The BCBS companies alleged that CVS had offered lower prices for "hundreds" of generic drugs and later told insurers that the prices were much higher than they actually were.

Blue Cross Blue Shield insurers in six states have sued CVS Health Corp. over an alleged scheme to overcharge them for generic drugs by submitting claims for payment at "inflated prices."

The lawsuit, filed May 27 in the Rhode Island federal court, added to mounting pressure that CVS has been facing since 2015 over its cash discount programs, which it said were designed to compete with Walmart and other "big-box" discounted pharmacies.

According to the complaint, health insurers typically negotiate "lesser-of" contracts with pharmacy benefits middlemen to pay the lower cost of either the negotiated drug price or the cash price that insured patients would pay. But the BCBS companies alleged that CVS had offered lower prices for "hundreds" of generic drugs and later told insurers that the prices were much higher than they actually were.