UnitedHealth’s Expansion Strategy Is Threatened by US Regulators

UnitedHealth Group Inc., the giant US health-care conglomerate that insures nearly 46 million Americans, reaches into almost every corner of the health system. Beyond the insurer it’s best known for, the company, through its Optum services unit, runs a pharmacy benefit manager that fills 1.4 billion prescriptions annually. It also operates the country’s largest physician workforce—more than 60,000 doctors. Early last year, UnitedHealth bid to expand its reach by purchasing Change Healthcare Inc., a health technology business that operates critical systems for moving data and money between medical providers and insurers—including many of UnitedHealth’s rivals.

To gain its ...