diff --git a/build/visible_to/BUILD b/build/visible_to/BUILD
index ff06d6aea7a..e850a3e040f 100644
--- a/build/visible_to/BUILD
+++ b/build/visible_to/BUILD
@@ -435,6 +435,7 @@ package_group(
         "//staging/src/k8s.io/apiserver/pkg/util/flowcontrol/metrics",
         "//staging/src/k8s.io/component-base/metrics/...",
         "//test/e2e_node",
+        "//test/integration/apiserver/flowcontrol",
         "//vendor/...",
     ],
 )
diff --git a/staging/src/k8s.io/component-base/metrics/BUILD b/staging/src/k8s.io/component-base/metrics/BUILD
index 4da26f4d462..99d652ae35a 100644
--- a/staging/src/k8s.io/component-base/metrics/BUILD
+++ b/staging/src/k8s.io/component-base/metrics/BUILD
@@ -93,6 +93,7 @@ package_group(
         "//staging/src/k8s.io/apiserver/pkg/util/flowcontrol/metrics",
         "//staging/src/k8s.io/component-base/metrics/...",
         "//test/e2e_node",
+        "//test/integration/apiserver/flowcontrol",
         "//vendor/...",
     ],
 )
diff --git a/test/integration/apiserver/BUILD b/test/integration/apiserver/BUILD
index 6a5f46fb8f2..4e96ba3f20b 100644
--- a/test/integration/apiserver/BUILD
+++ b/test/integration/apiserver/BUILD
@@ -90,6 +90,7 @@ filegroup(
         "//test/integration/apiserver/admissionwebhook:all-srcs",
         "//test/integration/apiserver/apply:all-srcs",
         "//test/integration/apiserver/certreload:all-srcs",
+        "//test/integration/apiserver/flowcontrol:all-srcs",
         "//test/integration/apiserver/podlogs:all-srcs",
     ],
     tags = ["automanaged"],
diff --git a/test/integration/apiserver/flowcontrol/BUILD b/test/integration/apiserver/flowcontrol/BUILD
new file mode 100644
index 00000000000..fb107f7abb0
--- /dev/null
+++ b/test/integration/apiserver/flowcontrol/BUILD
@@ -0,0 +1,39 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_test")
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "concurrency_test.go",
+        "main_test.go",
+    ],
+    tags = ["integration"],
+    deps = [
+        "//pkg/master:go_default_library",
+        "//staging/src/k8s.io/api/flowcontrol/v1alpha1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/features:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
+        "//staging/src/k8s.io/client-go/kubernetes:go_default_library",
+        "//staging/src/k8s.io/client-go/rest:go_default_library",
+        "//staging/src/k8s.io/component-base/featuregate/testing:go_default_library",
+        "//test/integration/framework:go_default_library",
+        "//vendor/github.com/prometheus/common/expfmt:go_default_library",
+        "//vendor/github.com/prometheus/common/model:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)
diff --git a/test/integration/apiserver/flowcontrol/concurrency_test.go b/test/integration/apiserver/flowcontrol/concurrency_test.go
new file mode 100644
index 00000000000..f6a30677549
--- /dev/null
+++ b/test/integration/apiserver/flowcontrol/concurrency_test.go
@@ -0,0 +1,317 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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.
