The most successful junior single-seater team of recent years on the European ladder announced this week that it will combine its programmes in Formula 2, Formula 3, the Formula Regional European Championship by Alpine and various Formula 4 championships with a move into the US open-wheel scene next year.
It will enter a two-car team using engines from Chevrolet and base itself from a new headquarters in Indiana.
Piers Phillips will head up the operation as IndyCar CEO, following spells at Schmidt Peterson Motorsports and Rahal Letterman Lanigan Racing.
Facing the media following the announcement, alongside Phillips and IndyCar president Jay Frye, Rosin revealed that discussions over expanding into IndyCar had been ongoing for over two years.
Rosin acknowledges that its rookie season "will be a learning year" as it adapts to the unique combination of circuits on the IndyCar calendar that spans ovals as well as road and street courses, but feels the timing is right for Prema to "to expand our boundaries" following its move into sportscars in partnership with Iron Lynx to run the works Lamborghini SC63 programme in the World Endurance Championship.
Rosin said: "Why in '25? Of course, when Prema join a championship, it's not to join to be just a number or to be somebody part of it.
"We want to be part as a protagonist, we want to be part when we are ready to do something.
"'24 to '25 was the right time for us in terms of structures, all the other programmes we are doing, to setting up a new adventure here in the U.S."
Many facets of the team remain a work in progress, with the precise location of its US base yet to be confirmed.
Rosin anticipates his role "will evolve into a more overlooking" nature across both sides of the Atlantic, with Phillips responsible for the day-to-day operation of the IndyCar team.
The English engineer explained that "the core of the team will have experience" in the championship, but plans to look "at blending the talents from both sides of the Atlantic".
Phillips added that the expectation for Prema is to be competitive from the outset as the team is starting "from a really strong foundation".
"There's some very, very strong, top-level teams in this championship, we know that," he said. "But it is our desire that we will come in and we want to be competitive right from the word 'go'.
"I know that's a big ask, but we will be working extremely hard in putting all our efforts from the start of the programme."
Rosin was coy when asked about the team's planned driver line-up, but pledged that "soon we will have some news".
Several Prema graduates currently compete in IndyCar, including Chip Ganassi Racing's Marcus Armstrong and Meyer Shank Racing driver Felix Rosenqvist.
"If I can say for sure, ideally it will be good to have an experienced drivers and of course one rookie," said Rosin.
"On the other hand, as Prema, we always work with rookies, we always maximise the result. We are not scared to even have two rookies.
"We are really evaluating all the opportunity to maximise what is our potential.
"I think this is now the next step on what we will dedicate most of our time together to building up the team in the best ways possible."
