No, ActorRefs cannot be looked up, which is why actorFor is going away; ActorRef is bound to an instance/incarnation while ActorPath logically is just about the names. ActorPath has also a “physical” function in locating an ActorRef—but this function is completely internal—and hence it carries the UIDs. In the mailing list discussion you linked to in another comment you make some good arguments why the UID should be stored together with the path: foremost it boils down to that ActorRefs don’t have parents.