Executive Leadership Team

Chief Executive Officer
David T. Vandewater

David T. Vandewater is a distinguished healthcare executive with more than 35 years of healthcare leadership experience. He has focused his career on building value by meeting the needs of healthcare consumers.

Mr. Vandewater began his executive leadership career in healthcare as CEO of Vista Hills Medical Center in El Paso, Texas. In the years since, he has spent time in significant leadership roles while growing some of the healthcare industry’s largest and most successful companies, including Republic Health Corp., USP International, HCA Healthcare and Ardent Health. He spent two decades as President and CEO of Ardent, previously known as Behavioral Healthcare Corp., where he grew revenues from $300 million to $4.4 billion.

Mr. Vandewater is a past chairman of the Federation of American Hospitals (FAH), has served in prominent service roles with the American Hospital Association (AHA), and is a past board member of the Boys and Girls Clubs of Middle Tennessee. He has been recognized by Modern Healthcare as one of the 100 Most Influential People in Healthcare.

A native of El Dorado, Arkansas, Mr. Vandewater holds a Bachelor of Science degree from Henderson State University and a master’s degree in healthcare administration from the University of Houston Clear Lake.

Chief Operating Officer
Brian Walton

Brian Walton joined Summit BHC as Executive Vice President for Operations in September 2025 and was promoted to Chief Operating Officer in December. Prior to joining Summit, Walton was with ScionHealth, where he served as President of the Community Hospital Division. Throughout his nearly 30-year career in healthcare, Walton has also held senior leadership roles at Ardent Health Services, Memorial Hermann Health System and Vanguard Health Systems. At Summit BHC, Walton partners directly with corporate and facility leaders to support operational excellence and ensure the organization continues to deliver high-quality and compassionate behavioral health and addiction treatment.

Chief Financial Officer
Crissy Carlisle

Crissy Carlisle serves as Chief Financial Officer for Summit BHC, bringing extensive leadership experience in financial operations, accounting, and investor relations. Prior to joining Summit, Crissy was the CFO of Enhabit Home Health & Hospice, where she led accounting and financial teams, overseeing month-end close processes, SEC reporting, treasury, risk and insurance, taxes, and internal audit. Before that, she spent 16 years at Encompass Health Corporation as Chief Investor Relations Officer and Vice President of Financial Reporting. She began her career at PricewaterhouseCoopers LLP spending seven years in their audit practice and three years in their corporate recovery practice. Crissy is a Certified Public Accountant and holds an accounting degree from the University of Alabama and a Master of Business Administration from Duke University. Her expertise in financial management and strategic leadership supports Summit’s continued growth and operational excellence. You can watch Crissy Carlisle being interviewed on the podcast “Inspiring Women with Laurie McGraw” here.

Chief Medical Officer
Jeremy S. Musher, MD, DLFAPA

Jeremy S. Musher, MD, has over 30 years of experience in the psychiatric health care industry, and has held senior leadership positions in military, academic, not-for-profit, and for-profit settings. Prior to joining Summit BHC, Dr. Musher served as Chief Behavioral Medical Officer at Lifepoint Health and Chief Medical and Clinical officer for Springstone, a national behavioral health provider before it was acquired by Lifepoint. Prior to this, he provided consultation to healthcare organizations and leaders in a variety of settings through his consulting company, Musher Group, LLC, and provided medical leadership to one of the busiest psychiatric only emergency services in the country at Western Psychiatric Institute and Clinic at the University of Pittsburgh. He previously served as Vice Chairman of the Department of Neuropsychiatry and Behavioral Sciences and Associate Dean for Student Affairs at the University of South Carolina; Chairman of the Department of Psychiatry, Medical Director for the Mercy Center for Chemical Dependency Services, and Vice President of Mercy Hospital for the Pittsburgh Mercy Health System; and Owner and Medical Director for Vista Behavioral Health in Pittsburgh. Dr. Musher also represents the American Psychiatric Association as Advisor to both the AMA CPT Panel and to the AMA RVS Update Committee (RUC). Dr. Musher obtained his medical degree from the University of Maryland and completed his residency in Psychiatry at the National Naval Medical Center in Bethesda, Maryland. He also served as a Lt. Commander in the US Navy.

