diff --git a/hack/test-cmd.sh b/hack/test-cmd.sh
index c396f8df00f..c276be950c6 100755
--- a/hack/test-cmd.sh
+++ b/hack/test-cmd.sh
@@ -178,7 +178,7 @@ kube::log::status "Starting kube-apiserver"
 # Admission Controllers to invoke prior to persisting objects in cluster
 ADMISSION_CONTROL="NamespaceLifecycle,LimitRanger,ResourceQuota"
 
-KUBE_API_VERSIONS="v1,extensions/v1beta1" "${KUBE_OUTPUT_HOSTBIN}/kube-apiserver" \
+KUBE_API_VERSIONS="v1,autoscaling/v1,extensions/v1beta1" "${KUBE_OUTPUT_HOSTBIN}/kube-apiserver" \
   --address="127.0.0.1" \
   --public-address-override="127.0.0.1" \
   --port="${API_PORT}" \
@@ -1548,7 +1548,7 @@ kube_api_versions=(
   v1
 )
 for version in "${kube_api_versions[@]}"; do
-  KUBE_API_VERSIONS="v1,extensions/v1beta1" runTests "${version}"
+  KUBE_API_VERSIONS="v1,autoscaling/v1,extensions/v1beta1" runTests "${version}"
 done
 
 kube::log::status "TEST PASSED"
diff --git a/hack/test-go.sh b/hack/test-go.sh
index 0d0148ba30c..7f55d71b6be 100755
--- a/hack/test-go.sh
+++ b/hack/test-go.sh
@@ -58,7 +58,7 @@ KUBE_GOVERALLS_BIN=${KUBE_GOVERALLS_BIN:-}
 # Lists of API Versions of each groups that should be tested, groups are
 # separated by comma, lists are separated by semicolon. e.g.,
 # "v1,compute/v1alpha1,experimental/v1alpha2;v1,compute/v2,experimental/v1alpha3"
-KUBE_TEST_API_VERSIONS=${KUBE_TEST_API_VERSIONS:-"v1,extensions/v1beta1,metrics/v1alpha1"}
+KUBE_TEST_API_VERSIONS=${KUBE_TEST_API_VERSIONS:-"v1,extensions/v1beta1,metrics/v1alpha1;v1,autoscaling/v1,extensions/v1beta1,metrics/v1alpha1"}
 # once we have multiple group supports
 # Run tests with the standard (registry) and a custom etcd prefix
 # (kubernetes.io/registry).
@@ -315,7 +315,7 @@ for (( i=0, j=0; ; )); do
   # KUBE_TEST_API sets the version of each group to be tested. KUBE_API_VERSIONS
   # register the groups/versions as supported by k8s. So KUBE_API_VERSIONS
   # needs to be the superset of KUBE_TEST_API.
-  KUBE_TEST_API="${apiVersion}" KUBE_API_VERSIONS="v1,extensions/v1beta1,componentconfig/v1alpha1,metrics/v1alpha1" ETCD_PREFIX=${etcdPrefix} runTests "$@"
+  KUBE_TEST_API="${apiVersion}" KUBE_API_VERSIONS="v1,autoscaling/v1,extensions/v1beta1,componentconfig/v1alpha1,metrics/v1alpha1" ETCD_PREFIX=${etcdPrefix} runTests "$@"
   i=${i}+1
   j=${j}+1
   if [[ i -eq ${apiVersionsCount} ]] && [[ j -eq ${etcdPrefixesCount} ]]; then
diff --git a/hack/test-integration.sh b/hack/test-integration.sh
index 10f5785f017..75266a344d9 100755
--- a/hack/test-integration.sh
+++ b/hack/test-integration.sh
@@ -29,7 +29,7 @@ source "${KUBE_ROOT}/hack/lib/init.sh"
 # "v1,compute/v1alpha1,experimental/v1alpha2;v1,compute/v2,experimental/v1alpha3"
 # TODO: It's going to be:
 # KUBE_TEST_API_VERSIONS=${KUBE_TEST_API_VERSIONS:-"v1,extensions/v1beta1"}
-KUBE_TEST_API_VERSIONS=${KUBE_TEST_API_VERSIONS:-"v1,extensions/v1beta1"}
+KUBE_TEST_API_VERSIONS=${KUBE_TEST_API_VERSIONS:-"v1,extensions/v1beta1;v1,autoscaling/v1,extensions/v1beta1"}
 
 # Give integration tests longer to run
 KUBE_TIMEOUT=${KUBE_TIMEOUT:--timeout 240s}
@@ -52,22 +52,21 @@ runTests() {
     KUBE_RACE="" \
     KUBE_TIMEOUT="${KUBE_TIMEOUT}" \
     KUBE_TEST_API_VERSIONS="$1" \
-    KUBE_API_VERSIONS="v1,extensions/v1beta1" \
+    KUBE_API_VERSIONS="v1,autoscaling/v1,extensions/v1beta1" \
     "${KUBE_ROOT}/hack/test-go.sh" test/integration
 
   kube::log::status "Running integration test scenario with watch cache on"
-  KUBE_API_VERSIONS="v1,extensions/v1beta1" KUBE_TEST_API_VERSIONS="$1" "${KUBE_OUTPUT_HOSTBIN}/integration" --v=${LOG_LEVEL} \
+  KUBE_API_VERSIONS="v1,autoscaling/v1,extensions/v1beta1" KUBE_TEST_API_VERSIONS="$1" "${KUBE_OUTPUT_HOSTBIN}/integration" --v=${LOG_LEVEL} \
     --max-concurrency="${KUBE_INTEGRATION_TEST_MAX_CONCURRENCY}" --watch-cache=true
 
