Rob Marmerstein

Chief executive officer

Robert Marmerstein joined HCA Houston Healthcare Tomball as the Chief Executive Officer (CEO) in July 2020. He will oversee the management and operations of the hospital ensuring both service line and overall strategic goals align with the development of the organization’s vision and strategic plan.

Marmerstein joined HCA Healthcare in 2009. Previously, he served as Chief Operating Officer (COO) of HCA Houston Kingwood for three years and as COO at HCA Houston Mainland for two years. He also served as an administrative resident at Reston Hospital Center in Reston, Virginia and as associate COO at LewisGale Medical Center in Salem, Va.

Marmerstein earned his bachelor of science degree in hospitality management from the University of Central Florida and a master's degree in Health Administration from Virginia Commonwealth University. He is a member of the American College of Healthcare Executives, a board member for the Kingwood Place West Commercial Association, and recently served as a board member of the Greater East Montgomery County Chamber of Commerce.


Mauricio Pinto

Chief medical officer

Mauricio Pinto, MD, SFHM, joined HCA Houston Healthcare Tomball as Chief Medical Officer (CMO) in August 2021. As CMO, Dr. Pinto works with colleagues and physicians to ensure high quality, patient-centered care by leading quality initiatives that support the consistent clinical performance and practice standards across the hospital.

In 2016, Pinto was recruited to Austin, TX to launch a Hospitalist program at St. David’s Round Rock Medical Center, an HCA Healthcare facility, with Team Health. He assisted in the growth of the program into six other sister St. David’s facilities in the Austin area. From 2016 to 2021, Pinto served there in a number of medical directorships, committee chairmanships and staff positions.

A native of Bolivia, Dr. Pinto received his medical degree from Universidad Privada Nuestra Senora de La Paz in La Paz, Bolivia and went on to complete an internship in Internal Medicine at Lenox Hill Hospital in New York, NY. Pinto furthered his education with a residency and fellowship at the Texas Tech University Health Sciences Center. He then began his career as the Hospitalist Medical Director at Medical Center Hospital in Odessa, TX in 2013. Shortly after beginning his hospitalist career in 2013, Pinto led the integration of Procare Hospital Medicine until 2016.

Pinto is Board Certified in Family Medicine and a member of the Society of Hospital Medicine where he received his status as Senior Fellow in Hospital Medicine in 2021.


Adrian Moreno

Chief operating officer

Adrian Moreno joined HCA Houston Healthcare Tomball as Chief Operating Officer (COO) in November 2021. Previously, he served as the Assistant Chief Operating Officer of HCA Houston Healthcare Kingwood.

During his time at HCA Houston Healthcare Kingwood, Moreno led expansion projects at the hospital, including increasing licensed bed capacity by 32 intensive and intermediate care beds. He also managed the expansion project for the hospital’s outpatient surgery center, increasing the number of operating rooms and endoscopy suites. Moreno served as the division director of project management with HCA Houston Healthcare from 2018 to 2020. He was responsible for monitoring the development and implementation of the Division’s top strategic priorities. Before his time at HCA Houston Healthcare, Moreno worked for six years with Ernst and Young, most recently as Performance Improvement Manager.

Moreno is a graduate of the U.S. Military Academy at West Point and U.S. Army Ranger School. He served as an officer in the U.S. Army where he was stationed in Fort Hood, TX and Bagdad, Iraq. He received his Master of Healthcare Administration from Trinity University in 2019. Moreno currently serves as the co-chair of the HCA Gulf Coast Division Veterans Colleague Network and is a member of the HCA Gulf Coast Division Diversity and Inclusion Council.


Richard Ervin

Chief financial officer

Richard Ervin joined HCA Houston Healthcare Tomball as the Chief Financial Officer (CFO) in 2017. With over 24 years of accounting and finance experience, Ervin oversees management of all financial departments, allocation of resources and preparation of the annual budget including accounting and health information. Before joining HCA Healthcare, Ervin began his career with American Medical International in 1986, which later became Tenet Healthcare, where he served as CFO for 10 years then served as CFO for nine years with Community Health Systems in Tomball, Texas.

Ervin earned a bachelor’s of accounting from Stephen F. Austin State University. He currently serves on the board of directors of TOMGWA Health Care Ministries and is a member of Healthcare Financial Management Association.


Maggie Yacoubian, MSN, RN

Chief nursing officer

Maggie Yacoubian joined HCA Houston Healthcare Tomball as the Chief Nursing Officer (CNO) in January 2019. As the CNO, Maggie is responsible for driving, supporting and modeling a culture focused on clinical excellence, employee engagement, quality, patient safety and the overall patient experience.

Yacoubian joined HCA Healthcare in 2012. With over 23 years of nursing experience, she served as the director and administrative director of clinical care and emergency services for Tristar Centennial Medical Center in Nashville, Tennessee for seven years.

Yacoubian earned a bachelor's of science in nursing from South University and a master's of science in nursing leadership and management from Western Governors University. She is a graduate of the HCA Executive Development Program and has been recognized as a Top Ten-High Performer for exceeding top hospital initiatives within HCA Healthcare's emergency room operations.