Earlier this month, the federal Centers for Medicare & Medicaid Services (CMS) rejected Massachusetts’ plan to reduce its Medicaid expenditures on prescription drugs. Under the proposal, the state would have excluded expensive medications that were not proven to work better than other, cheaper alternatives.

In its rejection of the plan, the administration did not provide reasons why the state could not enact it, reported NPR’s Martha Bebinger.

“CMS rejected the proposal without much explanation beyond saying Massachusetts couldn’t do what it wanted and continue to receive the deep discounts drugmakers are required by law to give state Medicaid programs,” she wrote.

“Unfortunately, states are quite limited in what they’re able to do on their own, in terms of controlling prescription drug costs,” Washington University associate law professor Rachel Sachs told NPR.

And that’s especially burdensome, Sachs said, because each state must doubly bear high medication costs, “in its capacity as a public employer and its capacity as an insurer for the Medicaid population.”

Get the full story and Sachs’ analysis here, from NPR.