Going to voicemail if no one answers

Is it possible to set it up to where if no one answers it will go to voicemail? We have it setup to where if it will ring to person one, then if one doesn't answer it goes to person two then if two doesn't answer it goes to person three. If person three doesn't answer we want it to go to voicemail but instead it circles back to person one. Anyway to fix this? Thanks!