The limited plan would, for the first time, give Medicare the power to negotiate prices directly with pharmaceutical companies.
A federal judge has issued an injunction to the Medicare rule change, saying the administration rushed it through.
The president is expected to meet with pharmaceutical industry executives, who are opposed to the changes, on Tuesday.
Some members of Congress feel the measure might go too far. Drug companies don't like it, either.
The answer comes down to one key tactic: negotiation.
The idea is that transparency would lead to more competition and lower costs. One drug company is already on board.
Prescription drug prices have been rising over the past few years.
The trade agreement reached over the weekend between the U.S., Canada and Mexico includes longer intellectual property protection periods for the expensive class of drugs known as biologics.