At a press conference in San Francisco, they said their ultimate goal was to “cure, prevent or manage all diseases by the end of the century”.
The funds will be distributed by the Chan Zuckerberg Initiative, which they created in December 2015.
Tech leaders are increasingly turning their attention to health.
Earlier in the week, Microsoft said it intended to “solve” cancer by using artificial intelligence tools.
Google’s DeepMind unit is working with the NHS to find a way to use computers to more accurately diagnose diseases.
And IBM and MIT announced a tie-up earlier this week to develop AI-based systems that could help clinicians improve the care of elderly and disabled patients.
Even so, the Chan Zuckerberg plan is marked by its ambition.
STORY BY BBC NEWS