Matt Stone Racing has elevated Zane Goddard and Jake Kostecki, who shared the #34 entry in 2020, to full-time campaigns in 2020.
That forced Jacobson out the door at MSR, but he has been snaffled by Jonathon Webb's Tekno-led squad.
While all 24 full-time drivers have been confirmed, several co-driver slots are yet to be locked in.
Garth Tander and Craig Lowndes will return to Triple Eight, while Michael Caruso and James Golding will line up for Team 18.
Tim Blanchard will share his CoolDrive Racing entry with recruit Tim Slade, Thomas Randle returns to Tickford, while IndyCar-bound Scott McLaughlin is slated to return for DJR.
The new-look grid will make its first competitive appearance at the 2021 season opener, the Mt Panorama 500, across February 26-28.
2021 Repco Supercars Championship grid
Dick Johnson Racing
Will Davison
Anton De Pasquale
Triple Eight Race Engineering
Jamie Whincup
Shane van Gisbergen
Tickford Racing
Jack Le Brocq
Cameron Waters
James Courtney
Blanchard Racing Team
Tim Slade
Walkinshaw Andretti United
Chaz Mostert
Bryce Fullwood
Erebus Motorsport
Will Brown
Brodie Kostecki
Kelly Racing
Andre Heimgartner
David Reynolds
Brad Jones Racing
Nick Percat
Todd Hazelwood
Macauley Jones
Jack Smith