The fight is heating up in the push to reform the federal 340B drug discount program to reduce the out-of-pocket costs to Medicare enrollees and other participants. The pharmaceutical industry is now weighing in on rising out-of-pocket costs due to 340B hospitals shifting patients to more expensive sites of care.

An analysis of Medicare Fee-for-Service claims data by the Berkeley Research Group shows a substantial shift in site of care for outpatient drug therapies from the physician office to the 340B hospital outpatient setting from 2008 to 2015, according to the report, "Site of Care Shift for Physician-Administered Drug Therapies," commissioned by the Pharmaceutical Research and Manufacturers of America.

For breast cancer and multiple myeloma medicines, about 33 percent of all Part B sales were at 340B hospitals by 2015, compared to 11 or 12 percent in 2008. About 19 percent of the rheumatoid arthritis drug sales through Part B were to 340B hospitals in 2015, compared to 6 percent in 2008.