Once a proponent of Medicare Advantage plans, Oz vowed Friday to go after those plans if they unfairly raise costs for the government.

President Trump’s nominee to lead the Medicare agency criticized ‘upcoding,’ a business tactic of private insurers in the Medicare Advantage program that can boost federal payments.

Mehmet Oz breathlessly touted private Medicare plans on his popular daytime TV show and in the years that followed. On Friday, the former surgeon pledged with equal enthusiasm to crack down on widespread fraud within the program.