Many of America’s top philanthropists are probably familiar names to most people because some of them also happen to be the wealthiest billionaires in the United States. Icons such as Bill Gates, Warren Buffet and Mark Zuckerberg are not only famous for their wealth and their phenomenal companies, but they’re also top-notch when it comes to helping those in need. In fact, 40 of the highest givers are in the top 400 list of wealthiest Americans. This might come as a surprise to people who view rich people as misers or “Scrooges.”

For the fourth year in a row, according to Forbes, Warren Buffett is number one in total donations given in a single year. In 2017, he gave a total of $2.8 billion. Of this enormous contribution, $2 billion was given to the Bill and Melinda Gates Foundation. The rest was split between his own foundation, which was named after his late wife Susan Thompson Buffett, and three foundations that were established by his children.

In second place are Bill and Melinda Gates. They gave $2.5 billion in 2017 to a number of charities. The biggest donations went to the Global Fund to Fight AIDS, Malaria and Tuberculosis, the Alliance for a Green Revolution in Africa and the Gates Medical Research Institute. Bill and Melinda have donated over $35 billion through their foundation since 1994. The Bill and Melinda Gates Foundation is now the largest charitable organization in the world.

Third on the list is Michael Bloomberg who is famous for his influential financial information company. He also happens to be a former mayor of New York City. He gave over $702 million in charitable contributions in 2017 and has donated a total of more than $5.5 billion throughout his career. Some of his donations include efforts to support U.S. mayors, an initiative to reduce worldwide coal usage and other endeavors to support the arts and women’s programs in Africa.

The Walton Family, founders of the enormous Walmart company, are in fourth place for top philanthropists. Sam Walton established his charitable foundation in 1987, which was the 25th year after the Walmart stores were founded. His two children and three grandchildren currently oversee the foundation. The organization contributed $193 million in 2017 toward education and $146 million toward environmental and other local programs in Arkansas.