   kube::log::status "Running integration test scenario with watch cache off"
-  KUBE_API_VERSIONS="v1,extensions/v1beta1" KUBE_TEST_API_VERSIONS="$1" "${KUBE_OUTPUT_HOSTBIN}/integration" --v=${LOG_LEVEL} \
+  KUBE_API_VERSIONS="v1,autoscaling/v1,extensions/v1beta1" KUBE_TEST_API_VERSIONS="$1" "${KUBE_OUTPUT_HOSTBIN}/integration" --v=${LOG_LEVEL} \
     --max-concurrency="${KUBE_INTEGRATION_TEST_MAX_CONCURRENCY}" --watch-cache=false
 
-
   cleanup
 }
 
-KUBE_API_VERSIONS="v1,extensions/v1beta1" "${KUBE_ROOT}/hack/build-go.sh" "$@" cmd/integration
+KUBE_API_VERSIONS="v1,autoscaling/v1,extensions/v1beta1" "${KUBE_ROOT}/hack/build-go.sh" "$@" cmd/integration
 
 # Run cleanup to stop etcd on interrupt or other kill signal.
 trap cleanup EXIT
diff --git a/pkg/api/testapi/testapi.go b/pkg/api/testapi/testapi.go
index d3fc91aae27..9170052e3b6 100644
--- a/pkg/api/testapi/testapi.go
+++ b/pkg/api/testapi/testapi.go
@@ -26,19 +26,22 @@ import (
 	"k8s.io/kubernetes/pkg/api/meta"
 	"k8s.io/kubernetes/pkg/api/unversioned"
 	"k8s.io/kubernetes/pkg/apimachinery/registered"
+	"k8s.io/kubernetes/pkg/apis/autoscaling"
 	"k8s.io/kubernetes/pkg/apis/extensions"
 	"k8s.io/kubernetes/pkg/runtime"
 
 	_ "k8s.io/kubernetes/pkg/api/install"
+	_ "k8s.io/kubernetes/pkg/apis/autoscaling/install"
 	_ "k8s.io/kubernetes/pkg/apis/componentconfig/install"
 	_ "k8s.io/kubernetes/pkg/apis/extensions/install"
 	_ "k8s.io/kubernetes/pkg/apis/metrics/install"
 )
 
 var (
-	Groups     = make(map[string]TestGroup)
-	Default    TestGroup
-	Extensions TestGroup
+	Groups      = make(map[string]TestGroup)
+	Default     TestGroup
+	Autoscaling TestGroup
+	Extensions  TestGroup
 )
 
 type TestGroup struct {
@@ -69,6 +72,12 @@ func init() {
 			internalGroupVersion: api.SchemeGroupVersion,
 		}
 	}
+	if _, ok := Groups[autoscaling.GroupName]; !ok {
+		Groups[autoscaling.GroupName] = TestGroup{
+			externalGroupVersion: unversioned.GroupVersion{Group: autoscaling.GroupName, Version: registered.GroupOrDie(autoscaling.GroupName).GroupVersion.Version},
+			internalGroupVersion: autoscaling.SchemeGroupVersion,
+		}
+	}
 	if _, ok := Groups[extensions.GroupName]; !ok {
 		Groups[extensions.GroupName] = TestGroup{
 			externalGroupVersion: unversioned.GroupVersion{Group: extensions.GroupName, Version: registered.GroupOrDie(extensions.GroupName).GroupVersion.Version},
@@ -77,6 +86,7 @@ func init() {
 	}
 
 	Default = Groups[api.GroupName]
+	Autoscaling = Groups[autoscaling.GroupName]
 	Extensions = Groups[extensions.GroupName]
 }
 
diff --git a/pkg/api/testapi/testapi_test.go b/pkg/api/testapi/testapi_test.go
index 7b8bb02ba36..7d9ad0ec0d9 100644
--- a/pkg/api/testapi/testapi_test.go
+++ b/pkg/api/testapi/testapi_test.go
@@ -100,9 +100,8 @@ func TestV1EncodeDecodeStatus(t *testing.T) {
 	}
 }
 
