Chinese President Xi Jinping will meet with Obama next month.
"An estimated 4 million doses expire unused each year," they say.
Rubio said Obama's Cuba policy is sending a "demoralizing message" to dissidents.
Sen. Charles Grassley wants to know why Cuba is not taking back convicted nationals.
The 2016 contender introduced legislation that would create a "Federal Election Day."
Paul is highlighting the program as part of "waste report."
The senators pointed to a recent uptick in threats against troops.
The move would make the program available to all veterans currently receiving VA care.
With lawmakers focused on Iran and 2016 looming, its unclear when Congress will act.
The State Department lifted a ban earlier this year.