Bob Costello announced today that he is leaving his role at the Cybersecurity and Infrastructure Security Agency (CISA) as chief information officer (CIO) and stepping away from federal service after more than two decades in government.
“I am sharing this post with reflection and gratitude,” Costello wrote in a post to LinkedIn. “With that perspective, this week marks my last at the Cybersecurity and Infrastructure Security Agency (CISA), closing an extraordinary chapter after 23 years of government service, including 18 years at the U.S. Department of Homeland Security (DHS).”
Costello’s resignation is unsurprising. According to reports, the former acting director of CISA, Madhu Gottumukkala, sought to suspend Costello in addition to several other officials who administered a polygraph test that Gottumukkala later failed.
While sources have told MeriTalk that Costello is well-liked across the agency, Cybersecurity Dive first reported that he was being reassigned to another DHS agency or given the option to resign.
“Serving as CIO at CISA has been one of the greatest privileges of my career. Together, we strengthened our cybersecurity posture, modernized critical systems, and built capabilities that will endure. I am incredibly proud of what we accomplished as a team,” Costello wrote.
He added, “To my team and current CISA leadership, you are exceptional professionals and even better people. I am rooting for you and have complete confidence that you will continue advancing this vital mission.”
In a statement shared with MeriTalk, Nick Andersen, CISA’s acting director, thanked Costello for his time within the federal government.
Andersen said that Costello’s “leadership as the … CIO has been instrumental in strengthening the Agency’s operational effectiveness, optimizing technology efficiencies, and advancing key priorities aligned with President Trump’s initiatives. We are grateful for his commitment, integrity, and impact—and we wish him the very best in his next chapter.”
Costello’s departure follows other recent CISA leadership shakeups. The CISA leadership directory on its website updated Chris Butera’s title as acting executive assistant director for cybersecurity.
Butera, who had been serving as the acting deputy executive assistant director for cyber, will step into the role last held by Andersen. Last week, CISA confirmed that Andersen stepped in as the agency’s new acting director after Gottumukkala departed for a different DHS role.
Butera is no stranger to CISA after working with the agency for 10 years. He previously served as the acting executive assistant director for cyber between May 2025 and September 2025, before Andersen joined CISA.
“As CISA’s senior career cybersecurity official, [Butera] is responsible for leading the agency’s mission to address the nation’s most significant cyber threats and vulnerabilities and to increase the security and resilience of U.S. critical infrastructure,” Butera’s updated biography on CISA’s website reads.
Costello’s departure and Butera’s new role fall amid a DHS shutdown after Democrats and Republicans have been unable to come to an agreement to reopen the agency.
CISA did not say who will be replacing Costello.