Angel Magar, MBA

Angel Magar, M.B.A.

Chief Executive Officer

Angel and her husband Jason relocated from the Washington, D.C. area in early 2007. Angel received both her Bachelors degree in Business and Administration and her Masters in Business Administration from Johns Hopkins University. She brings over 15 years of healthcare management experience from the following specialties: Orthopedics, Radiology, Otolaryngology, Obstetrics and Gynecology, Family Practice, Urgent Care, Occupational Health, and Pediatrics.

Angel’s management experience falls into six broad areas: strategic planning; daily operations of both medical offices and corporate office administrative functions; human resources oversight; marketing implementation and oversight; and daily oversight of information technology.

Matt Peterson

Matthew Peterson, MSIM

Director of IT

Matt has been featured in numerous TV/radio shows and newspaper/magazine articles. He graduated from Brigham Young University in 2000 with a bachelor’s degree in Business Management and from Arizona State University in 2019 with a master’s degree in Information Management and worked six years as the director of information technology at OneGuard and another six years as the chief architect and technology director at Glendale Elementary School District, serving 15,000 underprivileged children. He started a sucessful technology company and created an infrastructure that attracted half a billion website visitors in just the first few months.

Matt wrote a best-selling fantasy novel called Paraworld Zero and was invited to speak throughout the country. He was also the radio show host of where he interviewed world-famous authors such as Dean Koontz, Anne Rice, and R. L. Stine. He served a 2-year mission for his church, earned the Eagle scout award in Boy Scouts, received a second-degree black belt in karate, and performed in several musicals. He lives in Peoria with his wife, seven children, and their giant African tortoise.


Billy Steele, BA Hons (1:1), SHRM-SCP

Chief Operations and Human Resources Officer

Billy joined AARA in 2017, having arrived fresh off the boat from Edinburgh, Scotland. Billy combines a love of the sweltering Phoenix sunshine with a famous distaste for Mexican cuisine and a consistent struggle to be understood as he hasn’t yet lost his accent. Billy graduated top of his class in 2003 and has worked in senior HR roles for 15 years in Healthcare, Government Services, Construction and IT Services. Billy brings experience of all aspects of Human Resources Management, Employment Law and Strategic Management to the Practice. Outside of work, Billy and his wife Moyra enjoy regular trips to Las Vegas, hiking and the theater. Billy’s areas of responsibility include Recruitment and Selection, Onboarding and Training, Performance Management, Management Development, Policy Development and Legal Compliance, Payroll Administration, Event Management and Workforce Planning.


Denise McNulty

Director of Revenue Cycle Management

Denise is a native of Phoenix, AZ and joined AARA in 2019. With 25 years of professional experience in financial operations of hospitals, ambulatory surgery centers and physician group practices across the U.S.A., Denise’s focus is on revenue cycle management. She provides counsel to health care providers on complex regulatory and reimbursement matters. Her experience includes specialty practice management with Orthopedics, Rheumatology, Transplantation, and Pharmacy billing and collections.

Prior to joining AARA, Denise worked for Phoenix Children’s for seven years in the area of transplantation and specialty programs. Her expertise with Medicare, AHCCCS and commercial payers brings her full circle back to when she consulted nationally. Denise’s areas of responsibility include billing, collections and revenue reporting to elevate the patient experience from a financial perspective. Denise enjoys volunteering, music and resides in Scottsdale with her husband and daughter.

Prakash Viswanathan

Prakash Viswanathan

Director of Finance

Renita Klemmedson

Renita Klemmedson

Infusion Director

Christina Schell

Christina Schell

Lab Manager

Missie Hernandez

Missie Hernandez

Radiology Manager


Desiree Belliard, M.A.

Mesa, Site Manager

Deborah Andrews

Deborah Andrews

Paradise Valley, Site Manager

Adrianna Contreras

Adrianna Contreras

Phoenix, Site Manager

Jasmine Hernandez

Sun City, Site Manager

AJ Shendowich

AJ Shendowich

Flagstaff, Site Manager

Hannah Worrall

Patient Service Center Manager

Tatiana Bush

Tatiana Bush

Quality & Risk Manager

Stephanie Leiker

Accounting Manager

Infusion Manager