a/gnss/1.1/vts/functional/gnss_hal_test.cpp b/gnss/1.1/vts/functional/gnss_hal_test.cpp
index 24de37d..88fbff8 100644
--- a/gnss/1.1/vts/functional/gnss_hal_test.cpp
+++ b/gnss/1.1/vts/functional/gnss_hal_test.cpp
@@ -172,7 +172,14 @@
                 hasGnssHalVersion_2_0 = registered.size() != 0;
             });
 
-    return hasGnssHalVersion_1_1 && !hasGnssHalVersion_2_0;
+    bool hasGnssHalVersion_2_1 = false;
+    manager->listManifestByInterface(
+            "android.hardware.gnss@2.1::IGnss",
+            [&hasGnssHalVersion_2_1](const hidl_vec<hidl_string>& registered) {
+                hasGnssHalVersion_2_1 = registered.size() != 0;
+            });
+
+    return hasGnssHalVersion_1_1 && !hasGnssHalVersion_2_0 && !hasGnssHalVersion_2_1;
 }
 
 GnssConstellationType GnssHalTest::startLocationAndGetNonGpsConstellation(
diff --git a/gnss/2.0/vts/functional/gnss_hal_test.cpp b/gnss/2.0/vts/functional/gnss_hal_test.cpp
index 8ca3f68..b3a3203 100644
--- a/gnss/2.0/vts/functional/gnss_hal_test.cpp
+++ b/gnss/2.0/vts/functional/gnss_hal_test.cpp
@@ -16,11 +16,14 @@
 
 #define LOG_TAG "GnssHalTest"
 
+#include <android/hidl/manager/1.2/IServiceManager.h>
 #include <gnss_hal_test.h>
+#include <gtest/gtest.h>
+#include <hidl/ServiceManagement.h>
 #include <chrono>
 #include "Utils.h"
 
-#include <gtest/gtest.h>
+using ::android::hardware::hidl_string;
 
 using ::android::hardware::gnss::common::Utils;
 
@@ -99,7 +102,6 @@
 
     EXPECT_TRUE(result.isOk());
     EXPECT_TRUE(result);
-
     /*
      * GnssLocationProvider support of AGPS SUPL & XtraDownloader is not available in VTS,
      * so allow time to demodulate ephemeris over the air.
@@ -148,6 +150,27 @@
     }
 }
 
+bool GnssHalTest::IsGnssHalVersion_2_0() const {
+    using ::android::hidl::manager::V1_2::IServiceManager;
+    sp<IServiceManager> manager = ::android::hardware::defaultServiceManager1_2();
+
+    bool hasGnssHalVersion_2_0 = false;
+    manager->listManifestByInterface(
+            "android.hardware.gnss@2.0::IGnss",
+            [&hasGnssHalVersion_2_0](const hidl_vec<hidl_string>& registered) {
+                hasGnssHalVersion_2_0 = registered.size() != 0;
+            });
+
+    bool hasGnssHalVersion_2_1 = false;
+    manager->listManifestByInterface(
+            "android.hardware.gnss@2.1::IGnss",
+            [&hasGnssHalVersion_2_1](const hidl_vec<hidl_string>& registered) {
+                hasGnssHalVersion_2_1 = registered.size() != 0;
+            });
+
+    return hasGnssHalVersion_2_0 && !hasGnssHalVersion_2_1;
+}
+
 GnssHalTest::GnssCallback::GnssCallback()
     : info_cbq_("system_info"),
       name_cbq_("name"),
diff --git a/gnss/2.0/vts/functional/gnss_hal_test.h b/gnss/2.0/vts/functional/gnss_hal_test.h
index 4f7b87a..55dc1bc 100644
--- a/gnss/2.0/vts/functional/gnss_hal_test.h
+++ b/gnss/2.0/vts/functional/gnss_hal_test.h
@@ -181,6 +181,12 @@
     void StopAndClearLocations();
 
