UnitedHealth Group

2016 Revenue: $184.8 billion

America’s largest health insurer, UnitedHealth (unh, +1.36%), has been on a steady upward climb since CEO Stephen Hemsley took the helm in 2006, and 2016 was no different. Revenue was up 17.7% from a year earlier, despite losses from its involvement in the Affordable Care Act healthcare exchanges. United has said that it will exit most ACA state exchanges by the end of 2017. Meanwhile, its technology and services division, Optum, is expected to continue driving United’s earnings growth.