After three years at CERN, Carena was hired by Fermilab in an associate scientist position, and was later promoted to a full tenured scientist role. At Fermilab, Carena originated a visitor program which brings students from Latin America to Fermilab so that they can pursue research projects with Fermilab theoretical physicists as part of their graduate education. In 2008, she began a formal teaching position at the University of Chicago.