The Unión Médica Nacional has joined striking anesthesiologists in a strike at public hospitals.
More negotiations are expected today to end the standoff.
The Caja Costarricense del Seguro Social operates the public hospitals, and officials there say that more than 2,000 surgeries have had to be postponed.
Tuesday was the first day that other doctors staged a walkout. The strike was not 100 percent effective, and public opinion is running against the physicians. The medical union joined the strike after two anesthesiologist were fired.