The chief medical officer at Customs and Border Protection has resigned, leaving the crucial role at the agency empty for the third time in roughly three years, our sister outlet PunchUp has learned.
Margaret Brewinski Isaacs informed her colleagues of her decision to leave CBP after about a year in the position during a staff meeting on March 25. According to multiple sources, she told colleagues she did not feel she was a “good fit” for the role.
CBP told the Daily Beast that Brewinski Isaacs had been “recruited by another federal agency and accepted a position,” which is understood to be at the U.S Food and Drug Administration. Brewinski Isaacs did not respond to a request for comment.
PunchUp reports that Brewinski Isaacs’ exit yet again leaves CBP without a substantive leader of its Office of the Chief Medical Officer (OCMO)—whose central mandate includes ensuring that migrants in custody receive adequate medical care—and further adds to the dysfunction within America’s largest federal law enforcement agency.
“This is just another example of the organizational rot that courses through all levels of CBP leadership,” one DHS source told the investigative outlet.
Brewinski Isaacs, a pediatrician known as “Maggie,” with no known law-enforcement or military operational medicine background, was brought in as CMO from the HHS’s Office of Refugee Resettlement. She replaced a non-medical stopgap from the Office of Field Operations, who had been filling in since her predecessor’s departure.
The CMO role was created in 2020. Its inaugural holder, Dr. David Tarantino, was reassigned in June 2023 in the wake of the death of Anadith Danay Reyes Alvarez, an eight-year-old girl who died at a Border Patrol station in Harlingen, Texas, after CBP contractors repeatedly refused her mother’s pleas for emergency medical treatment. Tarantino was never accused of wrongdoing or found culpable. Tarantino did not answer a request for comment.
His replacement, Dr. Alexander Eastman, 51, was removed from CBP headquarters in December 2024, within 18 months of joining, following whistleblower-led allegations of misconduct. Eastman’s lawyer told the Beast: “He has admitted where he has been in error and has accepted responsibility where he unintentionally engaged in minor policy violations.”
The latest upheaval arrives as CBP continues to reel from a period of extraordinary institutional turbulence.
Former DHS Secretary Kristi Noem, 54, and her then-special government employee and rumored lover, Corey Lewandowski, 52, waged what sources described to the Washington Examiner as an “evil” campaign to sideline CBP Commissioner Rodney Scott—a 30-year law enforcement veteran—in favor of Border Patrol’s hardline commander at large, Gregory Bovino, 56.
Bovino was handed a back-channel reporting line straight to Noem and Lewandowski that cut Scott out entirely. Bovino was fired after his team caused chaos in Minneapolis, Minnesota, where two U.S. citizens were killed by federal agents in January.
Lewandowski then installed attorney Joseph Mazzara—a man with no prior law enforcement experience—as CBP Deputy Commissioner in December 2025, in what DHS insiders told the Beast was a deliberate bid to run Scott’s own agency over his head. “He was Corey’s henchman and sought to fire anyone not loyal to Noem, Corey and Trump,” one DHS source told the Beast.
Trump fired Noem on Mar. 5 following two days of bruising congressional hearings centered on the deaths of unarmed mother Renee Nicole Good and VA ICU nurse Alex Pretti during ICE operations in Minneapolis, and on hundreds of millions of dollars in questionable DHS contracts. Mazzara was walked out of the DHS building days later. Lewandowski then followed.
DHS is now led by former Oklahoma senator Markwayne Mullin, 48.
A CBP spokesperson told the Beast that the agency “abides by strict legal and humanitarian standards, with processing facilities’ continuous internal and external monitoring to ensure proper medical care, nutrition, welfare checks, and humane conditions.”
Head to PunchUp for the full, exclusive reporting.