-func TestExperimentalEncodeDecodeStatus(t *testing.T) {
-	extensionCodec := Extensions.Codec()
-	encoded, err := runtime.Encode(extensionCodec, status)
+func testEncodeDecodeStatus(t *testing.T, codec runtime.Codec) {
+	encoded, err := runtime.Encode(codec, status)
 	if err != nil {
 		t.Errorf("unexpected error: %v", err)
 	}
@@ -116,7 +115,7 @@ func TestExperimentalEncodeDecodeStatus(t *testing.T) {
 	if typeMeta.APIVersion != "v1" {
 		t.Errorf("APIVersion is not set to \"\". Got %s", encoded)
 	}
-	decoded, err := runtime.Decode(extensionCodec, encoded)
+	decoded, err := runtime.Decode(codec, encoded)
 	if err != nil {
 		t.Errorf("unexpected error: %v", err)
 	}
@@ -124,3 +123,11 @@ func TestExperimentalEncodeDecodeStatus(t *testing.T) {
 		t.Errorf("expected: %v, got: %v", status, decoded)
 	}
 }
+
+func TestAutoscalingEncodeDecodeStatus(t *testing.T) {
+	testEncodeDecodeStatus(t, Autoscaling.Codec())
+}
+
+func TestExperimentalEncodeDecodeStatus(t *testing.T) {
+	testEncodeDecodeStatus(t, Extensions.Codec())
+}
diff --git a/pkg/api/testing/fuzzer.go b/pkg/api/testing/fuzzer.go
index 4375d26619d..092802d111f 100644
--- a/pkg/api/testing/fuzzer.go
+++ b/pkg/api/testing/fuzzer.go
@@ -397,6 +397,10 @@ func FuzzerFor(t *testing.T, version unversioned.GroupVersion, src rand.Source)
 			s.MinReplicas = &minReplicas
 			s.CPUUtilization = &extensions.CPUTargetUtilization{TargetPercentage: int(int32(c.RandUint64()))}
 		},
+		func(s *extensions.SubresourceReference, c fuzz.Continue) {
+			c.FuzzNoCustom(s) // fuzz self without calling this function again
+			s.Subresource = "scale"
+		},
 		func(psp *extensions.PodSecurityPolicySpec, c fuzz.Continue) {
 			c.FuzzNoCustom(psp) // fuzz self without calling this function again
 			userTypes := []extensions.RunAsUserStrategy{extensions.RunAsUserStrategyMustRunAsNonRoot, extensions.RunAsUserStrategyMustRunAs, extensions.RunAsUserStrategyRunAsAny}
diff --git a/pkg/client/unversioned/horizontalpodautoscaler_test.go b/pkg/client/unversioned/horizontalpodautoscaler_test.go
index bd4c06c8259..b35d258af3e 100644
--- a/pkg/client/unversioned/horizontalpodautoscaler_test.go
+++ b/pkg/client/unversioned/horizontalpodautoscaler_test.go
@@ -27,6 +27,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/testapi"
+	"k8s.io/kubernetes/pkg/apis/autoscaling"
 	"k8s.io/kubernetes/pkg/apis/extensions"
 )
 
@@ -34,7 +35,19 @@ func getHorizontalPodAutoscalersResoureName() string {
 	return "horizontalpodautoscalers"
 }
 
-func TestHorizontalPodAutoscalerCreate(t *testing.T) {
+func getClient(t *testing.T, c *simple.Client, ns, resourceGroup string) HorizontalPodAutoscalerInterface {
+	switch resourceGroup {
+	case autoscaling.GroupName:
+		return c.Setup(t).Autoscaling().HorizontalPodAutoscalers(ns)
+	case extensions.GroupName:
+		return c.Setup(t).Extensions().HorizontalPodAutoscalers(ns)
+	default:
+		t.Fatalf("Unknown group %v", resourceGroup)
+	}
+	return nil
+}
+
+func testHorizontalPodAutoscalerCreate(t *testing.T, group testapi.TestGroup, resourceGroup string) {
 	ns := api.NamespaceDefault
 	horizontalPodAutoscaler := extensions.HorizontalPodAutoscaler{
 		ObjectMeta: api.ObjectMeta{
@@ -45,14 +58,15 @@ func TestHorizontalPodAutoscalerCreate(t *testing.T) {
 	c := &simple.Client{
 		Request: simple.Request{
 			Method: "POST",
-			Path:   testapi.Extensions.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, ""),
+			Path:   group.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, ""),
 			Query:  simple.BuildQueryValues(nil),
 			Body:   &horizontalPodAutoscaler,
 		},
-		Response: simple.Response{StatusCode: 200, Body: &horizontalPodAutoscaler},
+		Response:      simple.Response{StatusCode: 200, Body: &horizontalPodAutoscaler},
+		ResourceGroup: resourceGroup,
 	}
 
-	response, err := c.Setup(t).Extensions().HorizontalPodAutoscalers(ns).Create(&horizontalPodAutoscaler)
+	response, err := getClient(t, c, ns, resourceGroup).Create(&horizontalPodAutoscaler)
 	defer c.Close()
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
@@ -60,7 +74,12 @@ func TestHorizontalPodAutoscalerCreate(t *testing.T) {
 	c.Validate(t, response, err)
 }
 
-func TestHorizontalPodAutoscalerGet(t *testing.T) {
+func TestHorizontalPodAutoscalerCreate(t *testing.T) {
+	testHorizontalPodAutoscalerCreate(t, testapi.Extensions, extensions.GroupName)
+	testHorizontalPodAutoscalerCreate(t, testapi.Autoscaling, autoscaling.GroupName)
+}
+
+func testHorizontalPodAutoscalerGet(t *testing.T, group testapi.TestGroup, resourceGroup string) {
 	ns := api.NamespaceDefault
 	horizontalPodAutoscaler := &extensions.HorizontalPodAutoscaler{
 		ObjectMeta: api.ObjectMeta{
@@ -71,19 +90,25 @@ func TestHorizontalPodAutoscalerGet(t *testing.T) {
 	c := &simple.Client{
 		Request: simple.Request{
 			Method: "GET",
-			Path:   testapi.Extensions.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "abc"),
+			Path:   group.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "abc"),
 			Query:  simple.BuildQueryValues(nil),
 			Body:   nil,
 		},
-		Response: simple.Response{StatusCode: 200, Body: horizontalPodAutoscaler},
+		Response:      simple.Response{StatusCode: 200, Body: horizontalPodAutoscaler},
+		ResourceGroup: resourceGroup,
 	}
 
