Jossi Wells (18) was the first New Zealander to be invited to the games, competing as a 16-year-old in 2007.
He competed again last year, when he won a silver medal in the slopestyle competition.
This year, the brothers will compete in the half-pipe.
Byron has been competing well in the northern hemisphere, reaching the finals in each of the first Dew Tour events of the season in the US.
Byron said in a media release yesterday the X Games invitation had come out of the blue.
"I was sitting by myself on my computer when the email came through. It's a dream come true, I had the biggest smile on my face," he said.
Byron's father, Bruce Wells, said he was "stoked" for his second son, who had been living in Jossi's shadow and who deserved recognition for his own efforts.
Byron won the half-pipe and slopestyle events at last year's New Zealand Junior Nationals and was the highest-placed New Zealander in the New Zealand Freeski Open in August, when he finished in fifth place in the half-pipe.
The Wells brothers are members of the Freeski Association New Zealand national team and are supported by the NZ Winter Performance Programme.
The 13th annual Winter X Games begin in Aspen, Colorado on Thursday next week.
More than 160 athletes will be competing in the invitation-only event.
