Dr. Mehmet Oz, President Donald Trump’s pick to lead the Centers for Medicare and Medicaid Services, will testify before the Senate Finance Committee on Friday morning.

Dr. Mehmet Oz, President Donald Trump’s nominee to oversee the Center for Medicare and Medicare Services, may have “significantly” underpaid Medicare and Social Security taxes.

Senate Finance Committee Democratic tax staff who reviewed Mehmet Oz’s tax returns said the nominee to run the Centers for Medicare and Medicaid Services avoided paying some Medicare and Social Security taxes over three years.