In a given year, just 5 percent of the U.S. population is responsible for 50 percent of the nation’s medical spending. So who are these “super-users?” In this animation by Yukai Du we explore this incredibly diverse, constantly changing population and the efforts to address their enormous expenditures.

This video is part of The Atlantic’s project, “The Platinum Patients,” which is a collaboration with the Solutions Journalism Network, and is supported by a grant from the Commonwealth Fund.