     /*
+     * IsGnssHalVersion_2_0:
+     * returns  true if the GNSS HAL version is exactly 2.0.
+     */
+    bool IsGnssHalVersion_2_0() const;
+
+    /*
      * SetPositionMode:
      * Helper function to set positioning mode and verify output
      */
diff --git a/gnss/2.0/vts/functional/gnss_hal_test_cases.cpp b/gnss/2.0/vts/functional/gnss_hal_test_cases.cpp
index c442cc6..0fa08b9 100644
--- a/gnss/2.0/vts/functional/gnss_hal_test_cases.cpp
+++ b/gnss/2.0/vts/functional/gnss_hal_test_cases.cpp
@@ -182,6 +182,10 @@
  * 3. state is valid.
  */
 TEST_P(GnssHalTest, TestGnssMeasurementFields) {
+    if (!IsGnssHalVersion_2_0()) {
+        ALOGI("Test GnssMeasurementFields skipped. GNSS HAL version is greater than 2.0.");
+        return;
+    }
     const int kFirstGnssMeasurementTimeoutSeconds = 10;
 
     auto gnssMeasurement = gnss_hal_->getExtensionGnssMeasurement_2_0();
@@ -464,7 +468,7 @@
         }
         EXPECT_LE(location_called_count, i);
         if (location_called_count != i) {
-            ALOGW("GetLocationLowPower test - not enough locations received. %d vs. %d expected ",
+            ALOGW("GetLocationLowPower test - too many locations received. %d vs. %d expected ",
                   location_called_count, i);
         }
 
@@ -601,6 +605,11 @@
  * formerly strongest satellite
  */
 TEST_P(GnssHalTest, BlacklistIndividualSatellites) {
+    if (!IsGnssHalVersion_2_0()) {
+        ALOGI("Test BlacklistIndividualSatellites skipped. GNSS HAL version is greater than 2.0.");
+        return;
+    }
+
     if (!(gnss_cb_->last_capabilities_ & IGnssCallback::Capabilities::SATELLITE_BLACKLIST)) {
         ALOGI("Test BlacklistIndividualSatellites skipped. SATELLITE_BLACKLIST capability"
               " not supported.");
@@ -746,6 +755,11 @@
  * 4a & b) Clean up by turning off location, and send in empty blacklist.
  */
 TEST_P(GnssHalTest, BlacklistConstellation) {
+    if (!IsGnssHalVersion_2_0()) {
+        ALOGI("Test BlacklistConstellation skipped. GNSS HAL version is greater than 2.0.");
+        return;
+    }
+
     if (!(gnss_cb_->last_capabilities_ & IGnssCallback::Capabilities::SATELLITE_BLACKLIST)) {
         ALOGI("Test BlacklistConstellation skipped. SATELLITE_BLACKLIST capability not supported.");
         return;
diff --git a/gnss/2.1/default/Android.bp b/gnss/2.1/default/Android.bp
index 57233aa..7ef9990 100644
--- a/gnss/2.1/default/Android.bp
+++ b/gnss/2.1/default/Android.bp
@@ -23,8 +23,9 @@
     srcs: [
         "Gnss.cpp",
         "GnssMeasurement.cpp",
+        "GnssMeasurementCorrections.cpp",
         "GnssConfiguration.cpp",
-        "service.cpp"
+        "service.cpp",
     ],
     shared_libs: [
         "libhidlbase",
diff --git a/gnss/2.1/default/Gnss.cpp b/gnss/2.1/default/Gnss.cpp
index fd7a9df..6b61a82 100644
--- a/gnss/2.1/default/Gnss.cpp
+++ b/gnss/2.1/default/Gnss.cpp
@@ -18,11 +18,14 @@
 
 #include "Gnss.h"
 #include "GnssMeasurement.h"
+#include "GnssMeasurementCorrections.h"
 #include "Utils.h"
 
 #include <log/log.h>
 
 using ::android::hardware::gnss::common::Utils;
+using ::android::hardware::gnss::measurement_corrections::V1_0::implementation::
+        GnssMeasurementCorrections;
 
 namespace android {
 namespace hardware {
@@ -87,7 +90,8 @@
 }
 
 Return<void> Gnss::cleanup() {
-    // TODO implement
+    sGnssCallback_2_1 = nullptr;
+    sGnssCallback_2_0 = nullptr;
     return Void();
 }
 
@@ -170,8 +174,9 @@
 }
 
 Return<bool> Gnss::setPositionMode_1_1(V1_0::IGnss::GnssPositionMode,
-                                       V1_0::IGnss::GnssPositionRecurrence, uint32_t, uint32_t,
-                                       uint32_t, bool) {
+                                       V1_0::IGnss::GnssPositionRecurrence, uint32_t minIntervalMs,
+                                       uint32_t, uint32_t, bool) {
+    mMinIntervalMs = minIntervalMs;
     return true;
 }
 
