The Cuban program that exports doctors around the world qualifies as human trafficking according to a resolution introduced in the U.S. Senate on Thursday.
The resolution specifically mentions about 8,300 medical workers who had been stationed in Brazil under a contract with the Cuban government until recently.
The workers have since been pulled out by Cuba because of criticism from new Brazilian President Jair Bolsonaro, who called them "slave labor."
Bolsonaro objected to both the fact that the Cuban government keeps the vast majority of wages paid to the doctors and that they are not allowed to bring their families with them on assignments.
Cuba has a respected health service and generates major export earnings by sending more than 50,000 health workers to more than 60 countries.
The condemnation, introduced by Democrat Bob Menendez of New Jersey and Republican Marco Rubio of Florida is largely symbolic, intended to highlight the situation, not penalize anyone.
"Recent information from Brazil shows how the Cuban government profits from its state-sponsored foreign medical missions, which they sell as medical diplomacy but look a lot more like indentured servitude," Menendez said in a statement.
The Cuban doctors in Brazil were faced with a dire choice: apply for refugee status there and leave their families behind, or remain in what some of them called slavery.
The United States and Cuba have had a strained relationship since late leader Fidel Castro took over in a 1959 revolution.
While the United States restored diplomatic ties with the Caribbean island in 2015, large parts of an American economic embargo remain in place.
"It is outrageous, though not surprising, that the Cuban dictatorship continues to manipulate and traffic physicians in order to enrich itself," Rubio said in a statement.
"We must stand against the regime’s modern-day slavery scheme and support the doctors seeking justice after serving in these so-called international medical missions."