Keith Tannenbaum is the Chief Executive Officer of Atlantic Net, the primary insurance company providing revenue to Princeton-Plainsboro Teaching Hospital. He appears in the Season 6 episode 5 to 9. He is portrayed by actor Patrick St. Esprit. When Cuddy was in a fee dispute with Atlantic Net, she wondered if she should go over the head of their chief negotiator Eli Morgan after she threatened to cut off their contract. However, she didn't know where to find Tannenbaum until she turned to her then boyfriend Lucas Douglas.