National Seating & Mobility’s management team, like our company, is geographically diverse, based in cities such as Charlotte, Chattanooga, Indianapolis, Nashville and San Diego.


Photo of William Mixon, CEO / President

William Mixon

Chief Executive Officer

Photo of Bart Witteveen, CFO

Bart Witteveen

Chief Financial Officer

Photo of John Bertone, Sr. VP of Field Operations

John Bertone

Sr. VP Field Operations

Photo of Ann Mahaffey, VP Human Resources

Ann Mahaffey

VP Human Resources

Photo of Charles Sargeant, VP, Southwest & West Regions

Charles Sargeant

Sr. VP Funding Operations

Isaac Rodriguez, VP, Northeast Region

Isaac Rodriguez

VP East Region

Photo of Derek Miller, VP, Central Region

Derek Miller

VP Central Region

Photo of Katie Stevens, VP West Region

Katie Stevens

VP West Region

Photo of Doug McDaniel, VP Business Development

Doug McDaniel

VP Business Development

Photo of Stephanie Buckley, VP Marketing

Stephanie Buckley

VP Marketing

Photo of Kevin Harmon, VP Financial Operations

Kevin Harmon

VP Financial Operations

Photo of Jeff Matukewicz, In-House Counsel

Jeff Matukewicz

General Counsel & Secretary

David Pietrzak, VP Supply Chain & Vendor Management

David Pietrzak

VP Supply Chain & Vendor Management


Ryan Peebles

Director of Government Affairs

Photo of Damaris Robles

Damaris Robles

Director of Operational Excellence

Photo of Karen Shell, Director of Compliance

Karen Shell

Director of Compliance

Photo of Jeremy Stone, VP Payer Relations

Jeremy Stone

VP Payer Relations