The U.S. Internal Revenue Service is seeking to use an infusion of funding to keep up with the ever-evolving tax maneuvers of the ultra-rich — while staving off frequent political attacks.

A pair of U.S. Internal Revenue Service agents are attempting to interview a billionaire they suspect of cheating on his taxes. But across the table from the agents is a formidable entourage of esteemed tax professionals hired to defend the billionaire. They include white-shoe attorneys — each of whom knows more about their own arcane corner of tax law than just about anyone on earth — along with highly specialized accountants and economists.

Neither of the two IRS agents has a law degree. Complex arguments from the billionaire’s entourage fly over their heads. The IRS agents are outmatched by a team whose combined years of experience in tax law and accounting exceed their own by over a century.

This stark example, laid out by former IRS officials in interviews with the International Consortium of Investigative Journalists, isn’t a hypothetical so much as a glimpse into the agency’s regular challenges in auditing the United States’ highest earners. These battles often come down to experience and expertise. The IRS has been losing, former officials said.

“The really experienced people tend to be on the outside [of the IRS],” Charles Rettig, who ran the IRS under former president Donald Trump and left the agency in 2022, told ICIJ. “That’s a major hurdle.”