-	response, err := c.Setup(t).Extensions().HorizontalPodAutoscalers(ns).Get("abc")
+	response, err := getClient(t, c, ns, resourceGroup).Get("abc")
 	defer c.Close()
 	c.Validate(t, response, err)
 }
 
-func TestHorizontalPodAutoscalerList(t *testing.T) {
+func TestHorizontalPodAutoscalerGet(t *testing.T) {
+	testHorizontalPodAutoscalerGet(t, testapi.Extensions, extensions.GroupName)
+	testHorizontalPodAutoscalerGet(t, testapi.Autoscaling, autoscaling.GroupName)
+}
+
+func testHorizontalPodAutoscalerList(t *testing.T, group testapi.TestGroup, resourceGroup string) {
 	ns := api.NamespaceDefault
 	horizontalPodAutoscalerList := &extensions.HorizontalPodAutoscalerList{
 		Items: []extensions.HorizontalPodAutoscaler{
@@ -98,18 +123,48 @@ func TestHorizontalPodAutoscalerList(t *testing.T) {
 	c := &simple.Client{
 		Request: simple.Request{
 			Method: "GET",
-			Path:   testapi.Extensions.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, ""),
+			Path:   group.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, ""),
 			Query:  simple.BuildQueryValues(nil),
 			Body:   nil,
 		},
-		Response: simple.Response{StatusCode: 200, Body: horizontalPodAutoscalerList},
+		Response:      simple.Response{StatusCode: 200, Body: horizontalPodAutoscalerList},
+		ResourceGroup: resourceGroup,
 	}
-	response, err := c.Setup(t).Extensions().HorizontalPodAutoscalers(ns).List(api.ListOptions{})
+	response, err := getClient(t, c, ns, resourceGroup).List(api.ListOptions{})
+	defer c.Close()
+	c.Validate(t, response, err)
+}
+
+func TestHorizontalPodAutoscalerList(t *testing.T) {
+	testHorizontalPodAutoscalerList(t, testapi.Extensions, extensions.GroupName)
+	testHorizontalPodAutoscalerList(t, testapi.Autoscaling, autoscaling.GroupName)
+}
+
+func testHorizontalPodAutoscalerUpdate(t *testing.T, group testapi.TestGroup, resourceGroup string) {
+	ns := api.NamespaceDefault
+	horizontalPodAutoscaler := &extensions.HorizontalPodAutoscaler{
+		ObjectMeta: api.ObjectMeta{
+			Name:            "abc",
+			Namespace:       ns,
+			ResourceVersion: "1",
+		},
+	}
+	c := &simple.Client{
+		Request:       simple.Request{Method: "PUT", Path: group.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "abc"), Query: simple.BuildQueryValues(nil)},
+		Response:      simple.Response{StatusCode: 200, Body: horizontalPodAutoscaler},
+		ResourceGroup: resourceGroup,
+	}
+	response, err := getClient(t, c, ns, resourceGroup).Update(horizontalPodAutoscaler)
 	defer c.Close()
 	c.Validate(t, response, err)
 }
 
 func TestHorizontalPodAutoscalerUpdate(t *testing.T) {
+	testHorizontalPodAutoscalerUpdate(t, testapi.Extensions, extensions.GroupName)
+	testHorizontalPodAutoscalerUpdate(t, testapi.Autoscaling, autoscaling.GroupName)
+}
+
+func testHorizontalPodAutoscalerUpdateStatus(t *testing.T, group testapi.TestGroup, resourceGroup string) {
 	ns := api.NamespaceDefault
 	horizontalPodAutoscaler := &extensions.HorizontalPodAutoscaler{
 		ObjectMeta: api.ObjectMeta{
@@ -119,52 +174,52 @@ func TestHorizontalPodAutoscalerUpdate(t *testing.T) {
 		},
 	}
 	c := &simple.Client{
-		Request:  simple.Request{Method: "PUT", Path: testapi.Extensions.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "abc"), Query: simple.BuildQueryValues(nil)},
-		Response: simple.Response{StatusCode: 200, Body: horizontalPodAutoscaler},
+		Request:       simple.Request{Method: "PUT", Path: group.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "abc") + "/status", Query: simple.BuildQueryValues(nil)},
+		Response:      simple.Response{StatusCode: 200, Body: horizontalPodAutoscaler},
+		ResourceGroup: resourceGroup,
 	}
-	response, err := c.Setup(t).Extensions().HorizontalPodAutoscalers(ns).Update(horizontalPodAutoscaler)
+	response, err := getClient(t, c, ns, resourceGroup).UpdateStatus(horizontalPodAutoscaler)
 	defer c.Close()
 	c.Validate(t, response, err)
 }
 
