The new pledge signatories come from diverse business backgrounds including technology, real estate and finance, and hail from California, Connecticut, Florida, Michigan, New York and Rhode Island.
"This new group brings extensive business and philanthropic experience that will enrich the conversation about how to make philanthropy as impactful as possible," Bill Gates said in a statement.
The Giving Pledge encourages open conversation about philanthropy and does not involve direct appeals, pooling money or requirements to support a particular cause or organization, according to the statement.
Pledge signatories come together throughout the year to discuss challenges, successes, failures and how to be smarter about giving.
Ranging in age from 28 to 97, they give to a wide variety of causes, including education, health, medical research, social services, the environment and others.