Amount donated in 2013: $992.2-million
Beneficiary: Silicon Valley Community Foundation
Background: Mr. Zuckerberg is co-founder and chief executive of Facebook. Ms. Chan is a pediatrician.
The couple gave 18 million shares of Facebook, valued at about $992.2-million, to the Silicon Valley Community Foundation, in Mountain View, Calif. They donated the same number of shares in Facebook to the fund in 2012.
In 2010, Mr. Zuckerberg, now 29, pledged $100-million to establish Startup: Education, a foundation to support programs to improve public schools in Newark, N.J. He is a board member of Startup: Education.
Mr. Zuckerberg did not say what programs the latest gift would support but said that their philanthropy would focus on children.
The Philanthropy 50: Browse the full list of America's most generous donors in 2013.