The 2004 Summer Olympics in Athens, Greece saw Sandeno win three more Olympic medals: a silver medal in the 400 m IM, a bronze medal in the 400 m freestyle, and a gold medal in the 4x200 m freestyle relay. The American team of Natalie Coughlin, Carly Piper, Dana Vollmer, and Sandeno also broke the seventeen-year-old world record (previously held by East Germany) by more than two seconds with their victory in the 4x200 m freestyle relay.
After failing to qualify for the 2008 U.S. Olympic Team, Sandeno announced her retirement. She is currently looking to start a new career in sports broadcasting. As of May 2010, Sandeno has joined with Think Physical Therapy and started a venture called Swim Tank where she will do stroke analysis for swimmers. For the 2010 Southern California Swim Season, Sandeno was an assistant swim coach at Mater Dei High School, a private catholic high school in Santa Ana, California. As a high school student, Sandeno attended a public high school in Lake Forest.