Schmidt will remain on Alphabet's board. The changes are expected to take effect at the company's next regular board meeting in January 2018.
"Larry, Sergey, Sundar and I all believe that the time is right in Alphabet's evolution for this transition," Schmidt said in a statement. "The Alphabet structure is working well, and Google and the Other Bets are thriving. In recent years, I've been spending a lot of my time on science and technology issues, and philanthropy, and I plan to expand that work."
Alphabet's board expects to appoint a non-executive chairman at its January meeting, the company said. No potential apointees were named.
"Since 2001, Eric has provided us with business and engineering expertise and a clear vision about the future of technology," Larry Page, CEO of Alphabet, said in a statement. "Continuing his 17 years of service to the company, he'll now be helping us as a technical advisor on science and technology issues. I'm incredibly excited about the progress our companies are making, and about the strong leaders who are driving that innovation."
When Schmidt joined Google in 2001, he began serving as CEO. In 2011, Schmidt transitioned to executive chairman of the company, where he also acted as an adviser to co-founders Page and Sergey Brin.