@@ -215,7 +220,7 @@
         ALOGE("%s: Unable to invoke callback", __func__);
     }
 
-    auto gnssName = "Google Mock GNSS Implementation v2.0";
+    auto gnssName = "Google Mock GNSS Implementation v2.1";
     ret = sGnssCallback_2_0->gnssNameCb(gnssName);
     if (!ret.isOk()) {
         ALOGE("%s: Unable to invoke callback", __func__);
@@ -251,8 +256,8 @@
 
 Return<sp<measurement_corrections::V1_0::IMeasurementCorrections>>
 Gnss::getExtensionMeasurementCorrections() {
-    // TODO implement
-    return ::android::sp<measurement_corrections::V1_0::IMeasurementCorrections>{};
+    ALOGD("Gnss::getExtensionMeasurementCorrections()");
+    return new GnssMeasurementCorrections();
 }
 
 Return<sp<visibility_control::V1_0::IGnssVisibilityControl>> Gnss::getExtensionVisibilityControl() {
@@ -266,7 +271,7 @@
 }
 
 Return<bool> Gnss::injectBestLocation_2_0(const V2_0::GnssLocation&) {
-    // TODO implement
+    // TODO(b/124012850): Implement function.
     return bool{};
 }
 
@@ -316,6 +321,7 @@
 
 void Gnss::reportSvStatus(const hidl_vec<GnssSvInfo>& svInfoList) const {
     std::unique_lock<std::mutex> lock(mMutex);
+    // TODO(skz): update this to call 2_0 callback if non-null
     if (sGnssCallback_2_1 == nullptr) {
         ALOGE("%s: sGnssCallback v2.1 is null.", __func__);
         return;
@@ -328,13 +334,20 @@
 
 void Gnss::reportLocation(const V2_0::GnssLocation& location) const {
     std::unique_lock<std::mutex> lock(mMutex);
-    if (sGnssCallback_2_1 == nullptr) {
-        ALOGE("%s: sGnssCallback v2.1 is null.", __func__);
+    if (sGnssCallback_2_1 != nullptr) {
+        auto ret = sGnssCallback_2_1->gnssLocationCb_2_0(location);
+        if (!ret.isOk()) {
+            ALOGE("%s: Unable to invoke callback v2.1", __func__);
+        }
         return;
     }
-    auto ret = sGnssCallback_2_1->gnssLocationCb_2_0(location);
+    if (sGnssCallback_2_0 == nullptr) {
+        ALOGE("%s: No non-null callback", __func__);
+        return;
+    }
+    auto ret = sGnssCallback_2_0->gnssLocationCb_2_0(location);
     if (!ret.isOk()) {
-        ALOGE("%s: Unable to invoke callback", __func__);
+        ALOGE("%s: Unable to invoke callback v2.0", __func__);
     }
 }
 
diff --git a/gnss/2.1/default/GnssMeasurement.cpp b/gnss/2.1/default/GnssMeasurement.cpp
index ebfa7dd..34e20e5 100644
--- a/gnss/2.1/default/GnssMeasurement.cpp
+++ b/gnss/2.1/default/GnssMeasurement.cpp
@@ -29,7 +29,8 @@
 namespace V2_1 {
 namespace implementation {
 
-sp<V2_1::IGnssMeasurementCallback> GnssMeasurement::sCallback = nullptr;
+sp<V2_1::IGnssMeasurementCallback> GnssMeasurement::sCallback_2_1 = nullptr;
+sp<V2_0::IGnssMeasurementCallback> GnssMeasurement::sCallback_2_0 = nullptr;
 
 GnssMeasurement::GnssMeasurement() : mMinIntervalMillis(1000) {}
 
@@ -48,7 +49,8 @@
     ALOGD("close");
     std::unique_lock<std::mutex> lock(mMutex);
     stop();
-    sCallback = nullptr;
+    sCallback_2_1 = nullptr;
+    sCallback_2_0 = nullptr;
     return Void();
 }
 
