diff --git a/sdk/identity/azure-identity/CHANGELOG.md b/sdk/identity/azure-identity/CHANGELOG.md
index acaf2388eb..1758a39118 100644
--- a/sdk/identity/azure-identity/CHANGELOG.md
+++ b/sdk/identity/azure-identity/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 ### Features Added
 
+- Added Azure App Service API version `2019-08-01` support for `ManagedIdentityCredential`.
+
 ### Breaking Changes
 
 ### Bugs Fixed
diff --git a/sdk/identity/azure-identity/src/managed_identity_credential.cpp b/sdk/identity/azure-identity/src/managed_identity_credential.cpp
index 0d0c9737b6..209dfb8b4f 100644
--- a/sdk/identity/azure-identity/src/managed_identity_credential.cpp
+++ b/sdk/identity/azure-identity/src/managed_identity_credential.cpp
@@ -15,7 +15,8 @@ std::unique_ptr<_detail::ManagedIdentitySource> CreateManagedIdentitySource(
   using namespace Azure::Identity::_detail;
   static std::unique_ptr<ManagedIdentitySource> (*managedIdentitySourceCreate[])(
       std::string const& clientId, TokenCredentialOptions const& options)
-      = {AppServiceManagedIdentitySource::Create,
+      = {AppServiceV2019ManagedIdentitySource::Create,
+         AppServiceV2017ManagedIdentitySource::Create,
          CloudShellManagedIdentitySource::Create,
          AzureArcManagedIdentitySource::Create,
          ImdsManagedIdentitySource::Create};
diff --git a/sdk/identity/azure-identity/src/managed_identity_source.cpp b/sdk/identity/azure-identity/src/managed_identity_source.cpp
index ba0164b9da..56fbf51273 100644
--- a/sdk/identity/azure-identity/src/managed_identity_source.cpp
+++ b/sdk/identity/azure-identity/src/managed_identity_source.cpp
@@ -35,25 +35,30 @@ Azure::Core::Url ManagedIdentitySource::ParseEndpointUrl(
       std::string("The environment variable ") + envVarName + " contains an invalid URL.");
 }
 
+template <typename T>
 std::unique_ptr<ManagedIdentitySource> AppServiceManagedIdentitySource::Create(
     std::string const& clientId,
-    Azure::Core::Credentials::TokenCredentialOptions const& options)
+    Azure::Core::Credentials::TokenCredentialOptions const& options,
+    const char* endpointVarName,
+    const char* secretVarName)
 {
-  constexpr auto EndpointVarName = "MSI_ENDPOINT";
-  auto msiEndpoint = Environment::GetVariable(EndpointVarName);
-  auto msiSecret = Environment::GetVariable("MSI_SECRET");
+  auto msiEndpoint = Environment::GetVariable(endpointVarName);
+  auto msiSecret = Environment::GetVariable(secretVarName);
 
   return (msiEndpoint.empty() || msiSecret.empty())
       ? nullptr
-      : std::unique_ptr<ManagedIdentitySource>(new AppServiceManagedIdentitySource(
-          clientId, options, ParseEndpointUrl(msiEndpoint, EndpointVarName), msiSecret));
+      : std::unique_ptr<ManagedIdentitySource>(
+          new T(clientId, options, ParseEndpointUrl(msiEndpoint, endpointVarName), msiSecret));
 }
 
 AppServiceManagedIdentitySource::AppServiceManagedIdentitySource(
     std::string const& clientId,
     Azure::Core::Credentials::TokenCredentialOptions const& options,
     Azure::Core::Url endpointUrl,
-    std::string const& secret)
+    std::string const& secret,
+    std::string const& apiVersion,
+    std::string const& secretHeaderName,
+    std::string const& clientIdHeaderName)
     : ManagedIdentitySource(options),
       m_request(Azure::Core::Http::HttpMethod::Get, std::move(endpointUrl))
 {
@@ -61,15 +66,15 @@ AppServiceManagedIdentitySource::AppServiceManagedIdentitySource(
     using Azure::Core::Url;
     auto& url = m_request.GetUrl();
 
-    url.AppendQueryParameter("api-version", "2017-09-01");
+    url.AppendQueryParameter("api-version", apiVersion);
 
     if (!clientId.empty())
     {
-      url.AppendQueryParameter("clientid", clientId);
+      url.AppendQueryParameter(clientIdHeaderName, clientId);
     }
   }
 
