The 67-year-old businesswoman moved up one place from last year's ranking after her fortune increased by more than $2 billion. She is among the few Asian Americans in this year's top 10.

Lee owns 60% of SHI International, one of the largest privately held IT providers in the U.S., while her former husband, Leo KoGuan, owns the remaining 40%. The pair paid less than $1 million for a software reseller in 1989 that later became SHI. Forbes ranked SHI 26th on its 2025 list of America's largest private companies.

Technology entrepreneurs dominated Forbes' 2026 list of America's richest self-made women, released earlier this month, accounting for nearly half of the top 10.

The biggest mover in this year's ranking was Daniela Amodei, 38, president and co-founder of Anthropic, who jumped from 28th place to second with an estimated net worth of $15.5 billion. Her fortune soared from $1.2 billion a year earlier following the AI company's latest funding round.

Also in the top 10 were Judy Faulkner, 82, founder and CEO of medical-record software provider Epic Systems, who ranked third with an estimated net worth of $9.6 billion, and Indian-American Jayshree Ullal, 65, CEO of computer networking firm Arista Networks, who placed seventh with a fortune estimated at $6.8 billion.

Thai Lee, founder and CEO of SHI International. Photo from LinkedIn

Born in Bangkok, Thailand, Lee was named after her birthplace. She spent most of her childhood in South Korea before moving to the U.S. as a teenager. After graduating from Amherst College with degrees in biology and economics, Lee worked at South Korea-based Daesung Industrial before returning to the U.S. to pursue an MBA at Harvard Business School, becoming the first Korean woman to graduate from the institution in 1985.

In 1989, Lee and KoGuan acquired a small New Jersey IT company and renamed it Software House International, reflecting their ambitions to build a global technology business.

Over the following decades, SHI grew into a major provider of cloud computing, data center and workplace technology services. The company now serves more than 20,000 customers, including Boeing, Johnson & Johnson and AT&T, operates 35 offices worldwide, employs more than 5,000 people and generates approximately $15 billion in annual revenue.

Lee, who has said Buddhist teachings help her maintain perspective in business, has repeatedly credited SHI's employees for the company's success. "A dollar amount could never accurately convey the respect and admiration I have for the employees of SHI," she told Forbes when discussing her inclusion on the self-made women list a decade ago.