The Justice Department is suing to block UnitedHealth Group's $3.3 billion purchase of Amedisys, citing concerns the combination would hinder access to home health and hospice services in the U.S.

UnitedHealth is seeking to add Amedisys to Optum, its subsidiary that provides care as well as pharmacy and technology services.

Amedisys Inc. and its affiliates (Amedisys) have agreed to pay $150 million to the federal government to resolve allegations that they violated the False Claims Act by submitting false home healthcare billings to the Medicare program.