diff --git a/content/en/docs/reference/access-authn-authz/service-accounts-admin.md b/content/en/docs/reference/access-authn-authz/service-accounts-admin.md
index 7e030903bc..c8f41806c9 100644
--- a/content/en/docs/reference/access-authn-authz/service-accounts-admin.md
+++ b/content/en/docs/reference/access-authn-authz/service-accounts-admin.md
@@ -59,6 +59,10 @@ It acts synchronously to modify pods as they are created or updated. When this p
   1. It adds a `volume` to the pod which contains a token for API access.
   1. It adds a `volumeSource` to each container of the pod mounted at `/var/run/secrets/kubernetes.io/serviceaccount`.
 
+Starting from v1.13, you can migrate a service account volume to a projected volume when
+the `BoundServiceAccountTokenVolume` feature gate is enabled.
+The service account token will expire after 1 hour or the pod is deleted. See more details about [projected volume](docs/tasks/configure-pod-container/configure-service-account/#service-account-token-volume-projection).
+
 ### Token Controller
 
 TokenController runs as part of controller-manager. It acts asynchronously. It: