For many of President Donald Trump’s business assets, a trail of limited liability companies create a path from the asset to the Donald J. Trump Revocable Trust, which collects the income from his international businesses. This type of business structure is not uncommon and is considered to be smart corporate tax planning.

Bloomberg Businessweek reports that somewhere between the asset and the trust, an S corporation is utilized. With an S corporation, active owners who pay themselves “reasonable” compensation for running the company avoid the net investment income tax on their share of the corporation’s profits by paying the 3.8-percent self-employment wage tax on their salary.

Miami Tax partner Michael Kosnitzky is “fairly certain” that President Trump is using this strategy and says it almost certainly gives the president a multimillion-dollar tax benefit by helping him avoid the 3.8 percent tax that was created by the 2010 Affordable Care Act.

“He takes a reasonable salary,” Kosnitzky explained to the publication. “The remaining profits are paid out as an S corp. dividend without the imposition of either the net investment income tax or Medicare tax, so he saves 3.8 percent on this income.”

Read the full Bloomberg Businessweek article here.