 func TestHorizontalPodAutoscalerUpdateStatus(t *testing.T) {
+	testHorizontalPodAutoscalerUpdateStatus(t, testapi.Extensions, extensions.GroupName)
+	testHorizontalPodAutoscalerUpdateStatus(t, testapi.Autoscaling, autoscaling.GroupName)
+}
+
+func testHorizontalPodAutoscalerDelete(t *testing.T, group testapi.TestGroup, resourceGroup string) {
 	ns := api.NamespaceDefault
-	horizontalPodAutoscaler := &extensions.HorizontalPodAutoscaler{
-		ObjectMeta: api.ObjectMeta{
-			Name:            "abc",
-			Namespace:       ns,
-			ResourceVersion: "1",
-		},
-	}
 	c := &simple.Client{
-		Request:  simple.Request{Method: "PUT", Path: testapi.Extensions.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "abc") + "/status", Query: simple.BuildQueryValues(nil)},
-		Response: simple.Response{StatusCode: 200, Body: horizontalPodAutoscaler},
+		Request:       simple.Request{Method: "DELETE", Path: group.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "foo"), Query: simple.BuildQueryValues(nil)},
+		Response:      simple.Response{StatusCode: 200},
+		ResourceGroup: resourceGroup,
 	}
-	response, err := c.Setup(t).Extensions().HorizontalPodAutoscalers(ns).UpdateStatus(horizontalPodAutoscaler)
+	err := getClient(t, c, ns, resourceGroup).Delete("foo", nil)
 	defer c.Close()
-	c.Validate(t, response, err)
+	c.Validate(t, nil, err)
 }
 
 func TestHorizontalPodAutoscalerDelete(t *testing.T) {
-	ns := api.NamespaceDefault
+	testHorizontalPodAutoscalerDelete(t, testapi.Extensions, extensions.GroupName)
+	testHorizontalPodAutoscalerDelete(t, testapi.Autoscaling, autoscaling.GroupName)
+}
+
+func testHorizontalPodAutoscalerWatch(t *testing.T, group testapi.TestGroup, resourceGroup string) {
 	c := &simple.Client{
-		Request:  simple.Request{Method: "DELETE", Path: testapi.Extensions.ResourcePath(getHorizontalPodAutoscalersResoureName(), ns, "foo"), Query: simple.BuildQueryValues(nil)},
-		Response: simple.Response{StatusCode: 200},
+		Request: simple.Request{
+			Method: "GET",
+			Path:   group.ResourcePathWithPrefix("watch", getHorizontalPodAutoscalersResoureName(), "", ""),
+			Query:  url.Values{"resourceVersion": []string{}}},
+		Response:      simple.Response{StatusCode: 200},
+		ResourceGroup: resourceGroup,
 	}
-	err := c.Setup(t).Extensions().HorizontalPodAutoscalers(ns).Delete("foo", nil)
+	_, err := getClient(t, c, api.NamespaceAll, resourceGroup).Watch(api.ListOptions{})
 	defer c.Close()
 	c.Validate(t, nil, err)
 }
 
 func TestHorizontalPodAutoscalerWatch(t *testing.T) {
-	c := &simple.Client{
-		Request: simple.Request{
-			Method: "GET",
-			Path:   testapi.Extensions.ResourcePathWithPrefix("watch", getHorizontalPodAutoscalersResoureName(), "", ""),
-			Query:  url.Values{"resourceVersion": []string{}}},
-		Response: simple.Response{StatusCode: 200},
-	}
-	_, err := c.Setup(t).Extensions().HorizontalPodAutoscalers(api.NamespaceAll).Watch(api.ListOptions{})
-	defer c.Close()
-	c.Validate(t, nil, err)
+	testHorizontalPodAutoscalerWatch(t, testapi.Extensions, extensions.GroupName)
+	testHorizontalPodAutoscalerWatch(t, testapi.Autoscaling, autoscaling.GroupName)
 }
diff --git a/pkg/client/unversioned/testclient/simple/simple_testclient.go b/pkg/client/unversioned/testclient/simple/simple_testclient.go
index 08b979501d2..ab32f5295ee 100644
--- a/pkg/client/unversioned/testclient/simple/simple_testclient.go
+++ b/pkg/client/unversioned/testclient/simple/simple_testclient.go
@@ -66,13 +66,17 @@ type Client struct {
 	// Maps from query arg key to validator.
 	// If no validator is present, string equality is used.
 	QueryValidator map[string]func(string, string) bool
+
+	// If your object could exist in multiple groups, set this to
+	// correspond to the URL you're testing it with.
+	ResourceGroup string
 }
 
 func (c *Client) Setup(t *testing.T) *Client {
 	c.handler = &utiltesting.FakeHandler{
 		StatusCode: c.Response.StatusCode,
 	}
-	if responseBody := body(t, c.Response.Body, c.Response.RawBody); responseBody != nil {
+	if responseBody := c.body(t, c.Response.Body, c.Response.RawBody); responseBody != nil {
 		c.handler.ResponseBody = *responseBody
 	}
 	c.server = httptest.NewServer(c.handler)
@@ -142,7 +146,7 @@ func (c *Client) ValidateCommon(t *testing.T, err error) {
 		return
 	}
 
-	requestBody := body(t, c.Request.Body, c.Request.RawBody)
+	requestBody := c.body(t, c.Request.Body, c.Request.RawBody)
 	actualQuery := c.handler.RequestReceived.URL.Query()
 	t.Logf("got query: %v", actualQuery)
 	t.Logf("path: %v", c.Request.Path)
@@ -210,16 +214,20 @@ func validateFields(a, b string) bool {
 	return sA.String() == sB.String()
 }
 