@@ -61,9 +63,18 @@
 
 // Methods from V2_0::IGnssMeasurement follow.
 Return<V1_0::IGnssMeasurement::GnssMeasurementStatus> GnssMeasurement::setCallback_2_0(
-        const sp<V2_0::IGnssMeasurementCallback>&, bool) {
-    // TODO implement
-    return V1_0::IGnssMeasurement::GnssMeasurementStatus{};
+        const sp<V2_0::IGnssMeasurementCallback>& callback, bool) {
+    ALOGD("setCallback_2_0");
+    std::unique_lock<std::mutex> lock(mMutex);
+    sCallback_2_0 = callback;
+
+    if (mIsActive) {
+        ALOGW("GnssMeasurement callback already set. Resetting the callback...");
+        stop();
+    }
+    start();
+
+    return V1_0::IGnssMeasurement::GnssMeasurementStatus::SUCCESS;
 }
 
 // Methods from V2_1::IGnssMeasurement follow.
@@ -71,7 +82,7 @@
         const sp<V2_1::IGnssMeasurementCallback>& callback, bool) {
     ALOGD("setCallback_2_1");
     std::unique_lock<std::mutex> lock(mMutex);
-    sCallback = callback;
+    sCallback_2_1 = callback;
 
     if (mIsActive) {
         ALOGW("GnssMeasurement callback already set. Resetting the callback...");
@@ -87,8 +98,13 @@
     mIsActive = true;
     mThread = std::thread([this]() {
         while (mIsActive == true) {
-            auto measurement = Utils::getMockMeasurementV2_1();
-            this->reportMeasurement(measurement);
+            if (sCallback_2_1 != nullptr) {
+                auto measurement = Utils::getMockMeasurementV2_1();
+                this->reportMeasurement(measurement);
+            } else {
+                auto measurement = Utils::getMockMeasurementV2_0();
+                this->reportMeasurement(measurement);
+            }
 
             std::this_thread::sleep_for(std::chrono::milliseconds(mMinIntervalMillis));
         }
@@ -103,14 +119,27 @@
     }
 }
 
+void GnssMeasurement::reportMeasurement(const GnssDataV2_0& data) {
+    ALOGD("reportMeasurement()");
+    std::unique_lock<std::mutex> lock(mMutex);
+    if (sCallback_2_0 == nullptr) {
+        ALOGE("%s: GnssMeasurement::sCallback_2_0 is null.", __func__);
+        return;
+    }
+    auto ret = sCallback_2_0->gnssMeasurementCb_2_0(data);
+    if (!ret.isOk()) {
+        ALOGE("%s: Unable to invoke callback", __func__);
+    }
+}
+
 void GnssMeasurement::reportMeasurement(const GnssDataV2_1& data) {
     ALOGD("reportMeasurement()");
     std::unique_lock<std::mutex> lock(mMutex);
-    if (sCallback == nullptr) {
-        ALOGE("%s: GnssMeasurement::sCallback is null.", __func__);
+    if (sCallback_2_1 == nullptr) {
+        ALOGE("%s: GnssMeasurement::sCallback_2_1 is null.", __func__);
         return;
     }
-    auto ret = sCallback->gnssMeasurementCb_2_1(data);
+    auto ret = sCallback_2_1->gnssMeasurementCb_2_1(data);
     if (!ret.isOk()) {
         ALOGE("%s: Unable to invoke callback", __func__);
     }
diff --git a/gnss/2.1/default/GnssMeasurement.h b/gnss/2.1/default/GnssMeasurement.h
index ee32903..3ed7bc5 100644
--- a/gnss/2.1/default/GnssMeasurement.h
+++ b/gnss/2.1/default/GnssMeasurement.h
@@ -30,6 +30,7 @@
 namespace implementation {
 
 using GnssDataV2_1 = V2_1::IGnssMeasurementCallback::GnssData;
+using GnssDataV2_0 = V2_0::IGnssMeasurementCallback::GnssData;
 
 using ::android::sp;
 using ::android::hardware::hidl_array;
@@ -62,9 +63,11 @@
   private:
     void start();
     void stop();
+    void reportMeasurement(const GnssDataV2_0&);
     void reportMeasurement(const GnssDataV2_1&);
 