-  m_request.SetHeader("secret", secret);
+  m_request.SetHeader(secretHeaderName, secret);
 }
 
 Azure::Core::Credentials::AccessToken AppServiceManagedIdentitySource::GetToken(
@@ -90,6 +95,22 @@ Azure::Core::Credentials::AccessToken AppServiceManagedIdentitySource::GetToken(
   });
 }
 
+std::unique_ptr<ManagedIdentitySource> AppServiceV2017ManagedIdentitySource::Create(
+    std::string const& clientId,
+    Core::Credentials::TokenCredentialOptions const& options)
+{
+  return AppServiceManagedIdentitySource::Create<AppServiceV2017ManagedIdentitySource>(
+      clientId, options, "MSI_ENDPOINT", "MSI_SECRET");
+}
+
+std::unique_ptr<ManagedIdentitySource> AppServiceV2019ManagedIdentitySource::Create(
+    std::string const& clientId,
+    Core::Credentials::TokenCredentialOptions const& options)
+{
+  return AppServiceManagedIdentitySource::Create<AppServiceV2019ManagedIdentitySource>(
+      clientId, options, "IDENTITY_ENDPOINT", "IDENTITY_HEADER");
+}
+
 std::unique_ptr<ManagedIdentitySource> CloudShellManagedIdentitySource::Create(
     std::string const& clientId,
     Azure::Core::Credentials::TokenCredentialOptions const& options)
diff --git a/sdk/identity/azure-identity/src/private/managed_identity_source.hpp b/sdk/identity/azure-identity/src/private/managed_identity_source.hpp
index d603d15fa3..40d66fc589 100644
--- a/sdk/identity/azure-identity/src/private/managed_identity_source.hpp
+++ b/sdk/identity/azure-identity/src/private/managed_identity_source.hpp
@@ -28,24 +28,83 @@ namespace Azure { namespace Identity { namespace _detail {
     }
   };
 
-  class AppServiceManagedIdentitySource final : public ManagedIdentitySource {
+  class AppServiceManagedIdentitySource : public ManagedIdentitySource {
   private:
     Core::Http::Request m_request;
 
+  protected:
     explicit AppServiceManagedIdentitySource(
         std::string const& clientId,
         Core::Credentials::TokenCredentialOptions const& options,
         Core::Url endpointUrl,
-        std::string const& secret);
+        std::string const& secret,
+        std::string const& apiVersion,
+        std::string const& secretHeaderName,
+        std::string const& clientIdHeaderName);
 
-  public:
+    template <typename T>
     static std::unique_ptr<ManagedIdentitySource> Create(
         std::string const& clientId,
-        Core::Credentials::TokenCredentialOptions const& options);
+        Core::Credentials::TokenCredentialOptions const& options,
+        const char* endpointVarName,
+        const char* secretVarName);
 
+  public:
     Core::Credentials::AccessToken GetToken(
         Core::Credentials::TokenRequestContext const& tokenRequestContext,
-        Core::Context const& context) const override;
+        Core::Context const& context) const override final;
+  };
+
+  class AppServiceV2017ManagedIdentitySource final : public AppServiceManagedIdentitySource {
+    friend class AppServiceManagedIdentitySource;
+
+  private:
+    explicit AppServiceV2017ManagedIdentitySource(
+        std::string const& clientId,
+        Core::Credentials::TokenCredentialOptions const& options,
+        Core::Url endpointUrl,
+        std::string const& secret)
+        : AppServiceManagedIdentitySource(
+            clientId,
+            options,
+            endpointUrl,
+            secret,
+            "2017-09-01",
+            "secret",
+            "clientid")
+    {
+    }
+
+  public:
+    static std::unique_ptr<ManagedIdentitySource> Create(
+        std::string const& clientId,
+        Core::Credentials::TokenCredentialOptions const& options);
+  };
+
+  class AppServiceV2019ManagedIdentitySource final : public AppServiceManagedIdentitySource {
+    friend class AppServiceManagedIdentitySource;
+
+  private:
+    explicit AppServiceV2019ManagedIdentitySource(
+        std::string const& clientId,
+        Core::Credentials::TokenCredentialOptions const& options,
+        Core::Url endpointUrl,
+        std::string const& secret)
+        : AppServiceManagedIdentitySource(
+            clientId,
+            options,
+            endpointUrl,
+            secret,
+            "2019-08-01",
+            "X-IDENTITY-HEADER",
+            "client_id")
+    {
+    }
+
+  public:
+    static std::unique_ptr<ManagedIdentitySource> Create(
+        std::string const& clientId,
+        Core::Credentials::TokenCredentialOptions const& options);
   };
 
