A three-time Emmy winner, Waltz is formerly known for calling television broadcasts for the Miami Marlins of Major League Baseball from 2005 to 2017.

Waltz also called the 2020 AL Wild Card Series for TBS alongside Jimmy Rollins.

In 2018 Waltz called the NBA Playoffs and the NCAA Tournament East Regional on TNT's VR platform.

Waltz's ESPN assignments included the Women's NCAA basketball tournament, Arena Football, NCAA College Softball World Series, Little League World Series Regional Finals, and Major League Soccer.

In 2006, Waltz helped create and organize the FSN Fantasy Auction, which in 12 years raised more than $1.2 million for the Marlins Community Foundation.