Triathlon is not an official NCAA sport. Right now, the only way to compete on the collegiate level is to join a club. It's the future that's different.

As of January 2014, women's triathlon is being considered for inclusion in the NCAA (source). It's officially an "emerging sport." That doesn't mean that it's coming out of the Mekong with a knife gripped between its teeth; it means that they're thinking about letting it in.

To get let in, there will need to be at least forty varsity triathlon teams within the next ten years. As of December 2014, there was one: Marymount University in Virginia. So it's not quite on pace to make it. That doesn't mean it won't, though.

Right now, there are no plans to make men's triathlon an event. This could change if fifty varsity teams spring into existence and submit their proposal, but there are no indications this is in the process of happening.