Janitors at Walter Reed National Military Medical Center protested outside the facility Tuesday.
The janitors say they haven't been paid in more than two weeks.
The janitors are not paid by Walter Reed. They are contracted to work at the facility by ESCAB Enterprises. The Service Employees International Union that represents the workers says it hasn't been made clear when the workers will get paid again.
SEIU says Escab Enterprises has received more than $40 million in federal contracts since 2008.
The union is asking the federal government to stop paying ESCAB until they pay workers.
The union workers say they are hesitant to strike because they are concerned about patients at the facility.