Mark Zimmer
- Director of Finance, National Kidney Registry
Mark Zimmer is the Director of Finance for the National Kidney Registry and is responsible for financial planning, reporting and cash management for the organization.
Prior to joining the NKR in 2021, Mr. Zimmer spent 14 years with Brown Brothers Harriman as Vice President & Controller for the administrative divisions, where he oversaw budgeting, forecasting and planning functions for an organization of over 900 employees and over $200MM in annual expenses. Prior to that, he supported the Investment Management and Private Banking business lines where he led client and product profitability reporting for over $65B in assets spanning 7 BBH offices.
Before his time at BBH, Mr. Zimmer supported the Material Handling Finance and Franchise Finance businesses at Citigroup. He earned his B.S. in business from the University of Connecticut.
Mr. Zimmer lives with his wife and two daughters in Stamford, Connecticut where he enjoys watching his daughters’ soccer games and ballet recitals, working in his vegetable garden, and brewing IPA. He also enjoys camping, hiking, and is an avid skier.

Our Leadership
- Garet HilFounder and Chief Executive Officer
- Matthew Cooper, MDSurgical Director
- David Serur, MDMedical Director
- Michael Cecka, PhDLab Director
- Amy Waterman, PhDResearch Director
- Karen Miller, RNChair, Operations Committee
- Michael LolloChief Operating Officer
- Ryan MeehanChief Financial Officer
- Kevin NelsonChief Information Officer
- Joe SinacoreVice President, Network Development
- Samantha HilDirector of Marketing
- Larry McMahonDirector of Operations
- Matthew RoninDirector of Research & Technology
- David ZhelezovManager, Operations
- Timothy Wan, Esq.Corporate Counsel