diff --git a/integration-tests/byoid/integration_test.go b/integration-tests/byoid/integration_test.go
index ae6e0e6f2c2..da3074c4233 100644
--- a/integration-tests/byoid/integration_test.go
+++ b/integration-tests/byoid/integration_test.go
@@ -142,13 +142,9 @@ func generateGoogleToken(keyFileName string) (string, error) {
 	return token.AccessToken, nil
 }
 
-// testBYOID makes sure that the default credentials works for
-// whatever preconditions have been set beforehand
-// by using those credentials to run our client libraries.
-//
-// In each test we will set up whatever preconditions we need,
-// and then use this function.
-func testBYOID(t *testing.T, c config) {
+// writeConfig writes a temporary config file to memory, and cleans it up after
+// testing code is run.
+func writeConfig(t *testing.T, c config, f func(name string)) {
 	t.Helper()
 
 	// Set up config file.
@@ -164,27 +160,46 @@ func testBYOID(t *testing.T, c config) {
 	}
 	configFile.Close()
 
-	// Once the default credentials are obtained,
-	// we should be able to access Google Cloud resources.
-	dnsService, err := dns.NewService(context.Background(), option.WithCredentialsFile(configFile.Name()))
-	if err != nil {
-		t.Fatalf("Could not establish DNS Service: %v", err)
-	}
+	f(configFile.Name())
+}
 
-	_, err = dnsService.Projects.Get(projectID).Do()
-	if err != nil {
-		t.Fatalf("DNS Service failed: %v", err)
-	}
+// testBYOID makes sure that the default credentials works for
+// whatever preconditions have been set beforehand
+// by using those credentials to run our client libraries.
+//
+// In each test we will set up whatever preconditions we need,
+// and then use this function.
+func testBYOID(t *testing.T, c config) {
+	t.Helper()
+
+	writeConfig(t, c, func(name string) {
+		// Once the default credentials are obtained,
+		// we should be able to access Google Cloud resources.
+		dnsService, err := dns.NewService(context.Background(), option.WithCredentialsFile(name))
+		if err != nil {
+			t.Fatalf("Could not establish DNS Service: %v", err)
+		}
+
+		_, err = dnsService.Projects.Get(projectID).Do()
+		if err != nil {
+			t.Fatalf("DNS Service failed: %v", err)
+		}
+	})
 }
 
 // These structs makes writing our config as json to a file much easier.
 type config struct {
-	Type                           string           `json:"type"`
-	Audience                       string           `json:"audience"`
-	SubjectTokenType               string           `json:"subject_token_type"`
-	TokenURL                       string           `json:"token_url"`
-	ServiceAccountImpersonationURL string           `json:"service_account_impersonation_url"`
-	CredentialSource               credentialSource `json:"credential_source"`
+	Type                           string                          `json:"type"`
+	Audience                       string                          `json:"audience"`
+	SubjectTokenType               string                          `json:"subject_token_type"`
+	TokenURL                       string                          `json:"token_url"`
+	ServiceAccountImpersonationURL string                          `json:"service_account_impersonation_url"`
+	ServiceAccountImpersonation    serviceAccountImpersonationInfo `json:"service_account_impersonation,omitempty"`
+	CredentialSource               credentialSource                `json:"credential_source"`
+}
+
+type serviceAccountImpersonationInfo struct {
+	TokenLifetimeSeconds int `json:"token_lifetime_seconds,omitempty"`
 }
 
 type credentialSource struct {
@@ -192,12 +207,12 @@ type credentialSource struct {
 	URL                         string           `json:"url,omitempty"`
 	Executable                  executableConfig `json:"executable,omitempty"`
 	EnvironmentID               string           `json:"environment_id,omitempty"`
-	RegionURL                   string           `json:"region_url"`
+	RegionURL                   string           `json:"region_url,omitempty"`
 	RegionalCredVerificationURL string           `json:"regional_cred_verification_url,omitempty"`
 }
 
 type executableConfig struct {
-	Command       string `json:"command"`
+	Command       string `json:"command,omitempty"`
 	TimeoutMillis int    `json:"timeout_millis,omitempty"`
 	OutputFile    string `json:"output_file,omitempty"`
 }
@@ -380,3 +395,58 @@ echo "{\"success\":true,\"version\":1,\"expiration_time\":%v,\"token_type\":\"ur
 		},
 	})
 }
+
+func TestConfigurableTokenLifetime(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test")
+	}
+
+	// Set up Token as a file
+	tokenFile, err := ioutil.TempFile("", "token.txt")
+	if err != nil {
+		t.Fatalf("Error creating token file:")
+	}
+	defer os.Remove(tokenFile.Name())
+
+	tokenFile.WriteString(oidcToken)
+	tokenFile.Close()
+
+	const tokenLifetimeSeconds = 2800
+	const safetyBuffer = 5
+
+	writeConfig(t, config{
+		Type:                           "external_account",
+		Audience:                       oidcAudience,
+		SubjectTokenType:               "urn:ietf:params:oauth:token-type:jwt",
+		TokenURL:                       "https://sts.googleapis.com/v1/token",
+		ServiceAccountImpersonationURL: fmt.Sprintf("https://iamcredentials.googleapis.com/v1/%s:generateAccessToken", clientID),
+		ServiceAccountImpersonation: serviceAccountImpersonationInfo{
+			TokenLifetimeSeconds: tokenLifetimeSeconds,
+		},
+		CredentialSource: credentialSource{
+			File: tokenFile.Name(),
+		},
+	}, func(filename string) {
+		b, err := ioutil.ReadFile(filename)
+		if err != nil {
+			t.Fatalf("Coudn't read temp config file")
+		}
+
+		creds, err := google.CredentialsFromJSON(context.Background(), b, "https://www.googleapis.com/auth/cloud-platform")
+		if err != nil {
+			t.Fatalf("Error retrieving credentials")
+		}
+
+		token, err := creds.TokenSource.Token()
+		if err != nil {
+			t.Fatalf("Error getting token")
+		}
+
+		now := time.Now()
+		expiryMax := now.Add(tokenLifetimeSeconds * time.Second)
+		expiryMin := expiryMax.Add(-safetyBuffer * time.Second)
+		if token.Expiry.Before(expiryMin) || token.Expiry.After(expiryMax) {
+			t.Fatalf("Expiry time not set correctly.  Got %v, want %v", token.Expiry, expiryMax)
+		}
+	})
+}