During last weekend's Abu Dhabi Grand Prix, reports had suggested that the Finn would leave the Enstone-based outfit before the end of the year after public contract wrangling, but Boullier told reporters that Raikkonen will race in Austin and at Interlagos.
He said: "He is completely on side. We all spoke in Abu Dhabi to make sure we know where we're going – and how we're getting there – for the final races of the year.
"It would obviously be fantastic if we could get both of our drivers back on the podium before the end of the season, and if they could both be there in Austin I'd be a very happy man."
Lotus are currently fourth in the constructors' standings, trailing second-place Mercedes by 37 points.