She began training with the senior US National Team in the summer of 2018, while she was still in college. She was part of the team that won a gold medals in the 2019 FIVB Volleyball Women's Nations League tournament, as well as the 2019 Women's Pan-American Volleyball Cup. In May 2021, she was named to the 18-player roster for the 2021 FIVB Volleyball Women's Nations League. Poulter started the majority of the matches, and USA won the gold medal for the third straight year after defeating Brazil. She was named "Best Setter" at the conclusion of the tournament.