From Bloomberg:

UnitedHealth will “watch and see” how the exchanges evolve and expects the first enrollees will have “a pent-up appetite” for medical care, Hemsley said. “We are approaching them with some degree of caution because of that.”

An interpretation from Think Progress:

Get that? The company packed its bags and dumped its beneficiaries because it wants its competitors to swallow the first wave of sicker enrollees only to re-enter the market later and profit from the healthy people who still haven’t signed up for coverage.

Advertisement