Amazon said on Tuesday that it's partnering with Buffett's Berkshire Hathaway and J.P. Morgan Chase in an ambitious effort to cut health-care costs and improve services for U.S. employees. Analysts at Barclays expect it to be the biggest collaboration of its kind for Buffett's conglomerate.
Buffett has said in the past that he admires Bezos's ability to succeed in multiple disparate businesses, e-commerce and cloud computing, perhaps a vote of confidence for Amazon's fledgling health-care ambitions. Buffett, the world's third-richest person, was surpassed in 2016 by Bezos, who now tops the list.
"I've never seen a guy succeed in two businesses almost simultaneously that are really quite divergent," Buffett told CNBC in May.
Buffett calls Bezos the "most remarkable businessperson" of our time and has said that passing on Amazon was one of his biggest investing regrets.
The announcement with Amazon and J.P. Morgan included plans to form an independent company with a fresh approach to health care using technology and without concerns for turning a profit.
Each company will have an executive to help lead the project. For Berkshire, the representative is Todd Combs, an investment officer, and for Amazon, it's Beth Galetti, a senior vice president.
Amazon isn't the only tech company that Buffett has avoided backing, in favor of industrials insurers and retailers.
With Amazon and Google, Buffett said that he saw something in the companies early on, but that Berkshire "missed it" as an investment. Still, he told CNBC, "if I was forced to buy it or short it, I'd buy it."
"I was too dumb to realize. I did not think [Bezos] could succeed on the scale he has," Buffett has said, adding that he "really underestimated the brilliance of the execution."
— With reporting by CNBC staff