General Counsel
Steve Hinkle

Steve Hinkle currently serves as General Counsel for Summit BHC and brings more than two decades of experience at the intersection of healthcare compliance, law, and government enforcement. Prior to this, he served as interim Chief Compliance Officer for the organization and Chief Compliance Officer for Ardent Health Services, where he led the development and oversight of comprehensive corporate compliance programs and regulatory initiatives. Earlier in his career, Hinkle held senior legal roles within large healthcare organizations and served as a trial attorney in the U.S. Department of Justice’s Fraud Section, Criminal Division, prosecuting complex financial cases. 

Hinkle also served as a Judge Advocate and armor officer in the United States Marine Corps, retiring as a lieutenant colonel from the Marine Corps Reserves. His extensive background in compliance strategy, regulatory matters, and litigation positions him as a trusted leader dedicated to advancing ethical standards and strengthening organizational integrity across the healthcare landscape.

Chief Human Resources Officer
Tim Stein

Tim Stein serves as Chief Human Resources Officer for Summit BHC, bringing extensive experience in human resources, talent development, organizational effectiveness, and workforce engagement. Throughout his career, he has led initiatives focused on employee development, leadership training, and organizational growth, helping healthcare organizations build strong, mission-driven cultures.

Prior to becoming CHRO, Stein held senior human resources and training leadership roles where he led efforts to strengthen organizational culture, enhance employee engagement, and develop leaders across all levels of the organization. He has played a key role in designing and implementing standardized HR systems, talent development strategies, and workforce initiatives that support growth and operational excellence across multi-site behavioral healthcare organizations. His expertise in organizational transformation and change management has helped create highly engaged teams dedicated to delivering exceptional patient care.

As Chief Human Resources Officer at Summit BHC, Stein is responsible for aligning people strategies with business objectives, fostering a high-performance culture, and enhancing employee engagement and retention to support the organization’s continued growth and success. He is passionate about developing leaders, advancing succession planning, and strengthening organizational effectiveness to support Summit BHC’s mission of helping individuals achieve recovery and improved mental health. Outside of work, he enjoys spending time with his wife, staying active in the gym, and pursuing his passion as a car enthusiast.

Group President, West Division
Selene Hammon, MBA

Selene Quintana Hammon, MBA, serves as Group President, West Division for Summit BHC, bringing more than 20 years of executive leadership experience in behavioral healthcare operations, strategic growth, and service line development. She has been with the organization since 2022 and served as Division Vice President for acute facilities. In her career, she has led inpatient, outpatient, and integrated behavioral health organizations across multiple markets nationwide.

Prior to joining Summit BHC, Selene held multiple executive leadership roles overseeing hospital operations, service line expansion and organizational turnarounds, consistently improving financial, clinical, and regulatory performance. She has consistently been recognized for improving operational outcomes, strengthening compliance, and expanding access to quality behavioral healthcare services.

 At Summit BHC, she provides strategic and operational leadership for facilities across the West Division, with a focus on clinical excellence, employee engagement, and patient care.

Group President, East Division
Jamie Carter

Jamie Carter serves as Group President, East Division for Summit BHC, bringing extensive leadership experience in hospital operations, strategic growth, and operational excellence across multi-state healthcare systems. Known for his collaborative, hands-on leadership style, Jamie has successfully led hospital turnarounds, service line integration initiatives and market growth strategies while fostering patient-centered cultures focused on quality care.

Prior to his current role, Jamie served in senior operational leadership positions overseeing healthcare facilities across multiple states, with experience spanning strategic planning, quality improvement, academic partnerships, and operational integration. He is recognized for developing high-performing leadership teams and driving sustainable organizational growth.

At Summit BHC, Jamie provides strategic and operational leadership for facilities across the East Division, supporting the organization’s mission to improve the lives it touches through high-quality behavioral healthcare services.