On 27 June 2017, Moxey signed a three-year contract with his former club. He made his second debut for the club against Barnet FC, coming off the bench in the 95th minute for Rueben Reid in a 2-1 win for Exeter. Dean became a key part of Exeter's side, playing at left back, centre back and left midfield, playing 42 games in total. He started in the 2018 EFL League Two Playoff Final at Wembley for Exeter, which they lost 3–1 to Coventry City. In the 2018/19 season, Dean was promoted to vice-captain of Exeter after Jayden Stockley's departure to Preston North End. He made 39 more appearances that season, also picking up two red cards, primarily playing at centre-back under new manager Matt Taylor. Dean made his 300th appearance for the club in a 3–3 draw against Walsall on 21 December 2019. Moxey was released by Exeter at the end of his contract in July 2020, his final appearance came in the 2020 EFL League Two Playoff Final at Wembley.