-func body(t *testing.T, obj runtime.Object, raw *string) *string {
+func (c *Client) body(t *testing.T, obj runtime.Object, raw *string) *string {
 	if obj != nil {
 		fqKind, err := api.Scheme.ObjectKind(obj)
 		if err != nil {
 			t.Errorf("unexpected encoding error: %v", err)
 		}
+		groupName := fqKind.GroupVersion().Group
+		if c.ResourceGroup != "" {
+			groupName = c.ResourceGroup
+		}
 		var bs []byte
-		g, found := testapi.Groups[fqKind.GroupVersion().Group]
+		g, found := testapi.Groups[groupName]
 		if !found {
-			t.Errorf("Group %s is not registered in testapi", fqKind.GroupVersion().Group)
+			t.Errorf("Group %s is not registered in testapi", groupName)
 		}
 		bs, err = runtime.Encode(g.Codec(), obj)
 		if err != nil {
diff --git a/pkg/master/master_test.go b/pkg/master/master_test.go
index 30e18b5f775..03f44567e99 100644
--- a/pkg/master/master_test.go
+++ b/pkg/master/master_test.go
@@ -35,6 +35,7 @@ import (
 	apiutil "k8s.io/kubernetes/pkg/api/util"
 	utilnet "k8s.io/kubernetes/pkg/util/net"
 
+	"k8s.io/kubernetes/pkg/apis/autoscaling"
 	"k8s.io/kubernetes/pkg/apis/extensions"
 	"k8s.io/kubernetes/pkg/genericapiserver"
 	"k8s.io/kubernetes/pkg/kubelet/client"
@@ -66,11 +67,14 @@ func setUp(t *testing.T) (Master, *etcdtesting.EtcdTestServer, Config, *assert.A
 	storageDestinations := genericapiserver.NewStorageDestinations()
 	storageDestinations.AddAPIGroup(
 		api.GroupName, etcdstorage.NewEtcdStorage(server.Client, testapi.Default.Codec(), etcdtest.PathPrefix(), false))
+	storageDestinations.AddAPIGroup(
+		autoscaling.GroupName, etcdstorage.NewEtcdStorage(server.Client, testapi.Autoscaling.Codec(), etcdtest.PathPrefix(), false))
 	storageDestinations.AddAPIGroup(
 		extensions.GroupName, etcdstorage.NewEtcdStorage(server.Client, testapi.Extensions.Codec(), etcdtest.PathPrefix(), false))
 
 	config.StorageDestinations = storageDestinations
 	storageVersions[api.GroupName] = testapi.Default.GroupVersion().String()
+	storageVersions[autoscaling.GroupName] = testapi.Autoscaling.GroupVersion().String()
 	storageVersions[extensions.GroupName] = testapi.Extensions.GroupVersion().String()
 	config.StorageVersions = storageVersions
 	config.PublicAddress = net.ParseIP("192.168.10.4")
@@ -274,20 +278,40 @@ func TestDiscoveryAtAPIS(t *testing.T) {
 		t.Fatalf("unexpected error: %v", err)
 	}
 
-	extensionsGroupName := extensions.GroupName
-	extensionsVersions := []unversioned.GroupVersionForDiscovery{
+	expectGroupNames := []string{autoscaling.GroupName, extensions.GroupName}
+	expectVersions := [][]unversioned.GroupVersionForDiscovery{
 		{
-			GroupVersion: testapi.Extensions.GroupVersion().String(),
-			Version:      testapi.Extensions.GroupVersion().Version,
+			{
+				GroupVersion: testapi.Autoscaling.GroupVersion().String(),
+				Version:      testapi.Autoscaling.GroupVersion().Version,
+			},
+		},
+		{
+			{
+				GroupVersion: testapi.Extensions.GroupVersion().String(),
+				Version:      testapi.Extensions.GroupVersion().Version,
+			},
 		},
 	}
-	extensionsPreferredVersion := unversioned.GroupVersionForDiscovery{
-		GroupVersion: config.StorageVersions[extensions.GroupName],
-		Version:      apiutil.GetVersion(config.StorageVersions[extensions.GroupName]),
+	expectPreferredVersion := []unversioned.GroupVersionForDiscovery{
+		{
+			GroupVersion: config.StorageVersions[autoscaling.GroupName],
+			Version:      apiutil.GetVersion(config.StorageVersions[autoscaling.GroupName]),
+		},
+		{
+			GroupVersion: config.StorageVersions[extensions.GroupName],
+			Version:      apiutil.GetVersion(config.StorageVersions[extensions.GroupName]),
+		},
 	}
-	assert.Equal(extensionsGroupName, groupList.Groups[0].Name)
-	assert.Equal(extensionsVersions, groupList.Groups[0].Versions)
-	assert.Equal(extensionsPreferredVersion, groupList.Groups[0].PreferredVersion)
+
+	assert.Equal(expectGroupNames[0], groupList.Groups[0].Name)
+	assert.Equal(expectGroupNames[1], groupList.Groups[1].Name)
+
+	assert.Equal(expectVersions[0], groupList.Groups[0].Versions)
+	assert.Equal(expectVersions[1], groupList.Groups[1].Versions)
+
+	assert.Equal(expectPreferredVersion[0], groupList.Groups[0].PreferredVersion)
+	assert.Equal(expectPreferredVersion[1], groupList.Groups[1].PreferredVersion)
 
 	thirdPartyGV := unversioned.GroupVersionForDiscovery{GroupVersion: "company.com/v1", Version: "v1"}
 	master.addThirdPartyResourceStorage("/apis/company.com/v1", nil,
@@ -312,13 +336,19 @@ func TestDiscoveryAtAPIS(t *testing.T) {
 	thirdPartyGroupName := "company.com"
 	thirdPartyExpectVersions := []unversioned.GroupVersionForDiscovery{thirdPartyGV}
 
