Exhibit 99.1 Telos Corporation Announces Substantial Progress on New Business Capture; Reports Fourth Quarter and Full Year 2023 Results Above Expectations • Telos’ Prime Partners Received Awards on New Programs Worth up to $525 Million to Telos’ Security Solutions Business Over Five Years, Subject to Customary Protest Periods and Favorable Resolution of Protests • Reports Fourth Quarter and Full Year 2023 Revenue, Profit, and Cash Flow Above Expectations • Delivered Fourth Quarter Revenue of$41.1 Million ...