   class CloudShellManagedIdentitySource final : public ManagedIdentitySource {
diff --git a/sdk/identity/azure-identity/test/ut/managed_identity_credential_test.cpp b/sdk/identity/azure-identity/test/ut/managed_identity_credential_test.cpp
index 0166c46a48..27f7d5b80b 100644
--- a/sdk/identity/azure-identity/test/ut/managed_identity_credential_test.cpp
+++ b/sdk/identity/azure-identity/test/ut/managed_identity_credential_test.cpp
@@ -15,7 +15,7 @@ using Azure::Core::Http::HttpStatusCode;
 using Azure::Identity::ManagedIdentityCredential;
 using Azure::Identity::Test::_detail::CredentialTestHelper;
 
-TEST(ManagedIdentityCredential, AppService)
+TEST(ManagedIdentityCredential, AppServiceV2019)
 {
   auto const actual = CredentialTestHelper::SimulateTokenRequest(
       [](auto transport) {
@@ -24,10 +24,250 @@ TEST(ManagedIdentityCredential, AppService)
 
         CredentialTestHelper::EnvironmentOverride const env({
             {"MSI_ENDPOINT", "https://microsoft.com/"},
-            {"MSI_SECRET", "CLIENTSECRET"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", "CLIENTSECRET2"},
+            {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
+        });
+
+        return std::make_unique<ManagedIdentityCredential>(options);
+      },
+      {{{"https://azure.com/.default"}}, {{"https://outlook.com/.default"}}, {{}}},
+      std::vector<std::string>{
+          "{\"expires_in\":3600, \"access_token\":\"ACCESSTOKEN1\"}",
+          "{\"expires_in\":7200, \"access_token\":\"ACCESSTOKEN2\"}",
+          "{\"expires_in\":9999, \"access_token\":\"ACCESSTOKEN3\"}"});
+
+  EXPECT_EQ(actual.Requests.size(), 3U);
+  EXPECT_EQ(actual.Responses.size(), 3U);
+
+  auto const& request0 = actual.Requests.at(0);
+  auto const& request1 = actual.Requests.at(1);
+  auto const& request2 = actual.Requests.at(2);
+
+  auto const& response0 = actual.Responses.at(0);
+  auto const& response1 = actual.Responses.at(1);
+  auto const& response2 = actual.Responses.at(2);
+
+  EXPECT_EQ(request0.HttpMethod, HttpMethod::Get);
+  EXPECT_EQ(request1.HttpMethod, HttpMethod::Get);
+  EXPECT_EQ(request2.HttpMethod, HttpMethod::Get);
+
+  EXPECT_EQ(
+      request0.AbsoluteUrl,
+      "https://visualstudio.com"
+      "?api-version=2019-08-01"
+      "&resource=https%3A%2F%2Fazure.com"); // cspell:disable-line
+
+  EXPECT_EQ(
+      request1.AbsoluteUrl,
+      "https://visualstudio.com"
+      "?api-version=2019-08-01"
+      "&resource=https%3A%2F%2Foutlook.com"); // cspell:disable-line
+
+  EXPECT_EQ(
+      request2.AbsoluteUrl,
+      "https://visualstudio.com"
+      "?api-version=2019-08-01");
+
+  EXPECT_TRUE(request0.Body.empty());
+  EXPECT_TRUE(request1.Body.empty());
+  EXPECT_TRUE(request2.Body.empty());
+
+  {
+    EXPECT_NE(request0.Headers.find("X-IDENTITY-HEADER"), request0.Headers.end());
+    EXPECT_EQ(request0.Headers.at("X-IDENTITY-HEADER"), "CLIENTSECRET2");
+
+    EXPECT_NE(request1.Headers.find("X-IDENTITY-HEADER"), request1.Headers.end());
+    EXPECT_EQ(request1.Headers.at("X-IDENTITY-HEADER"), "CLIENTSECRET2");
+
+    EXPECT_NE(request2.Headers.find("X-IDENTITY-HEADER"), request2.Headers.end());
+    EXPECT_EQ(request2.Headers.at("X-IDENTITY-HEADER"), "CLIENTSECRET2");
+  }
+
+  EXPECT_EQ(response0.AccessToken.Token, "ACCESSTOKEN1");
+  EXPECT_EQ(response1.AccessToken.Token, "ACCESSTOKEN2");
+  EXPECT_EQ(response2.AccessToken.Token, "ACCESSTOKEN3");
+
+  using namespace std::chrono_literals;
+  EXPECT_GE(response0.AccessToken.ExpiresOn, response0.EarliestExpiration + 3600s);
+  EXPECT_LE(response0.AccessToken.ExpiresOn, response0.LatestExpiration + 3600s);
+
