British Para-triathlete Dave Ellis says he is devastated after his category was left out of the 2016 Rio programme.
The sport is making its Paralympic debut in Rio but only six of the sport's 10 categories will be included.
Ellis's male PT5 category for blind and visually impaired athletes is among those to miss out.
"It is so disappointing. It's like all the dreams and everything I've put into the sport has just been taken away," he told BBC Sport.
"I'm not really sure what is going to happen now. Being a full-time athlete has been my whole life and I really don't know what direction to go in. I now have some pretty big decisions to make."
Ellis, 28, who is originally from Derbyshire, represented Great Britain in swimming at the 2008 Beijing Paralympics but missed out on a place in the team at London 2012.
He took up para-triathlon in 2013 after attending a Talent ID day and won European and World gold that year along with his guide Luke Watson and claimed European silver this year.
|Para-triathlon will make its Paralympic debut in Rio along with Para-canoe|
|The race for all categories comprises a 750m swim, followed by 20km cycling and a 5km run|
|Athletes may use a hand cycle, tandem bicycle or bicycle in the cycling portion and wheelchairs are permitted on the running portion of the course.|
|GB's Lauren Steadman (PT4) and Alison Patrick (PT5) both won gold at the 2014 World Championships|
Earlier this year, the International Paralympic Committee and the International Triathlon Union decided on the first three of the six classes to be included in Rio and finalised the programme on Monday.
The classes to be included are the men's PT1 (wheelchair user) and PT2 and PT4 (physical impairments) while the women's programme will feature the PT2 and PT4 classes as well as a PT5 event.
As well as Ellis, the decision also means heartbreak for Britain's three-time world champion in the women's PT1 category Jane Egan.
"We knew that there would be classes who would miss out but I thought mine was one of the more competitive ones," added Ellis. "I think the top five or six could all win and it would have been a great race to have in Rio.
"As elite athletes, you put your life on hold and give everything because you know the Paralympics is such a massive occasion.
"When I didn't make the swimming team for London it was because I didn't make the qualifying time and I could understand it. But this time I've done well in the sport and think you will have the chance to qualify and when that is taken away from you it is gutting and hard to deal with again.
"I now need to see if there are any opportunities open to me in other sports and hope that there is something there."