After making his Ulster debut against Leinster, in March 2013, McCall was awarded his first start against Newport Gwent Dragons in November 2015.
His first senior try came two months later in a nail-biting one point away victory over French side Oyonnax as the forward started five of Ulster's six European Champions Cup fixtures this season.
"I've thoroughly enjoyed coming through the system at Ulster Rugby," said the academy graduate.
"Personally, this season has been particularly pleasing because I have played a lot more than I expected to.
"I'm grateful to Les [Kiss] for giving me an opportunity to prove myself this year. To make my first senior start and then to get my first try were two very proud moments for me and my family.
"I want to continue to work hard to develop my core skills and try to push my game on to the next level.
"Hopefully I can cement a starting position next season and contribute to a successful Ulster team in both the PRO12 and Europe.
"Les is trying to build something special here and the players have really bought into it."
Head coach Les Kiss guided his side to fourth in the PRO12 standings this season but came unstuck at the RDS as Leinster won their semi-final.
With senior player of the season Stuart McCloskey signing a contract extension last week, Kiss is happy to see talent staying at Kingspan.
"His incessant work-rate has seen him earn a reputation as one of the best trainers in the squad," the head coach said of McCall.
"At 24, he is still young for a front row player, and with his huge potential and desire to be the best that he can be, I've no doubt that he can become a future international.
"I have to say, Bryn Cunningham [operations director] has done some great work in not only attracting world class talent like Marcell Coetzee and Charles Piutau to Ulster, but also in retaining our highly talented home-grown players."
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