Jon Maack

Mr. Maack is an Operating Partner of Arsenal for the healthcare team. Currently, he also serves as the CEO of OncoHealth, an Arsenal portfolio company. Prior to joining Arsenal in 2025, Mr. Maack was the President of Definitive Healthcare, a leading healthcare commercial data business. Under his leadership, the company executed two strategic acquisitions, adding use-case driven analytics and claims visualization capabilities across its end markets. Previously, he held senior leadership roles as Chief Strategy and Corporate Development Officer at athenahealth and Chief Strategy Officer for OptumInsight. His earlier experience includes serving as a General Manager at the Advisory Board Company and as a Senior Manager at Bain & Company.