Jimmy played on Dave Mustaine's (Megadeth Vocalist/Guitarist) solo album, MD-45 in 1995 and then received a call back from Mustaine, in 1998, to join Megadeth as a permanent member and continue the bands' Cryptic Writings Tour. DeGrasso recorded and toured behind Megadeth's Risk album in 1999-2000, The World Needs A Hero in 2000-2001 and was featured on Megadeths' first ever live CD and DVD offering, Rude Awakening in 2002.
Since the demise of Megadeth, Jimmy has performed at the prestigious Modern Drummer Festival in 2002, Ultimate Drummers Weekend in Australia, Drummer Live in the UK and toured with Stonesour [Slipknot Vocalist Corey Taylor's side project], guitar legend Ronnie Montrose and is a highly sought after session player and drum clinician around the world.