Dr. Berkley's Care Team

William Gregory Berkley, M.D.

Dr. Berkley is a native Texan finally returning “Home” after practicing in Georgia for over 25 years. As a double Board Certified Physician in both Internal Medicine and Nuclear Cardiology, he utilizes his extensively thorough training to provide the most comprehensive patient care. Dr. Berkley’s rare combination of board certifications allows him not only to be a highly qualified primary care physician to patients 14 years and older, but also utilize his expertise in finding, treating, and preventing cardiovascular disease. As a local resident, Dr. Berkley brings experience, compassion, dedication, and commitment to the communities of Oak Hill. In his leisure time, he enjoys being a family man, deep-sea fishing, boating, and golf. Dr. Berkley lives by the motto “Dedicated to Caring”.

Care Philosophy

"My care philosophy is based on four core values:

Service: I strive to be available when called upon. I respect patients’ views by listening to what they say. I strive to form a special patient-physician relationship that values patient ideas, philosophy, and comfort level. I make sure to take time to explain the issues in a way that you understand the condition(s) present and discuss all the pros/cons of the treatment choices.

Commitment: I am totally committed to my medical profession. I am dedicated to continuous education, staying current with new treatment options, and not afraid to use the latest approved medical modalities. Most of all, I am committed to “you”, constantly in pursuit of enhancing your total well-being both mentally and physically.

Compassion: Since 7th grade, I have always wanted to be a physician. I feel it is my calling in life. I take all patient complaints and health issues seriously. I believe in building a patient-physician relationship on respect, trust, and honesty. I embrace the challenges of each individual to not just identify a problem but to figure out why it is there and treat it appropriately. Compassion is what drives me.

Team: It’s my philosophy that in order to achieve excellent patient care, teamwork is required. In my mind there is no hierarchy; everyone is an integral part of a successful team, and a successful team creates an environment that will positively impact patient care. Healthcare today is extremely complex and without good team relations the patient loses out. It is an honor and a privilege to practice medicine and I embrace it every day!"

Accepting New Patients: Yes, Including New Medicare, Private Pay and Most Commercial Insurances

Undergraduate: University of Texas
Medical: American University of Caribbean
Residency: Presbyterian University of Pennsylvania
Fellowship Nuclear Cardiology
Emory University Hospital

Board Certifications

Internal Medicine
Nuclear Cardiology


Fellow American College of Physicians
American Society Nuclear Cardiology
American Society Echocardiography
American Society Internal Medicine
Honored Member of Who's Who in Health Sciences

Cathleen Villela, PA-C

Cathleen Burke is a native of Dallas, Texas. She graduated from the University of Texas at Austin with a degree in Psychology and from the University of Texas Medical Branch with a Master's degree in Physician Assistant Studies. Cathleen and her husband, Felipe, live in Austin. She enjoys playing tennis and gardening in her free time and loves to spend time with friends and family, especially if it includes supporting the Texas Longhorns!

Care Philosophy

Cathleen became a physician assistant because of her desire to help others. Being in family practice allows her to work with a diverse patient population since she cares for all ages. She especially likes providing basic preventative care, helping diabetics find the right path for healthy living, and caring for women's health. Seeing all ages of patients with a variety of needs appeals to her ongoing concerns to provide the best possible care to each individual.

Accepting New Patients: Yes

Undergraduate: University of Texas at Austin
Bachelor of Arts in Psychology
Medical: University of Texas Medical Branch at Galveston
Masters of Physician Assistant Studies


Texas Association of Physician Assistants
American Academy of Physician Assistants
Central Texas Physician Assistant Society
Honors and Awards: Interdisciplinary Distinctive Award

Theresa Schmidt, MSN, APRN, FNP-C

Accepting New Patients!

Pronouns: she/her/hers. Theresa is a native Oregonian, but for the last 10 years, she has called Texas her home. Before joining Premier Family Physicians, Theresa worked as a hospital nurse for 14 years in critical care. She earned her Master’s degree in Science of Nursing from the University of Texas at Houston Health Science Center. She lives in Austin with her cat, Toothless. In her free time, Theresa enjoys traveling, trying new foods, and the outdoors.

Care Philosophy

"After spending most of my health career treating chronic conditions at their most severe stages, I have decided to shift my efforts to preventative and primary care. My nursing background allows me to treat each patient as a whole person with unique and individual needs. I view my role as your guide and partner in achieving your health and wellness goals. I will listen to your concerns and make sure that you understand your plan of care."


Undergraduate: Linfield College
Medical: University of Texas at Houston Health Science Center


American Association of Nurse Practitioners
Texas Nurse Practitioners
Austin Advanced Practice Nurses

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