+  EXPECT_GE(response1.AccessToken.ExpiresOn, response1.EarliestExpiration + 7200s);
+  EXPECT_LE(response1.AccessToken.ExpiresOn, response1.LatestExpiration + 7200s);
+
+  EXPECT_GE(response2.AccessToken.ExpiresOn, response2.EarliestExpiration + 9999s);
+  EXPECT_LE(response2.AccessToken.ExpiresOn, response2.LatestExpiration + 9999s);
+}
+
+TEST(ManagedIdentityCredential, AppServiceV2019ClientId)
+{
+  auto const actual = CredentialTestHelper::SimulateTokenRequest(
+      [](auto transport) {
+        TokenCredentialOptions options;
+        options.Transport.Transport = transport;
+
+        CredentialTestHelper::EnvironmentOverride const env({
+            {"MSI_ENDPOINT", "https://microsoft.com/"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
+            {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
+            {"IMDS_ENDPOINT", "https://xbox.com/"},
+            {"IDENTITY_HEADER", "CLIENTSECRET2"},
+            {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
+        });
+
+        return std::make_unique<ManagedIdentityCredential>(
+            "fedcba98-7654-3210-0123-456789abcdef", options);
+      },
+      {{{"https://azure.com/.default"}}, {{"https://outlook.com/.default"}}, {{}}},
+      std::vector<std::string>{
+          "{\"expires_in\":3600, \"access_token\":\"ACCESSTOKEN1\"}",
+          "{\"expires_in\":7200, \"access_token\":\"ACCESSTOKEN2\"}",
+          "{\"expires_in\":9999, \"access_token\":\"ACCESSTOKEN3\"}"});
+
+  EXPECT_EQ(actual.Requests.size(), 3U);
+  EXPECT_EQ(actual.Responses.size(), 3U);
+
+  auto const& request0 = actual.Requests.at(0);
+  auto const& request1 = actual.Requests.at(1);
+  auto const& request2 = actual.Requests.at(2);
+
+  auto const& response0 = actual.Responses.at(0);
+  auto const& response1 = actual.Responses.at(1);
+  auto const& response2 = actual.Responses.at(2);
+
+  EXPECT_EQ(request0.HttpMethod, HttpMethod::Get);
+  EXPECT_EQ(request1.HttpMethod, HttpMethod::Get);
+  EXPECT_EQ(request2.HttpMethod, HttpMethod::Get);
+
+  EXPECT_EQ(
+      request0.AbsoluteUrl,
+      "https://visualstudio.com"
+      "?api-version=2019-08-01"
+      "&client_id=fedcba98-7654-3210-0123-456789abcdef"
+      "&resource=https%3A%2F%2Fazure.com"); // cspell:disable-line
+
+  EXPECT_EQ(
+      request1.AbsoluteUrl,
+      "https://visualstudio.com"
+      "?api-version=2019-08-01"
+      "&client_id=fedcba98-7654-3210-0123-456789abcdef"
+      "&resource=https%3A%2F%2Foutlook.com"); // cspell:disable-line
+
+  EXPECT_EQ(
+      request2.AbsoluteUrl,
+      "https://visualstudio.com"
+      "?api-version=2019-08-01"
+      "&client_id=fedcba98-7654-3210-0123-456789abcdef");
+
+  EXPECT_TRUE(request0.Body.empty());
+  EXPECT_TRUE(request1.Body.empty());
+  EXPECT_TRUE(request2.Body.empty());
+
+  {
+    EXPECT_NE(request0.Headers.find("X-IDENTITY-HEADER"), request0.Headers.end());
+    EXPECT_EQ(request0.Headers.at("X-IDENTITY-HEADER"), "CLIENTSECRET2");
+
+    EXPECT_NE(request1.Headers.find("X-IDENTITY-HEADER"), request1.Headers.end());
+    EXPECT_EQ(request1.Headers.at("X-IDENTITY-HEADER"), "CLIENTSECRET2");
+
+    EXPECT_NE(request2.Headers.find("X-IDENTITY-HEADER"), request2.Headers.end());
+    EXPECT_EQ(request2.Headers.at("X-IDENTITY-HEADER"), "CLIENTSECRET2");
+  }
+
+  EXPECT_EQ(response0.AccessToken.Token, "ACCESSTOKEN1");
+  EXPECT_EQ(response1.AccessToken.Token, "ACCESSTOKEN2");
+  EXPECT_EQ(response2.AccessToken.Token, "ACCESSTOKEN3");
+
+  using namespace std::chrono_literals;
+  EXPECT_GE(response0.AccessToken.ExpiresOn, response0.EarliestExpiration + 3600s);
