Cobi Blumenfeld-Gantz

Cobi Blumenfeld-Gantz is the CEO and co-founder of Chapter, an AI-powered Medicare navigation platform he started in 2020 after watching his own parents struggle to enroll. Built with co-founder Vivek Ramaswamy and early backing from J.D. Vance, Chapter crossed $100 million in annual recurring revenue and raised a $100 million Series E in April 2026 at a roughly $3 billion valuation. A former Palantir government-team lead with degrees from Wharton and Cambridge, he calls himself one of the most hated people in the Medicare brokerage business precisely because Chapter's advisors are paid to recommend the best plan rather than the most lucrative one.