With credit card fees taking a sizable bite of their billings, many U.S. health care providers are fighting back by offering patients cash discounts. But when a drug company covers card processing fees for its distributors to pass on to their provider clients so they can pay for so-called “buy-and-bill” Medicare Part B drugs with a credit card at cash prices, it’s fraud if those concessions aren’t figured into the drug’s average sales price – at least that’s what the U.S. Department of Justice is claiming in a complaint it released April 10 against Regeneron Pharmaceuticals Inc.