UnitedHealth Group Inc. said it expects major losses on its business through the Affordable Care Act's exchanges and will consider withdrawing from them, in the most prominent signal so far of health insurers' struggles with the health law's marketplaces.
The disclosure by the biggest U.S. health insurer, which had just last month sounded optimistic notes about the segment's prospects, will sharply boost worries about the sustainability of the law's signature marketplaces, amid signs that many insurers' losses on the business continue to mount.
