The Defense Department said Monday the modification covers services for the Global Combat Support System-Army ERP program.
Work under the modification will run through April 13, 2019.
The Army Contracting Command has obligated $26.5 million in fiscal 2018 operations and maintenance funds at the time of the award.
Northrop helped the service branch deploy the first wave of GCSS-Army infrastructure to 281 warehouses after the Pentagon issued a full deployment decision in December 2012.
The web-based platform is designed to help the service branch manage financial and logistics functions.