The 21-year-old arrived at Portman Road from non-league side Chippenham Town back in 2012.
The left-back has only featured on 17 occasions this season due to the form of Aaron Cresswell, but McCarthy has insisted that Mings is a valuable member of his squad.
"I've said on numerous occasions how much I like Ty," McCarthy is quoted as saying by the East Anglian Daily Times. "He's taken the step up to this level in his stride and I've had to speak to him a couple of times because I think, in lots of other teams, he'd be playing. Here, though, he's behind the best left-back in the league."
Mings was released as a youngster in 2009 by Premier League side Southampton.