-	assert.Equal(2, len(groupList.Groups))
-	assert.Equal(thirdPartyGroupName, groupList.Groups[0].Name)
-	assert.Equal(thirdPartyExpectVersions, groupList.Groups[0].Versions)
-	assert.Equal(thirdPartyGV, groupList.Groups[0].PreferredVersion)
-	assert.Equal(extensionsGroupName, groupList.Groups[1].Name)
-	assert.Equal(extensionsVersions, groupList.Groups[1].Versions)
-	assert.Equal(extensionsPreferredVersion, groupList.Groups[1].PreferredVersion)
+	assert.Equal(3, len(groupList.Groups))
+	// autoscaling group
+	assert.Equal(expectGroupNames[0], groupList.Groups[0].Name)
+	assert.Equal(expectVersions[0], groupList.Groups[0].Versions)
+	assert.Equal(expectPreferredVersion[0], groupList.Groups[0].PreferredVersion)
+	// third party
+	assert.Equal(thirdPartyGroupName, groupList.Groups[1].Name)
+	assert.Equal(thirdPartyExpectVersions, groupList.Groups[1].Versions)
+	assert.Equal(thirdPartyGV, groupList.Groups[1].PreferredVersion)
+	// extensions group
+	assert.Equal(expectGroupNames[1], groupList.Groups[2].Name)
+	assert.Equal(expectVersions[1], groupList.Groups[2].Versions)
+	assert.Equal(expectPreferredVersion[1], groupList.Groups[2].PreferredVersion)
 }
 
 var versionsToTest = []string{"v1", "v3"}
diff --git a/test/integration/auth_test.go b/test/integration/auth_test.go
index ba7e1525838..32b1cf793f7 100644
--- a/test/integration/auth_test.go
+++ b/test/integration/auth_test.go
@@ -38,6 +38,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/testapi"
+	"k8s.io/kubernetes/pkg/apis/autoscaling"
 	"k8s.io/kubernetes/pkg/apis/extensions"
 	"k8s.io/kubernetes/pkg/apiserver"
 	"k8s.io/kubernetes/pkg/auth/authenticator"
@@ -780,8 +781,9 @@ func TestAuthorizationAttributeDetermination(t *testing.T) {
 		URL                string
 		expectedAttributes authorizer.Attributes
 	}{
-		"prefix/version/resource":       {"GET", "/api/v1/pods", authorizer.AttributesRecord{APIGroup: api.GroupName, Resource: "pods"}},
-		"prefix/group/version/resource": {"GET", "/apis/extensions/v1/pods", authorizer.AttributesRecord{APIGroup: extensions.GroupName, Resource: "pods"}},
+		"prefix/version/resource":        {"GET", "/api/v1/pods", authorizer.AttributesRecord{APIGroup: api.GroupName, Resource: "pods"}},
+		"prefix/group/version/resource":  {"GET", "/apis/extensions/v1/pods", authorizer.AttributesRecord{APIGroup: extensions.GroupName, Resource: "pods"}},
+		"prefix/group/version/resource2": {"GET", "/apis/autoscaling/v1/horizontalpodautoscalers", authorizer.AttributesRecord{APIGroup: autoscaling.GroupName, Resource: "horizontalpodautoscalers"}},
 	}
 
 	currentAuthorizationAttributesIndex := 0
diff --git a/test/integration/framework/etcd_utils.go b/test/integration/framework/etcd_utils.go
index d02b97d8082..8270e423268 100644
--- a/test/integration/framework/etcd_utils.go
+++ b/test/integration/framework/etcd_utils.go
@@ -52,6 +52,13 @@ func NewEtcdStorage() storage.Interface {
 	return etcdstorage.NewEtcdStorage(NewEtcdClient(), testapi.Default.Codec(), etcdtest.PathPrefix(), false)
 }
 
+func NewAutoscalingEtcdStorage(client etcd.Client) storage.Interface {
+	if client == nil {
+		client = NewEtcdClient()
+	}
+	return etcdstorage.NewEtcdStorage(client, testapi.Autoscaling.Codec(), etcdtest.PathPrefix(), false)
+}
+
 func NewExtensionsEtcdStorage(client etcd.Client) storage.Interface {
 	if client == nil {
 		client = NewEtcdClient()
diff --git a/test/integration/framework/master_utils.go b/test/integration/framework/master_utils.go
index eb945bdf79c..2fb7a6e80f2 100644
--- a/test/integration/framework/master_utils.go
+++ b/test/integration/framework/master_utils.go
@@ -29,6 +29,7 @@ import (
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/testapi"
+	"k8s.io/kubernetes/pkg/apis/autoscaling"
 	"k8s.io/kubernetes/pkg/apis/extensions"
 	"k8s.io/kubernetes/pkg/apiserver"
 	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
@@ -150,11 +151,14 @@ func NewMasterConfig() *master.Config {
 
 	etcdStorage := etcdstorage.NewEtcdStorage(etcdClient, testapi.Default.Codec(), etcdtest.PathPrefix(), false)
 	storageVersions[api.GroupName] = testapi.Default.GroupVersion().String()
+	autoscalingEtcdStorage := NewAutoscalingEtcdStorage(etcdClient)
+	storageVersions[autoscaling.GroupName] = testapi.Autoscaling.GroupVersion().String()
 	expEtcdStorage := NewExtensionsEtcdStorage(etcdClient)
 	storageVersions[extensions.GroupName] = testapi.Extensions.GroupVersion().String()
 
