In 2012, Carteris was elected as executive vice president of SAG-AFTRA, a trade union representing over 100,000 actors and other professionals mainly in the United States. She assumed the position of acting president of the union following the death of the previous president, Ken Howard, on March 23, 2016. On April 9, 2016, Carteris was elected SAG-AFTRA president by national board to serve out the remainder of Howard's term. She was re-elected to the position in August 2017 and August 2019 by full membership vote.