>> Is it an actual government agency?

Yes. In 2014, after the disastrous rollout of the Healthcare.gov site, President Obama created the "United States Digital Service" (USDS). Its stated mission was to modernize technology and improve efficiency across all US departments and agencies.

President Trump renamed the USDS to the "United States DOGE Service" (USDS) and created a temporary "Department of Government Efficiency" (DOGE) organization within the USDS that will operate until July 4, 2026.

Every US government agency is required to establish a DOGE team within that agency to work with the USDS to "improve the quality and efficiency of government-wide software, network infrastructure, and information technology (IT) systems".