+  EXPECT_LE(response0.AccessToken.ExpiresOn, response0.LatestExpiration + 3600s);
+
+  EXPECT_GE(response1.AccessToken.ExpiresOn, response1.EarliestExpiration + 7200s);
+  EXPECT_LE(response1.AccessToken.ExpiresOn, response1.LatestExpiration + 7200s);
+
+  EXPECT_GE(response2.AccessToken.ExpiresOn, response2.EarliestExpiration + 9999s);
+  EXPECT_LE(response2.AccessToken.ExpiresOn, response2.LatestExpiration + 9999s);
+}
+
+TEST(ManagedIdentityCredential, AppServiceV2019InvalidUrl)
+{
+  using Azure::Core::Credentials::AccessToken;
+  using Azure::Core::Credentials::AuthenticationException;
+
+  using Azure::Core::Credentials::AuthenticationException;
+  static_cast<void>(CredentialTestHelper::SimulateTokenRequest(
+      [](auto transport) {
+        TokenCredentialOptions options;
+        options.Transport.Transport = transport;
+
+        CredentialTestHelper::EnvironmentOverride const env({
+            {"MSI_ENDPOINT", "https://microsoft.com/"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
+            {"IDENTITY_ENDPOINT", "https://visualstudio.com:INVALID/"},
+            {"IMDS_ENDPOINT", "https://xbox.com/"},
+            {"IDENTITY_HEADER", "CLIENTSECRET2"},
+            {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
+        });
+
+        std::unique_ptr<ManagedIdentityCredential const> appServiceV2019ManagedIdentityCredential;
+        EXPECT_THROW(
+            appServiceV2019ManagedIdentityCredential
+            = std::make_unique<ManagedIdentityCredential>(options),
+            AuthenticationException);
+
+        return appServiceV2019ManagedIdentityCredential;
+      },
+      {},
+      {"{\"expires_in\":3600, \"access_token\":\"ACCESSTOKEN1\"}"}));
+}
+
+TEST(ManagedIdentityCredential, AppServiceV2019UnsupportedUrl)
+{
+  using Azure::Core::Credentials::AccessToken;
+  using Azure::Core::Credentials::AuthenticationException;
+
+  using Azure::Core::Credentials::AuthenticationException;
+  static_cast<void>(CredentialTestHelper::SimulateTokenRequest(
+      [](auto transport) {
+        TokenCredentialOptions options;
+        options.Transport.Transport = transport;
+
+        CredentialTestHelper::EnvironmentOverride const env({
+            {"MSI_ENDPOINT", "https://microsoft.com/"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
+            {"IDENTITY_ENDPOINT", "https://visualstudio.com:65536/"},
+            {"IMDS_ENDPOINT", "https://xbox.com/"},
+            {"IDENTITY_HEADER", "CLIENTSECRET2"},
+            {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
+        });
+
+        std::unique_ptr<ManagedIdentityCredential const> appServiceV2019ManagedIdentityCredential;
+        EXPECT_THROW(
+            appServiceV2019ManagedIdentityCredential
+            = std::make_unique<ManagedIdentityCredential>(options),
+            AuthenticationException);
+
+        return appServiceV2019ManagedIdentityCredential;
+      },
+      {},
+      {"{\"expires_in\":3600, \"access_token\":\"ACCESSTOKEN1\"}"}));
+}
+
+TEST(ManagedIdentityCredential, AppServiceV2017)
+{
+  auto const actual = CredentialTestHelper::SimulateTokenRequest(
+      [](auto transport) {
+        TokenCredentialOptions options;
+        options.Transport.Transport = transport;
+
+        CredentialTestHelper::EnvironmentOverride const env({
+            {"MSI_ENDPOINT", "https://microsoft.com/"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
+            {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
+            {"IMDS_ENDPOINT", "https://xbox.com/"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -77,13 +317,13 @@ TEST(ManagedIdentityCredential, AppService)
 
