John W. Cassidy, M.D.

President/CEO

Chief Medical Officer

"Our organization has a very simple mission and that is 'the patients always come first.' This mission and the value system derived from it have been and continue to be the only way to sort my priorities."

Dr. Cassidy received his post-graduate training at Harvard Medical School where he also served as an Assistant Professor at their affiliated teaching hospital. He was the Psychiatrist in Charge and co-founder of the Neuropsychiatry Program at McLean Hospital. He founded and served as Chief Medical Officer of the Neurobehavioral Institute of Houston, founded and directed the Neuropsychiatry Subspecialty Services of Del Oro Rehabilitation Hospital and was the Medical Director of Neurobehavioral Programs at Cypress Creek Hospital in Houston, TX.

Certified by the American Board of Psychiatry and Neurology, he has over two decades of experience treating patients with acquired brain injuries and their associated disabilities.

Dr. Cassidy has spoken internationally and authored a number of papers and books dedicated to improving the understanding and treatment of individuals with acquired brain injury. Dr. Cassidy leads the Senior Management Team and is focused on the company’s commitment to quality medical care and its ongoing mission to provide a continuum of care to historically under served patients and their families in need of specialized healthcare services.

Kathy L. Roberts

Chief Compliance Officer and Executive Vice President

"As a Registered Nurse I have always been committed to quality patient care. Serving as Chief Compliance Officer for Nexus has allowed me to be a part of a patient-centered organization committed to always doing the right thing."

Ms. Roberts serves as the Chief Compliance Officer and Executive Vice President for Nexus Health Systems, overseeing regulatory compliance, HIPAA, and accreditation activities. A Registered Nurse since 1971, she received her MBA in 2001.

With over 30 years of nursing experience, she has 18 years of experience directly related to catastrophic and neurological case management, and 10 years of experience related to start-up and administration of specialty hospital environments.

Previous positions include Catastrophic Case Manager, Home Health Director, and ICU Registered Nurse.  She has spent the past six years involved in Regulatory Affairs, HIPAA, Compliance, Quality, Risk Management and Accreditation.

Ms. Roberts’ certifications include a National Certification in Health Care Compliance (CHC), National Certification in Rehabilitation Nursing (CRRN), and National Certification in Case Management (CCM). She is currently a member of the Health Care Compliance Association, the Association of Rehabilitation Nurses, and the Case Management Society of America.

Mike Rzendzian

Chief Financial Officer

Mr. Rzendzian has extensive experience with financial restructurings and turnarounds, capital raising, and debt financing and compliance. His expertise includes budgeting, metric development, the development of cost savings programs, financial department reorganizations, and the application of fundamental business principles to enhance core operational functions across multiple sites. Additionally, he has experience in federal tax, state tax and GAAP compliance and research, acquisitions and divestitures, self-insurance reserve management, and various investment and banking forums. Mr. Rzendzian is well-versed in Medicare, Medicaid and insurance billing environments.

Mr. Rzendzian’s past work experience includes eighteen years with large, public companies including Horizon Healthcare Corporation, KPMG, Sun Healthcare Group, Inc., and The First National Bank in Albuquerque.

Guido Cubellis

Chief Operating Officer

Mr. Cubellis is Chief Operating Officer for Nexus Health Systems and joined the company in 2009. He has over 20 years experience in progressively responsible roles in healthcare management and earned a Masters in both Business Administration and Healthcare Administration from the University of Pittsburgh.

His expertise was honed with nationwide leaders in post acute care including HealthSouth where he was CEO of a freestanding rehabilitation hospital for four years and Select Care for four years where he was not only the CEO of a acute care medical specialty hospital but also trained new administrators for the corporation. Mr. Cubellis was Regional Vice President of Operations for Kindred Healthcare for six years with responsibilities for multiple facilities in Eastern states. According to Mr. Cubellis, “My work at Nexus is the perfect opportunity to balance facility and corporate functions to build on the success of Nexus and move the company to the next level.”

Mr. Cubellis brings a commitment to building on Nexus’ collegial efforts to support facility personnel through valuing each employee and their contribution. He believes that a strong approach to patient centered care with a quality product results in satisfaction for patients, employees, and referral sources and company profitability.