WASHINGTON—The Justice Department filed an antitrust lawsuit Thursday challenging UnitedHealth Group Inc.’s $13 billion acquisition of health-technology firm Change Healthcare Inc., arguing the tie-up would unlawfully reduce competition in markets for commercial insurance and the processing of claims.
The deal, announced in January 2021, sought to bring a major provider of healthcare clinical and financial services, including the handling of claims, under UnitedHealth’s Optum health-services arm.