+*/
+
+package flowcontrol
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/prometheus/common/expfmt"
+	"github.com/prometheus/common/model"
+
+	flowcontrolv1alpha1 "k8s.io/api/flowcontrol/v1alpha1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/wait"
+	genericfeatures "k8s.io/apiserver/pkg/features"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	clientset "k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
+	"k8s.io/kubernetes/pkg/master"
+	"k8s.io/kubernetes/test/integration/framework"
+)
+
+const (
+	sharedConcurrencyMetricsName      = "apiserver_flowcontrol_request_concurrency_limit"
+	dispatchedRequestCountMetricsName = "apiserver_flowcontrol_dispatched_requests_total"
+	labelPriorityLevel                = "priorityLevel"
+	timeout                           = time.Second * 10
+)
+
+func setup(t testing.TB) (*httptest.Server, *rest.Config, framework.CloseFunc) {
+	opts := framework.MasterConfigOptions{EtcdOptions: framework.DefaultEtcdOptions()}
+	opts.EtcdOptions.DefaultStorageMediaType = "application/vnd.kubernetes.protobuf"
+	masterConfig := framework.NewIntegrationTestMasterConfigWithOptions(&opts)
+	resourceConfig := master.DefaultAPIResourceConfigSource()
+	resourceConfig.EnableVersions(schema.GroupVersion{
+		Group:   "flowcontrol.apiserver.k8s.io",
+		Version: "v1alpha1",
+	})
+	masterConfig.GenericConfig.MaxRequestsInFlight = 1
+	masterConfig.GenericConfig.MaxMutatingRequestsInFlight = 1
+	masterConfig.GenericConfig.OpenAPIConfig = framework.DefaultOpenAPIConfig()
+	masterConfig.ExtraConfig.APIResourceConfigSource = resourceConfig
+	_, s, closeFn := framework.RunAMaster(masterConfig)
+
+	return s, masterConfig.GenericConfig.LoopbackClientConfig, closeFn
+}
+
+func TestPriorityLevelIsolation(t *testing.T) {
+	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, genericfeatures.APIPriorityAndFairness, true)()
+	// NOTE: disabling the feature should fail the test
+	_, loopbackConfig, closeFn := setup(t)
+	defer closeFn()
+
+	loopbackClient := clientset.NewForConfigOrDie(loopbackConfig)
+	noxu1Client := getClientFor(loopbackConfig, "noxu1")
+	noxu2Client := getClientFor(loopbackConfig, "noxu2")
+
+	queueLength := 50
+	concurrencyShares := 1
+
+	priorityLevelNoxu1, _, err := createPriorityLevelAndBindingFlowSchemaForUser(
+		loopbackClient, "noxu1", concurrencyShares, queueLength)
+	if err != nil {
+		t.Error(err)
+	}
+	priorityLevelNoxu2, _, err := createPriorityLevelAndBindingFlowSchemaForUser(
+		loopbackClient, "noxu2", concurrencyShares, queueLength)
+	if err != nil {
+		t.Error(err)
+	}
+
+	sharedConcurrency, err := getSharedConcurrencyOfPriorityLevel(loopbackClient)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if 1 != sharedConcurrency[priorityLevelNoxu1.Name] {
+		t.Errorf("unexpected shared concurrency %v instead of %v", sharedConcurrency[priorityLevelNoxu1.Name], 1)
+	}
+	if 1 != sharedConcurrency[priorityLevelNoxu2.Name] {
+		t.Errorf("unexpected shared concurrency %v instead of %v", sharedConcurrency[priorityLevelNoxu2.Name], 1)
+	}
+
+	stopCh := make(chan struct{})
+	defer close(stopCh)
+
+	// "elephant"
+	streamRequests(concurrencyShares+queueLength, func() {
+		_, err := noxu1Client.CoreV1().Namespaces().List(context.Background(), metav1.ListOptions{})
+		if err != nil {
+			t.Error(err)
+		}
+	}, stopCh)
+	// "mouse"
+	streamRequests(3, func() {
+		_, err := noxu2Client.CoreV1().Namespaces().List(context.Background(), metav1.ListOptions{})
+		if err != nil {
+			t.Error(err)
+		}
+	}, stopCh)
+
+	time.Sleep(time.Second * 10) // running in background for a while
+
+	reqCounts, err := getRequestCountOfPriorityLevel(loopbackClient)
+	if err != nil {
+		t.Error(err)
+	}
+
+	noxu1RequestCount := reqCounts[priorityLevelNoxu1.Name]
+	noxu2RequestCount := reqCounts[priorityLevelNoxu2.Name]
+
+	// Theoretically, the actual expected value of request counts upon the two priority-level should be
+	// the equal. We're deliberately lax to make flakes super rare.
+	if (noxu1RequestCount/2) > noxu2RequestCount || (noxu2RequestCount/2) > noxu1RequestCount {
+		t.Errorf("imbalanced requests made by noxu1/2: (%d:%d)", noxu1RequestCount, noxu2RequestCount)
+	}
+}
+
+func getClientFor(loopbackConfig *rest.Config, username string) clientset.Interface {
+	config := &rest.Config{
+		Host:        loopbackConfig.Host,
+		QPS:         -1,
+		BearerToken: loopbackConfig.BearerToken,
+		Impersonate: rest.ImpersonationConfig{
+			UserName: username,
+		},
+	}
+	return clientset.NewForConfigOrDie(config)
+}
+
+func getMetrics(c clientset.Interface) (string, error) {
+	resp, err := c.CoreV1().
+		RESTClient().
+		Get().
+		RequestURI("/metrics").
