President Donald Trump's pick for IRS commissioner is moving on. Here's who else has had the job this year and why they left.

Billy Long, who was sworn in just under two months ago, was already the sixth person to hold the job this year. He told NBC News he will be the next U.S. ambassador to Iceland.

President Donald Trump is ousting Billy Long from his role as commissioner of the Internal Revenue Service just two months after he was confirmed to the position, three sources familiar told CNN.