The purchase will complement Express Scripts’ main business of managing prescription-drug benefits for health plans, employers and unions. The combination provides “significant opportunities for cross-selling to both client bases,” Express Scripts said in a statement.

Express Scripts said that the deal, which must be approved by regulators, is expected to close in the fourth quarter of 2017. EviCore will be run as a standalone business unit within Express Scripts, the company said.

Looming threats

Express Scripts shares have been under pressure recently amid renewed speculation that Amazon.com could move into pharmacy benefits, a development that could threaten Express Scripts and rivals including CVS Health Corp. and UnitedHealth Group Inc.’s OptumRx. Together, the three companies process about 70% of prescriptions in the U.S., according to Pembroke Consulting.

Amazon.com has never commented on whether it will enter the prescription-drug or drug-benefits market.

Meanwhile, Express Scripts is trying to prevent Anthem from severing ties when its current contract expires at the end of 2019. Anthem has accused Express Scripts of overcharging it by $3 billion a year and has said it expects to make a decision by year-end on what it will do. Express Scripts has denied overcharging Anthem.

If Anthem moves on, it will leave a huge hole in Express Scripts’ drug-benefits business. Anthem’s business made up about a third of the pharmacy-benefit manager’s earnings before interest, taxes, depreciation and amortization in the second quarter of 2017. Anthem owns an EviCore competitor called AIM Specialty Health.

The deal signals Express Scripts’ “desire to remain independent even with the likely Anthem loss, which may disappoint some catalyst-driven holders,” Eric Coldwell, an analyst at Robert W. Baird & Co. who has a neutral rating on Express Scripts shares, wrote in a note to clients. Combining management of prescription drugs and medical tests “is a logical expansion and key priority for health plans and employers.”

EviCore, which has about 4,000 employees, was created by the 2014 merger of two privately held companies, CareCore National LLC and MedSolutions Inc. Express Scripts is buying the company from investors including General Atlantic, TA Associates, and Ridgemont Equity Partners.

Lazard Ltd. and TripleTree LLC advised Express Scripts on the deal, while JPMorgan Chase & Co. and Morgan Stanley advised EviCore.