Executive Leadership Team

Nick Stavros is the CEO of Community Medical Services, where he has worked for the past 10 years. Previously, Nick was an intelligence analyst and Arabic linguist in the U.S. Army and finished his military career as an Airborne/Ranger-qualified Infantry Captain and Iraq War veteran. Upon honorably discharging from the Army, Nick received his MBA from the UCLA Anderson School of Management and is an alumnus of the Arizona Valley Leadership Institute. Nick is on the board of the National Association for Behavioral Health (NABH) and chairs its Medication Sub-committee. He is also the Arizona representative to the American Association of the Treatment of Opioid Dependence (AATOD) and the president of the Arizona Chapter of AATOD, which provides collaborative opportunities for facilities throughout the state. Nick is also on the ASU Medical Advisory Board, AZ Parent’s Commission on Drug Education & Prevention with the AZ Governor’s office, an Advisory Board Member of the National Conference on Addiction Disorders and a board member for HMP’s Treatment Center Investment & Valuation Retreat (East & West).

Laura Contreras joined CMS in February 2024 as the company’s Chief Financial Officer. Laura has worked for over 30 years in senior financial management; working with both Private Equity and Entrepreneurs in a variety of industries. Laura has had several engagements in Healthcare related industries, including 2+ years in Laboratory Services and 1+ year in Urgent Care clinics. During her career, Laura has overseen the growth and expansion of many PE backed companies. Laura holds an undergraduate degree in Accounting from Colorado State University Denver.

Chris joined CMS in January 2024 as Chief Operating Officer. He has been a leader in the operations industry for over 15 years and prides himself on his ability to develop successful management teams and improve processes. Chris focuses on personal development, improving underperforming service operations, and boosting employee engagement. He attended Texas Tech University where he got his master’s degree in Business Administration and his bachelor’s degree in Restaurant and Hospitality Management. In his free time, Chris loves to spend time with his wife, kids, and their schnauzer, Opie.

Dr. Robert Sherrick was appointed as CMS’s first Chief Science Officer in 2023, transitioning from Chief Medical Officer, a role he served for 6 years. Prior to serving CMS he had experience working at an inpatient addiction treatment facility in Montana, Pathways Treatment Center, treating all forms of Substance Use Disorders and dual diagnosis patients. Dr. Sherrick has been providing Medication Assisted Treatment for Opioid Use Disorder since 2003, initially in an office setting using buprenorphine and subsequently with methadone in Opioid Treatment Programs. He established a state-wide buprenorphine treatment program for VA Montana with an extensive focus on telemedicine. He is board certified in Addiction Medicine through the American Board of Preventative Medicine and is the Immediate Past President of the Northwest Chapter of the American Society of Addiction Medicine. Dr. Sherrick received his MS and BS degrees in Electrical Engineering from the Massachusetts Institute of Technology, and his MD from George Washington University Medical Center.

Stacie Baird has been with CMS since 2022 as Chief People Officer, overseeing the Employee Experience Team (EXT) leading change across a highly distributed workforce with a strong purpose to impact the lives of patients and solve this public health crisis. Driven by purpose and focused on building foundational trust, Stacie has found her way through multiple successful start-ups, high-growth environments, and large public company environments. Specializing in leading innovative HR teams that are highly aligned to having a measurable business impact, she is passionate about the movement from HR to the next generation of HX, or a focus on Human Experience. EXT is the problem-solving team that focuses on the HX of candidates, employees, and partnerships. This team works across the business to focus on the very real human challenges employees navigate each day and look for human centric solutions elevate that experience. Stacie has a BS in Chemistry with a focus in Pharmacology from Butler University.

Michael was appointed as the company’s first Chief Technology Officer in March 2022, leading the information technology team and external vendor relationships. He is responsible for Applications development and support, Data analytics and data integrations, Cybersecurity risk management, IT Infrastructure management and IT Service Desk support for all CMS employees and contractors. During March 2023, Michael also took leadership of the CMS Facilities Maintenance Support Team providing coordination of maintenance & repair vendors, suppliers, and the opening of new clinics. Michael holds a BS degree in Aeronautical Engineering from Rensselaer Polytechnic Institute, and a Master of Engineering degree in Aerospace Engineering from the University of Michigan, starting his career in research and engineering then transitioning to serve as an officer in the United States Air Force. Following his service, he led teams providing Information Technology Risk Management and Cybersecurity services with Ernst & Young LLC. He has held multiple CIO executive leadership positions within the Behavioral Health services industry, providing innovative and cost-effective applications to offer the most effective behavioral health treatment services and outcomes to patients.

Jenn Mason is a seasoned healthcare leader with over 20 years of experience in the MAT/MOUD space. Jenn joined CMS in 2015 and has served in several roles during her tenure, and was promoted in 2022 to her current role of Executive Vice President where she oversees all clinical operations currently serving 20,000 patients in 65 clinics that span 10 states. Her leadership has been instrumental in the growth strategy that has transformed CMS into a leader in the MAT space, deploying strategic and tactical operations for the first 24/7 OTP, which CMS has replicated across the country into the opioid treatment on-demand model. She also played a significant role in executing several acquisitions which led to additional expansion into new markets. Jenn has been a nurse for over 20. Years and holds a degree in Business with an emphasis on Organizational Leadership from Southern New Hampshire University.

Dr. Hillary Tamar is the Medical Director of CMS’s Eastern Territory, and oversees the delivery of gold standard, evidence-based medical care in Ohio, Texas, Indiana, Michigan, Wisconsin and Minnesota. Along with Dr. Stavros and Dr. Sherrick, she serves on CMS’s Medical Advisory Board. She started with CMS in 2021 and entered her current role in 2023. Alongside her administrative duties, Dr. Tamar loves providing direct patient care at multiple CMS clinics. She completed a fellowship in Addiction Medicine at Swedish Medical Center, in Seattle, WA, and is board certified in both Family Medicine and Addiction Medicine. Prior to her post-graduate medical training, Dr. Tamar received her B.S. in Biomedical Science from Marquette University and her M.D. from Chicago Medical School. Dr. Tamar is a passionate presenter and has special interests in both medical education and the treatment of pregnant patients with substance use disorders. Before her time with CMS, Dr. Tamar was a presenter on the American Family Physician (AFP) podcast.

Dr. Mark Stavros serves as the Medical Director for the Western Territory of CMS. He along with Dr. Sherrick and Dr. Tamar serve on CMS’s Medical Advisory Board. He is board certified in both Emergency and Addiction Medicine. Dr. Stavros was awarded the Air Force Health Professions Scholarship and received his Medical Degree at Creighton University. He completed his residency in Emergency Medicine at St. Vincent’s Emergency Medicine Residency Program in Ohio. He has worked as an emergency physician in the panhandle of Florida for the past 26 years and served as the Emergency Department medical director for West Florida Hospital and its associated free-standing Emergency Departments for the past 9 years. Dr. Stavros is an associate clinical professor at Florida State University College of Medicine. He serves as both Education and Clerkship Director of Emergency Medicine for Florida State University.

He is medical director of Gulf Coast Addiction Medicine in Florida focused on the treatment of patients in the community and in jail dealing with addiction. Dr. Stavros has practiced addiction medicine for 12 years and has served as CMO for Maric Healthcare serving patients struggling with addiction. He is a peer mentor for the State of Florida charged with educating recovery programs on the use of medication assisted treatment in addiction medicine.