Andrew Slavitt, the outgoing acting administrator of CMS, previously worked as a senior executive at Optum. He announced this week he won't be going back to Optum or United Healthcare, at least for now. He will be staying in Washington to "help broker a deal" on Fixing Obamacare.
Story and interview at Politico, here.
Update: In March 2017, Slavitt announced plans to join the Bipartisan Policy Center (here).