The Defense Information Systems Agency (DISA) is seeking sources for mainframe and legacy system modernization services. The goal is to support the modernization of a wide variety of mainframe and legacy systems used for critical tasks such as managing logistics, finances, personnel, and command and control. The anticipated Period of Performance is from December 1, 2026, to November 30, 2031. The required capabilities include code modernization, mainframe data ecosystem transformation, mainframe to hybrid cloud transformation, DoD security accreditation and authority to operate, legacy system API enablement, mainframe AI/ML implementation, and testing and transition management. • Code modernization: transforming complex legacy IBM Mainframe application code into high-performing, maintainable, and scalable modern languages. • Mainframe data ecosystem transformation: transforming legacy IBM Mainframe data environments, including storage, access, sharing, and governance of data. • Mainframe to hybrid cloud transformation: integrating on-premises systems with cloud platforms. • DoD security accreditation and authority to operate: ensuring compliance with the highest cybersecurity standards. • Legacy system API enablement: exposing data and functionality from legacy IBM Mainframe systems through secure and scalable Application Programming Interfaces (API). • Mainframe AI/ML implementation: embedding Artificial Intelligence (AI), Machine Learning (ML), and automation directly into the IBM Mainframe environment. • Testing and transition management: ensuring modernized IBM Mainframe systems are reliable and secure through a rigorous testing and transition process.