Phelps talks transitioning From Olympian to entrepreneur

With 28 medals, Michael Phelps is the most-decorated Olympic athlete of all time, and since his final appearance at Rio's 2016 Summer Olympics, he has moved on to entrepreneurship.

The decorated Olympian participated in Forbes' "30 Under 30 Summit" on Tuesday, and told CNBC's "Closing Bell" how he shared about "starting with a goal and a dream and hard work and dedication, and believing that I could do something that basically everybody else said was impossible."

Phelps' success has also translated into numerous sponsorships and deals with companies such as Aqua Sphere, Omega, Under Armour and Beats by Dre.

When asked how he chooses which companies to partner with or sponsor, Phelps said, "If you look at the partners that i have, it is everything that fits into my life. I think every company that I'm with fits into my personal life and just really how I go about my day."

From money earned through his successful athletic career and sponsors, Phelps was able to establish the Michael Phelps Foundation. Within the foundation, he developed a program called the IM Program, aimed toward kids who wouldn't normally have access to learning how to swim.

"Drowning for children under the age of 14 is the second highest cause of death. And that has to change," Phelps said. "Being retired again, I have a lot more time to be able to travel a lot to these different sites and hopefully be able to have an impact with children and learn to swim."

Phelps has also been able to establish his own swimwear brand called MP, with designed suits, which he also wore in Rio. The swimmer is reported to have new designs prepared in 2017 as well.

When asked about whether he may be expanding beyond entrepreneurship and branching out into equity investments or venture capitals, Phelps responded, "You never know what can happen. I love to get involved in small things on the side and have fun with stuff. I guess only time will tell. But I would love to ring the bell [at the New York Stock Exchange]."

However for now, Phelps expressed his desire on focusing on his family and enjoying life at home with his son and fiancee.