CVS-Aetna Deal Could Raise Drug Coverage Costs in Some Places

CVS Health Corp.’s proposed acquisition of insurer Aetna Inc. could attract the attention of the Justice Department because it appears likely to reduce competition in at least some of the Medicare prescription drug plan markets in which the two companies currently compete.

It would not only be a merger between the nation’s largest health insurer and its second largest pharmacy benefit manager and pharmacy chain, it would also be a merger between two major Medicare prescription drug plan administrators.

As the Justice Department weighs the deal, antitrust enforcers could be concerned that both companies sell Medicare Part D prescription drug ...