-    static sp<IGnssMeasurementCallback> sCallback;
+    static sp<V2_1::IGnssMeasurementCallback> sCallback_2_1;
+    static sp<V2_0::IGnssMeasurementCallback> sCallback_2_0;
     std::atomic<long> mMinIntervalMillis;
     std::atomic<bool> mIsActive;
     std::thread mThread;
diff --git a/gnss/2.1/default/GnssMeasurementCorrections.cpp b/gnss/2.1/default/GnssMeasurementCorrections.cpp
new file mode 100644
index 0000000..2bf5601
--- /dev/null
+++ b/gnss/2.1/default/GnssMeasurementCorrections.cpp
@@ -0,0 +1,75 @@
+/*
+ * 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 "GnssMeasurementCorrections"
+
+#include "GnssMeasurementCorrections.h"
+#include <log/log.h>
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace measurement_corrections {
+namespace V1_0 {
+namespace implementation {
+
+// Methods from V1_0::IMeasurementCorrections follow.
+Return<bool> GnssMeasurementCorrections::setCorrections(const MeasurementCorrections& corrections) {
+    ALOGD("setCorrections");
+    ALOGD("corrections = lat: %f, lng: %f, alt: %f, hUnc: %f, vUnc: %f, toa: %llu, "
+          "satCorrections.size: %d",
+          corrections.latitudeDegrees, corrections.longitudeDegrees, corrections.altitudeMeters,
+          corrections.horizontalPositionUncertaintyMeters,
+          corrections.verticalPositionUncertaintyMeters,
+          static_cast<unsigned long long>(corrections.toaGpsNanosecondsOfWeek),
+          static_cast<int>(corrections.satCorrections.size()));
+    for (auto singleSatCorrection : corrections.satCorrections) {
+        ALOGD("singleSatCorrection = flags: %d, constellation: %d, svid: %d, cfHz: %f, probLos: %f,"
+              " epl: %f, eplUnc: %f",
+              static_cast<int>(singleSatCorrection.singleSatCorrectionFlags),
+              static_cast<int>(singleSatCorrection.constellation),
+              static_cast<int>(singleSatCorrection.svid), singleSatCorrection.carrierFrequencyHz,
+              singleSatCorrection.probSatIsLos, singleSatCorrection.excessPathLengthMeters,
+              singleSatCorrection.excessPathLengthUncertaintyMeters);
+        ALOGD("reflecting plane = lat: %f, lng: %f, alt: %f, azm: %f",
+              singleSatCorrection.reflectingPlane.latitudeDegrees,
+              singleSatCorrection.reflectingPlane.longitudeDegrees,
+              singleSatCorrection.reflectingPlane.altitudeMeters,
+              singleSatCorrection.reflectingPlane.azimuthDegrees);
+    }
+
+    return true;
+}
+
+Return<bool> GnssMeasurementCorrections::setCallback(
+        const sp<V1_0::IMeasurementCorrectionsCallback>& callback) {
+    using Capabilities = V1_0::IMeasurementCorrectionsCallback::Capabilities;
+    auto ret =
+            callback->setCapabilitiesCb(Capabilities::LOS_SATS | Capabilities::EXCESS_PATH_LENGTH |
+                                        Capabilities::REFLECTING_PLANE);
+    if (!ret.isOk()) {
+        ALOGE("%s: Unable to invoke callback", __func__);
+        return false;
+    }
+    return true;
+}
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace measurement_corrections
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android
diff --git a/gnss/2.1/default/GnssMeasurementCorrections.h b/gnss/2.1/default/GnssMeasurementCorrections.h
new file mode 100644
index 0000000..4339bed
--- /dev/null
+++ b/gnss/2.1/default/GnssMeasurementCorrections.h
@@ -0,0 +1,49 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <android/hardware/gnss/measurement_corrections/1.0/IMeasurementCorrections.h>
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+
+namespace android {
+namespace hardware {
+namespace gnss {
+namespace measurement_corrections {
+namespace V1_0 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_memory;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+struct GnssMeasurementCorrections : public IMeasurementCorrections {
+    // Methods from V1_0::IMeasurementCorrections follow.
+    Return<bool> setCorrections(const MeasurementCorrections& corrections) override;
+    Return<bool> setCallback(const sp<V1_0::IMeasurementCorrectionsCallback>& callback) override;
+};
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace measurement_corrections
+}  // namespace gnss
+}  // namespace hardware
+}  // namespace android