Microsoft founder Bill Gates has retained his title as wealthiest American, while three founders of online companies joined the top 10.
In the list released on Tuesday, Gates held onto the No.1 spot in the annual list of the 400 wealthiest Americans for the 22nd straight year, with net worth of $US76 billion ($A109 billion), down $US5 billion from 2014,Accordind to Fobers news
Warren Buffett, the head of conglomerate Berkshire Hathaway, ranked second with $US62 billion, while former Oracle chief executive Larry Ellison is third with $US47.5 billion.
Entering the top 10 this year were three founders of e-businesses.
Amazon founder Jeff Bezos bolted from 15th to fourth place at $US47 billion, thanks to the surging value of Amazon stock.
Facebook CEO Mark Zuckerberg, who jumped from 11th to seventh place, had net worth of $US40.3 billion. And Larry Page, CEO of Google, moved from number 13 in 2014 to land the 10th spot, with $US33.3 billion.