+		DoRaw(context.Background())
+	if err != nil {
+		return "", err
+	}
+	return string(resp), err
+}
+
+func getSharedConcurrencyOfPriorityLevel(c clientset.Interface) (map[string]int, error) {
+	resp, err := getMetrics(c)
+	if err != nil {
+		return nil, err
+	}
+
+	dec := expfmt.NewDecoder(strings.NewReader(string(resp)), expfmt.FmtText)
+	decoder := expfmt.SampleDecoder{
+		Dec:  dec,
+		Opts: &expfmt.DecodeOptions{},
+	}
+
+	concurrency := make(map[string]int)
+	for {
+		var v model.Vector
+		if err := decoder.Decode(&v); err != nil {
+			if err == io.EOF {
+				// Expected loop termination condition.
+				return concurrency, nil
+			}
+			return nil, fmt.Errorf("failed decoding metrics: %v", err)
+		}
+		for _, metric := range v {
+			switch name := string(metric.Metric[model.MetricNameLabel]); name {
+			case sharedConcurrencyMetricsName:
+				concurrency[string(metric.Metric[labelPriorityLevel])] = int(metric.Value)
+			}
+		}
+	}
+}
+
+func getRequestCountOfPriorityLevel(c clientset.Interface) (map[string]int, error) {
+	resp, err := getMetrics(c)
+	if err != nil {
+		return nil, err
+	}
+
+	dec := expfmt.NewDecoder(strings.NewReader(string(resp)), expfmt.FmtText)
+	decoder := expfmt.SampleDecoder{
+		Dec:  dec,
+		Opts: &expfmt.DecodeOptions{},
+	}
+
+	reqCounts := make(map[string]int)
+	for {
+		var v model.Vector
+		if err := decoder.Decode(&v); err != nil {
+			if err == io.EOF {
+				// Expected loop termination condition.
+				return reqCounts, nil
+			}
+			return nil, fmt.Errorf("failed decoding metrics: %v", err)
+		}
+		for _, metric := range v {
+			switch name := string(metric.Metric[model.MetricNameLabel]); name {
+			case dispatchedRequestCountMetricsName:
+				reqCounts[string(metric.Metric[labelPriorityLevel])] = int(metric.Value)
+			}
+		}
+	}
+}
+
+func createPriorityLevelAndBindingFlowSchemaForUser(c clientset.Interface, username string, concurrencyShares, queuelength int) (*flowcontrolv1alpha1.PriorityLevelConfiguration, *flowcontrolv1alpha1.FlowSchema, error) {
+	pl, err := c.FlowcontrolV1alpha1().PriorityLevelConfigurations().Create(context.Background(), &flowcontrolv1alpha1.PriorityLevelConfiguration{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: username,
+		},
+		Spec: flowcontrolv1alpha1.PriorityLevelConfigurationSpec{
+			Type: flowcontrolv1alpha1.PriorityLevelEnablementLimited,
+			Limited: &flowcontrolv1alpha1.LimitedPriorityLevelConfiguration{
+				AssuredConcurrencyShares: int32(concurrencyShares),
+				LimitResponse: flowcontrolv1alpha1.LimitResponse{
+					Type: flowcontrolv1alpha1.LimitResponseTypeQueue,
+					Queuing: &flowcontrolv1alpha1.QueuingConfiguration{
+						Queues:           100,
+						HandSize:         1,
+						QueueLengthLimit: int32(queuelength),
+					},
+				},
+			},
+		},
+	}, metav1.CreateOptions{})
+	if err != nil {
+		return nil, nil, err
+	}
+	fs, err := c.FlowcontrolV1alpha1().FlowSchemas().Create(context.TODO(), &flowcontrolv1alpha1.FlowSchema{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: username,
+		},
+		Spec: flowcontrolv1alpha1.FlowSchemaSpec{
+			DistinguisherMethod: &flowcontrolv1alpha1.FlowDistinguisherMethod{
+				Type: flowcontrolv1alpha1.FlowDistinguisherMethodByUserType,
+			},
+			MatchingPrecedence: 1000,
+			PriorityLevelConfiguration: flowcontrolv1alpha1.PriorityLevelConfigurationReference{
+				Name: username,
+			},
+			Rules: []flowcontrolv1alpha1.PolicyRulesWithSubjects{
+				{
+					ResourceRules: []flowcontrolv1alpha1.ResourcePolicyRule{
+						{
+							Verbs:        []string{flowcontrolv1alpha1.VerbAll},
+							APIGroups:    []string{flowcontrolv1alpha1.APIGroupAll},
+							Resources:    []string{flowcontrolv1alpha1.ResourceAll},
+							Namespaces:   []string{flowcontrolv1alpha1.NamespaceEvery},
+							ClusterScope: true,
+						},
+					},
+					Subjects: []flowcontrolv1alpha1.Subject{
+						{
+							Kind: flowcontrolv1alpha1.SubjectKindUser,
+							User: &flowcontrolv1alpha1.UserSubject{
+								Name: username,
+							},
+						},
+					},
+				},
+			},
+		},
+	}, metav1.CreateOptions{})