 	storageDestinations := genericapiserver.NewStorageDestinations()
 	storageDestinations.AddAPIGroup(api.GroupName, etcdStorage)
+	storageDestinations.AddAPIGroup(autoscaling.GroupName, autoscalingEtcdStorage)
 	storageDestinations.AddAPIGroup(extensions.GroupName, expEtcdStorage)
 
 	return &master.Config{
diff --git a/test/integration/master_test.go b/test/integration/master_test.go
index 91d9685e69c..15b6a43fde8 100644
--- a/test/integration/master_test.go
+++ b/test/integration/master_test.go
@@ -19,30 +19,42 @@ limitations under the License.
 package integration
 
 import (
+	"bytes"
 	"encoding/json"
 	"io/ioutil"
 	"net/http"
+	"strings"
 	"testing"
 
 	"github.com/ghodss/yaml"
 
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/testapi"
 	"k8s.io/kubernetes/test/integration/framework"
 )
 
-func TestExperimentalPrefix(t *testing.T) {
+func testPrefix(t *testing.T, prefix string) {
 	_, s := framework.RunAMaster(t)
 	// TODO: Uncomment when fix #19254
 	// defer s.Close()
 
-	resp, err := http.Get(s.URL + "/apis/extensions/")
+	resp, err := http.Get(s.URL + prefix)
 	if err != nil {
-		t.Fatalf("unexpected error getting experimental prefix: %v", err)
+		t.Fatalf("unexpected error getting %s prefix: %v", prefix, err)
 	}
 	if resp.StatusCode != http.StatusOK {
 		t.Fatalf("got status %v instead of 200 OK", resp.StatusCode)
 	}
 }
 
+func TestAutoscalingPrefix(t *testing.T) {
+	testPrefix(t, "/apis/autoscaling/")
+}
+
+func TestExtensionsPrefix(t *testing.T) {
+	testPrefix(t, "/apis/extensions/")
+}
+
 func TestWatchSucceedsWithoutArgs(t *testing.T) {
 	_, s := framework.RunAMaster(t)
 	// TODO: Uncomment when fix #19254
@@ -58,6 +70,81 @@ func TestWatchSucceedsWithoutArgs(t *testing.T) {
 	resp.Body.Close()
 }
 
+var hpaV1 string = `
+{
+  "apiVersion": "autoscaling/v1",
+  "kind": "HorizontalPodAutoscaler",
+  "metadata": {
+    "name": "test-hpa",
+    "namespace": "default"
+  },
+  "spec": {
+    "scaleTargetRef": {
+      "kind": "ReplicationController",
+      "name": "test-hpa",
+      "namespace": "default"
+    },
+    "minReplicas": 1,
+    "maxReplicas": 10,
+    "targetCPUUtilizationPercentage": 50
+  }
+}
+`
+
+func autoscalingPath(resource, namespace, name string) string {
+	return testapi.Autoscaling.ResourcePath(resource, namespace, name)
+}
+
+func extensionsPath(resource, namespace, name string) string {
+	return testapi.Extensions.ResourcePath(resource, namespace, name)
+}
+
+func TestAutoscalingGroupBackwardCompatibility(t *testing.T) {
+	_, s := framework.RunAMaster(t)
+	defer s.Close()
+	transport := http.DefaultTransport
+
+	requests := []struct {
+		verb                string
+		URL                 string
+		body                string
+		expectedStatusCodes map[int]bool
+		expectedVersion     string
+	}{
+		{"POST", autoscalingPath("horizontalpodautoscalers", api.NamespaceDefault, ""), hpaV1, code201, ""},
+		{"GET", autoscalingPath("horizontalpodautoscalers", api.NamespaceDefault, ""), "", code200, testapi.Autoscaling.GroupVersion().String()},
+		{"GET", extensionsPath("horizontalpodautoscalers", api.NamespaceDefault, ""), "", code200, testapi.Extensions.GroupVersion().String()},
+	}
+
+	for _, r := range requests {
+		bodyBytes := bytes.NewReader([]byte(r.body))
+		req, err := http.NewRequest(r.verb, s.URL+r.URL, bodyBytes)
+		if err != nil {
+			t.Logf("case %v", r)
+			t.Fatalf("unexpected error: %v", err)
+		}
+		func() {
+			resp, err := transport.RoundTrip(req)
+			defer resp.Body.Close()
+			if err != nil {
+				t.Logf("case %v", r)
+				t.Fatalf("unexpected error: %v", err)
+			}
+			b, _ := ioutil.ReadAll(resp.Body)
+			body := string(b)
+			if _, ok := r.expectedStatusCodes[resp.StatusCode]; !ok {
+				t.Logf("case %v", r)
+				t.Errorf("Expected status one of %v, but got %v", r.expectedStatusCodes, resp.StatusCode)
+				t.Errorf("Body: %v", body)
+			}
+			if !strings.Contains(body, "\"apiVersion\":\""+r.expectedVersion) {
+				t.Logf("case %v", r)
+				t.Errorf("Expected version %v, got body %v", r.expectedVersion, body)
+			}
+		}()
+	}
+}
+
 func TestAccept(t *testing.T) {
 	_, s := framework.RunAMaster(t)
 	// TODO: Uncomment when fix #19254