There are approximately 7,000 rare diseases that in aggregate affect five percent of the worldwide population—some 300 million, nearly equivalent to the population of the United States. With fewer than 10 percent of rare diseases having FDA-approved treatments and a small, dispersed community who can share knowledge and experiences, the rare disease experience is notoriously isolating. While the differences in rare diseases can be vast, the many foundations and increasing number of rare disease-focused companies are finding that their rarity binds them. Philanthropy has been a major driver of change in the rare disease space, creating family and patient networks, stepping in to fill major voids, and supporting therapeutic research and discovery. During this private session, rare disease funders will explore collaborative funding mechanisms and innovative financing models, including impact investing and venture philanthropy, with the potential to accelerate progress in rare disease research and reduce duplication of effort across the philanthropic landscape.