As reported on Motorsports.com
Grist, 20, has raced in the Mazda Road to Indy since 2013 and won in each of his three seasons on the ladder.
He was third in USF2000 in 2013 with Andretti and carried on with the team in Pro Mazda in 2014, taking eighth overall and two victories.
A switch to Juncos followed in 2015 and, while the Canadian endured a slow start to the season, he claimed pole for four of the final six races and vaulted himself to third overall, with three wins to his name.
“We are very happy to have Grist back with us,” said team boss Ricardo Juncos. “In 2015, building a new Indy Lights team was very difficult for us – and that hurt the Pro Mazda team a little bit. We moved some technical stuff, we re-organised the whole thing.
“It took a while for us to learn and recover. It was a mutual process but, finally, in the second half of the season, we really started to put things together.
“It’s a great opportunity that allows us to keep working together for next year. Obviously we feel that he’s going to be a championship contender and we’ll just keep doing what we were doing last year.”
Grist will join fellow Juncos returnee Will Owen, as well as Pro Mazda rookies Nicolas Dapero and Jake Parsons, in the team.
“The end of the year last year was amazing, we won both races at Laguna and could’ve won a couple more but things happened,” Grist recalled.
“Like Ricardo said, we got off to a really slow start. We expected to be a dominant car from the first race of the year at St. Pete but, from Toronto on in the second half of the year, I think we were quickest in almost every session. Hopefully we can carry that onto this year.”