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return pl, fs, wait.Poll(time.Second, timeout, func() (bool, error) {
+		fs, err := c.FlowcontrolV1alpha1().FlowSchemas().Get(context.TODO(), username, metav1.GetOptions{})
+		if err != nil {
+			return false, err
+		}
+		for _, condition := range fs.Status.Conditions {
+			if condition.Type == flowcontrolv1alpha1.FlowSchemaConditionDangling {
+				if condition.Status == flowcontrolv1alpha1.ConditionFalse {
+					return true, nil
+				}
+			}
+		}
+		return false, nil
+	})
+}
+
+func streamRequests(parallel int, request func(), stopCh <-chan struct{}) {
+	for i := 0; i < parallel; i++ {
+		go func() {
+			for {
+				select {
+				case <-stopCh:
+					return
+				default:
+					request()
+				}
+			}
+		}()
+	}
+}
diff --git a/test/integration/apiserver/flowcontrol/main_test.go b/test/integration/apiserver/flowcontrol/main_test.go
new file mode 100644
index 00000000000..41cf0c86e8c
--- /dev/null
+++ b/test/integration/apiserver/flowcontrol/main_test.go
@@ -0,0 +1,27 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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.
+*/
+
+package flowcontrol
+
+import (
+	"testing"
+
+	"k8s.io/kubernetes/test/integration/framework"
+)
+
+func TestMain(m *testing.M) {
+	framework.EtcdMain(m.Run)
+}
diff --git a/test/integration/framework/BUILD b/test/integration/framework/BUILD
index 6b46ce43a6f..e0dfc1166f5 100644
--- a/test/integration/framework/BUILD
+++ b/test/integration/framework/BUILD
@@ -61,10 +61,13 @@ go_library(
         "//staging/src/k8s.io/apiserver/pkg/authorization/authorizerfactory:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/authorization/union:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/endpoints/openapi:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/features:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/server:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/server/options:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/server/storage:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/storage/storagebackend:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/flowcontrol:go_default_library",
         "//staging/src/k8s.io/client-go/informers:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes:go_default_library",
         "//staging/src/k8s.io/client-go/rest:go_default_library",
diff --git a/test/integration/framework/master_utils.go b/test/integration/framework/master_utils.go
index 52127655ce5..bfa88015e2b 100644
--- a/test/integration/framework/master_utils.go
+++ b/test/integration/framework/master_utils.go
@@ -39,10 +39,13 @@ import (
 	"k8s.io/apiserver/pkg/authorization/authorizerfactory"
 	authorizerunion "k8s.io/apiserver/pkg/authorization/union"
 	openapinamer "k8s.io/apiserver/pkg/endpoints/openapi"
+	genericfeatures "k8s.io/apiserver/pkg/features"
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	"k8s.io/apiserver/pkg/server/options"
 	serverstorage "k8s.io/apiserver/pkg/server/storage"
 	"k8s.io/apiserver/pkg/storage/storagebackend"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	utilflowcontrol "k8s.io/apiserver/pkg/util/flowcontrol"
 	"k8s.io/client-go/informers"
 	clientset "k8s.io/client-go/kubernetes"
 	restclient "k8s.io/client-go/rest"
@@ -191,6 +194,16 @@ func startMasterOrDie(masterConfig *master.Config, incomingServer *httptest.Serv
 	}
 
 	masterConfig.ExtraConfig.VersionedInformers = informers.NewSharedInformerFactory(clientset, masterConfig.GenericConfig.LoopbackClientConfig.Timeout)
+
+	if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.APIPriorityAndFairness) {
+		masterConfig.GenericConfig.FlowControl = utilflowcontrol.New(
+			masterConfig.ExtraConfig.VersionedInformers,
+			clientset.FlowcontrolV1alpha1(),
+			masterConfig.GenericConfig.MaxRequestsInFlight+masterConfig.GenericConfig.MaxMutatingRequestsInFlight,
+			masterConfig.GenericConfig.RequestTimeout/4,
+		)
+	}
+
 	m, err = masterConfig.Complete().New(genericapiserver.NewEmptyDelegate())
 	if err != nil {
 		// We log the error first so that even if closeFn crashes, the error is shown