He will lead delivery teams and help establish relationships with federal customers in his new position, the company said Thursday.
Marglin spent more than 17 years at Booz Allen and previously managed a digital team within the firm's strategic innovation group and its civil/fed market area.
He provided IT support services to state and local government clients during his tenure at American Management Systems.
Herndon, Va.-based Karsun won an $80M blanket purchase agreement in April to update the Federal Emergency Management Agency's grants processing system.
Karsun added its partnership with Mindcubed holds a spot on a potential $2.5B Securities and Exchange Commission IT contract vehicle.