A plan proposed by the Obama administration to test how limiting prescription drug payments might help lower excessive spending has been met with swift opposition from physicians, providers, drug manufacturers and healthcare organizations.

Released earlier this week, the proposal calls for a series of tests using alternative methods of paying for Medicare Part B drugs, which accounted for more than $20 billion in treatments received by patients inside physicians’ offices in the past year alone.

Among those unhappy with the proposal are cancer centers and oncologists, who say the tests put financial interests above healthcare access and quality for patients.

“It’s insulting. It’s really infuriating,” Robin Zon, MD, of Michiana Hematology-Oncology P.C. in South Bend, Ind., told the Wall Street Journal. “This is an experiment, and it’s an experiment that will affect lives. I am so afraid this will do more harm than good.”

There has also been opposition to the White House’s plan among lawmakers and advocacy groups, some of whom are concerned that with the rise of tailored treatments and patient-specific care, women and minority groups in particular will suffer from tinkering with the drug payment system.

“We’re moving into an era of personalized medicine,” Leslie Ritter, vice president of the Society for Women’s Health and Research told the New York Times. “The primary focus should be on the patient, not on costs. In many cases, we don’t know what works best for patients because women and members of minority groups were not adequately represented in clinical trials.”

The tests wouldn’t be instituted until after a proposal a 60-day comment period, but if approved, providers would be grouped based on service areas, with some remaining under the existing payment system and others undergoing changes in prices, premiums and fees as part of the payment plan testing over the next five years.