The Atlantic Philanthropies focused its giving on health, social, and politically left-leaning public policy causes in Australia, Bermuda, Ireland, South Africa, the United States and Vietnam.

[5][6] With the single largest advocacy grant ever made by a foundation, the Atlantic Philanthropies committed $27 million to win passage of the Affordable Care Act in the United States.

[3] The Atlantic Philanthropies commenced a spend-down process in 2012, and planned to fully close down by 2020 after the remaining portion of Feeney's fortune was donated.

[2][7][8] On September 14, 2020, Feeney signed the documents to officially close the nonprofit in an online ceremony that included a congratulatory video message from Bill Gates.

The Atlantic Philanthropies was a limited-life foundation (following plans for a spend-down put forward in 2002),[15] which stated it would close its doors upon the successful completion of its task of giving away to charity all of founder Chuck Feeney's fortune (except for $2 million he had set aside decades earlier for the retirement of himself and his wife).

In 2020, Feeney announced that the foundation had successfully achieved its purpose, and on September 14, 2020, he signed the documents to officially close the nonprofit in an online ceremony.

[30][31] In March 2009, AP pledged $125 million to the University of California, San Francisco to fund a medical center at the Mission Bay campus.

[36] From 1997 to 2013, AP donated $381.5 million towards health and educational causes in Vietnam, including funds to modernize the country’s public and primary health systems, promote healthier behavior (including backing a country-wide anti-smoking campaign and an initiative that resulted in a national law mandating helmet use by motorcycle riders) and revitalize libraries and universities.

[38] The Atlantic Philanthropies awarded UC San Francisco and Trinity College Dublin $177 million to create the Global Brain Health Institute, a groundbreaking venture to stem the precipitous rise in dementia by training and connecting a new generation of leaders worldwide.