   {
     EXPECT_NE(request0.Headers.find("secret"), request0.Headers.end());
-    EXPECT_EQ(request0.Headers.at("secret"), "CLIENTSECRET");
+    EXPECT_EQ(request0.Headers.at("secret"), "CLIENTSECRET1");
 
     EXPECT_NE(request1.Headers.find("secret"), request1.Headers.end());
-    EXPECT_EQ(request1.Headers.at("secret"), "CLIENTSECRET");
+    EXPECT_EQ(request1.Headers.at("secret"), "CLIENTSECRET1");
 
     EXPECT_NE(request2.Headers.find("secret"), request2.Headers.end());
-    EXPECT_EQ(request2.Headers.at("secret"), "CLIENTSECRET");
+    EXPECT_EQ(request2.Headers.at("secret"), "CLIENTSECRET1");
   }
 
   EXPECT_EQ(response0.AccessToken.Token, "ACCESSTOKEN1");
@@ -101,7 +341,7 @@ TEST(ManagedIdentityCredential, AppService)
   EXPECT_LE(response2.AccessToken.ExpiresOn, response2.LatestExpiration + 9999s);
 }
 
-TEST(ManagedIdentityCredential, AppServiceClientId)
+TEST(ManagedIdentityCredential, AppServiceV2017ClientId)
 {
   auto const actual = CredentialTestHelper::SimulateTokenRequest(
       [](auto transport) {
@@ -110,10 +350,10 @@ TEST(ManagedIdentityCredential, AppServiceClientId)
 
         CredentialTestHelper::EnvironmentOverride const env({
             {"MSI_ENDPOINT", "https://microsoft.com/"},
-            {"MSI_SECRET", "CLIENTSECRET"},
-            {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
+            {"IDENTITY_ENDPOINT", ""},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", "CLIENTSECRET2"},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -167,13 +407,13 @@ TEST(ManagedIdentityCredential, AppServiceClientId)
 
   {
     EXPECT_NE(request0.Headers.find("secret"), request0.Headers.end());
-    EXPECT_EQ(request0.Headers.at("secret"), "CLIENTSECRET");
+    EXPECT_EQ(request0.Headers.at("secret"), "CLIENTSECRET1");
 
     EXPECT_NE(request1.Headers.find("secret"), request1.Headers.end());
-    EXPECT_EQ(request1.Headers.at("secret"), "CLIENTSECRET");
+    EXPECT_EQ(request1.Headers.at("secret"), "CLIENTSECRET1");
 
     EXPECT_NE(request2.Headers.find("secret"), request2.Headers.end());
-    EXPECT_EQ(request2.Headers.at("secret"), "CLIENTSECRET");
+    EXPECT_EQ(request2.Headers.at("secret"), "CLIENTSECRET1");
   }
 
   EXPECT_EQ(response0.AccessToken.Token, "ACCESSTOKEN1");
@@ -191,7 +431,7 @@ TEST(ManagedIdentityCredential, AppServiceClientId)
   EXPECT_LE(response2.AccessToken.ExpiresOn, response2.LatestExpiration + 9999s);
 }
 
-TEST(ManagedIdentityCredential, AppServiceInvalidUrl)
+TEST(ManagedIdentityCredential, AppServiceV2017InvalidUrl)
 {
   using Azure::Core::Credentials::AccessToken;
   using Azure::Core::Credentials::AuthenticationException;
@@ -204,26 +444,26 @@ TEST(ManagedIdentityCredential, AppServiceInvalidUrl)
 
