Another blockbuster deal in healthcare.

Health insurer Centene is ponying up $15 billion to buy healthcare provider WellCare Health Plans.

The acquisition will give Centene scale, helping it better take on its rivals that have also bulked up through acquisitions: UnitedHealth, which bought Aetna, and Cigna, which acquired Express Scripts.

Together, Centene and WellCare will boast projected revenue of roughly $97 billion and serve 22 million members in all 50 states.

The combined company would be the third-largest health insurer in the U.S., according to Forbes, behind UnitedHealth and Anthem.

The purchase could also be an antidote to Centene's high dependence on Obamacare health plans.

The Trump administration moved last week to try again to undo the 2010 Affordable Care Act.

And if successful, that could abolish the Obamacare healthcare exchange, leaving Centene vulnerable.

The purchase of WellCare would let Centene move away from its reliance on the ACA, and grow its already big Medicaid business and expand into Medicare Advantage.

Investors drove up WellCare shares 10 percent Wednesday.

Centene shares dropped more than 8 percent at the market open.