Amtrak No. 938 is an AEM-7 type electric locomotive built in collaboration by Electro-Motive Diesel (EMD) and ASEA in 1981 for the National Railroad Passenger Corporation, also known as Amtrak. It was used in high-speed passenger service on the electrified Northeast Corridor between Washington DC and Boston, MA. When Amtrak began replacing their AEM-7 locomotives with ACS-64 locomotives in February 2014, it was officially retired from service and placed in storage in Bear, DE.
In early June 2019, it was acquired by Caltrain, a commuter rail service in the San Francisco Bay Area, alongside sister AEM-7 locomotive 929. They both were then moved to Amtrak's Oakland Yard in Oakland, CA. 938 was chosen to be used for the testing process on Caltrain's electrification project while 929 was ultimately used as a source of spare parts for 938. Caltrain currently plans to complete their electrification project by September 2024, at which point, they will replace the vast majority of their old diesel-powered commuter trains with brand-new Stadler KISS bilevel electric multiple unit (EMU) trainsets. In December 2021, it was repainted into a Caltrain red and white paint scheme in preparation for the testing process.