CVS Health Corp.'s $67.5 billion takeover of Aetna Inc. will test the Trump administration's approach to far-reaching corporate takeovers, just weeks after the U.S. government sued to block a major telecommunications merger.

The health-care deal unveiled Sunday would create an industry giant with over $240 billion in annual sales with a hand in insurance, prescription drug plan administration, retail pharmacies and corner clinics. The companies said the combination will save $750 million in costs and bring consumers better, more efficient health care.

In the past, deals combining companies up and down a chain of business—such as a supplier and a distributor—have been viewed as posing less anticompetitive risk than combinations of direct rivals. Last month, however, the Justice Department sued to block just such a "vertical" merger between AT&T Inc. and Time Warner Inc., saying it would harm consumers and limit their media content options.