diff --git a/pkg/apis/core/annotation_key_constants.go b/pkg/apis/core/annotation_key_constants.go
index a1e6daae496..fb2751803e0 100644
--- a/pkg/apis/core/annotation_key_constants.go
+++ b/pkg/apis/core/annotation_key_constants.go
@@ -82,4 +82,10 @@ const (
 	//
 	// Not all cloud providers support this annotation, though AWS & GCE do.
 	AnnotationLoadBalancerSourceRangesKey = "service.beta.kubernetes.io/load-balancer-source-ranges"
+
+	// EndpointsLastTriggerTime is the annotation key, set for endpoints objects, that represents the
+	// timestamp of the last change that triggered the endpoints object update.
+	// This annotation will be used to compute the in-cluster network programming SLI. See
+	// https://github.com/kubernetes/community/blob/master/sig-scalability/slos/network_programming_latency.md
+	EndpointsLastTriggerTime = "kubernetes.io/endpoints.last-trigger-time"
 )
diff --git a/staging/src/k8s.io/api/core/v1/annotation_key_constants.go b/staging/src/k8s.io/api/core/v1/annotation_key_constants.go
index 16a0cfced13..f4830cbe199 100644
--- a/staging/src/k8s.io/api/core/v1/annotation_key_constants.go
+++ b/staging/src/k8s.io/api/core/v1/annotation_key_constants.go
@@ -78,4 +78,10 @@ const (
 	//
 	// Not all cloud providers support this annotation, though AWS & GCE do.
 	AnnotationLoadBalancerSourceRangesKey = "service.beta.kubernetes.io/load-balancer-source-ranges"
+
+	// EndpointsLastTriggerTime is the annotation key, set for endpoints objects, that represents the
+	// timestamp of the last change that triggered the endpoints object update.
+	// This annotation will be used to compute the in-cluster network programming SLI. See
+	// https://github.com/kubernetes/community/blob/master/sig-scalability/slos/network_programming_latency.md
+	EndpointsLastTriggerTime = "kubernetes.io/endpoints.last-trigger-time"
 )