         CredentialTestHelper::EnvironmentOverride const env({
             {"MSI_ENDPOINT", "https://microsoft.com:INVALID/"},
-            {"MSI_SECRET", "CLIENTSECRET"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
-        std::unique_ptr<ManagedIdentityCredential const> appServiceManagedIdentityCredential;
+        std::unique_ptr<ManagedIdentityCredential const> appServiceV2017ManagedIdentityCredential;
         EXPECT_THROW(
-            appServiceManagedIdentityCredential
+            appServiceV2017ManagedIdentityCredential
             = std::make_unique<ManagedIdentityCredential>(options),
             AuthenticationException);
 
-        return appServiceManagedIdentityCredential;
+        return appServiceV2017ManagedIdentityCredential;
       },
       {},
       {"{\"expires_in\":3600, \"access_token\":\"ACCESSTOKEN1\"}"}));
 }
 
-TEST(ManagedIdentityCredential, AppServiceUnsupportedUrl)
+TEST(ManagedIdentityCredential, AppServiceV2017UnsupportedUrl)
 {
   using Azure::Core::Credentials::AccessToken;
   using Azure::Core::Credentials::AuthenticationException;
@@ -236,20 +476,20 @@ TEST(ManagedIdentityCredential, AppServiceUnsupportedUrl)
 
         CredentialTestHelper::EnvironmentOverride const env({
             {"MSI_ENDPOINT", "https://microsoft.com:65536/"},
-            {"MSI_SECRET", "CLIENTSECRET"},
-            {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
+            {"MSI_SECRET", "CLIENTSECRET1"},
+            {"IDENTITY_ENDPOINT", ""},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", "CLIENTSECRET2"},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
-        std::unique_ptr<ManagedIdentityCredential const> appServiceManagedIdentityCredential;
+        std::unique_ptr<ManagedIdentityCredential const> appServiceV2017ManagedIdentityCredential;
         EXPECT_THROW(
-            appServiceManagedIdentityCredential
+            appServiceV2017ManagedIdentityCredential
             = std::make_unique<ManagedIdentityCredential>(options),
             AuthenticationException);
 
-        return appServiceManagedIdentityCredential;
+        return appServiceV2017ManagedIdentityCredential;
       },
       {},
       {"{\"expires_in\":3600, \"access_token\":\"ACCESSTOKEN1\"}"}));
@@ -265,9 +505,9 @@ TEST(ManagedIdentityCredential, CloudShell)
         CredentialTestHelper::EnvironmentOverride const env({
             {"MSI_ENDPOINT", "https://microsoft.com/"},
             {"MSI_SECRET", ""},
-            {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
+            {"IDENTITY_ENDPOINT", ""},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", "SECRET2"},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -340,7 +580,7 @@ TEST(ManagedIdentityCredential, CloudShellClientId)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -423,7 +663,7 @@ TEST(ManagedIdentityCredential, CloudShellInvalidUrl)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -472,7 +712,7 @@ TEST(ManagedIdentityCredential, AzureArc)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -606,7 +846,7 @@ TEST(ManagedIdentityCredential, AzureArcClientId)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -637,7 +877,7 @@ TEST(ManagedIdentityCredential, AzureArcAuthHeaderMissing)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -676,7 +916,7 @@ TEST(ManagedIdentityCredential, AzureArcUnexpectedHttpStatusCode)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -710,7 +950,7 @@ TEST(ManagedIdentityCredential, AzureArcAuthHeaderNoEquals)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -742,7 +982,7 @@ TEST(ManagedIdentityCredential, AzureArcAuthHeaderTwoEquals)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });
 
@@ -774,7 +1014,7 @@ TEST(ManagedIdentityCredential, AzureArcInvalidUrl)
             {"MSI_SECRET", ""},
             {"IDENTITY_ENDPOINT", "https://visualstudio.com:INVALID/"},
             {"IMDS_ENDPOINT", "https://xbox.com/"},
-            {"IDENTITY_HEADER", "CLIENTSECRET"},
+            {"IDENTITY_HEADER", ""},
             {"IDENTITY_SERVER_THUMBPRINT", "0123456789abcdef0123456789abcdef01234567"},
         });