Concierge Medicine
We chose to practice the concierge or personalized care model of medicine so that we are able to act as a dedicated partner with each of our patients. Our philosophy as your physician is to offer you healthcare advice that is tailored to your values, needs and schedule. For you, it means:
- Same day or next business day appointments
- Little or no office waiting; longer appointments when needed
- Direct access to physician, 24/7
- Long distance care
- Care for visiting relatives and/or friends
Meet Dr. David R. Buyer
“I treat the whole patient – both from a physical and psychological standpoint – based on the patient’s health beliefs and motives.”
David R. Buyer
MD, MBA, FACP
Dr. Buyer attended medical school at the University of Illinois and then completed residency and Chief Residency at Rush University Medical Center. After training, he joined Economou and Associates which subsequently became West Loop University Medicine, Ltd. He co-managed that practice until 2011 when David R. Buyer, MD SC was opened.
He has served as Medical Director, Physician Services, Primary Care at Rush University and has served on the Medical Staff Executive Committee and Clinical Information & Technology Committee. He has also co-chaired the Chest Pain pathway committee, been on the Medical Staff by-laws committee and currently serves on the Pharmacy and Therapeutics committee. He was also a member of the Ambulatory Workgroup and Privacy and Compliance Panel for the Certification Commission on Healthcare Information Technology.
Meet Dr. Marina Kovačević
“My patient care philosophy focuses around partnership and individualized care plan.”
Marina Kovačević
MD, FACP, Board-Certified Internal Medicine Physician
Dr. Marina Kovačević is a board-certified Internal Medicine physician with more than a decade of clinical and academic experience. She completed her Internal Medicine residency at Weiss Memorial Hospital and went on to serve as Hospital Medicine Lead at Evanston Hospital within Endeavor Health, where she directed clinical operations and led initiatives focusing on improvements of patient experience, quality of care and interdisciplinary care redesign.
During her tenure, she developed a division-wide Point-of-Care Ultrasound (POCUS) program supported by philanthropy funding, focusing on implementation of bedside ultrasound in patient assessment, skill she happily brings to Quintessential Care. She also presented nationally on innovation in patient-centered care and patient experience. Dr. Kovačević serves as Clinical Assistant Professor at the University of Chicago Pritzker School of Medicine, where she has taught and mentored residents and medical students. Her contributions to education and clinical excellence were recognized with multiple Teaching Awards, the 2025 Physician Excellence Award, and Hospitalist of the Year honors.
Dr. Kovačević’s transition into concierge medicine reflects a purposeful shift toward a more personalized and relationship-driven model of patient care. She believes exceptional medicine is built on time, trust, and meaningful dialogue. Her approach emphasizes proactive prevention, thoughtful chronic disease management, and steady guidance through periods of illness. She is determined to deliver not only clinical expertise, but also dedicated advocacy and continuity.
Dr. Kovačević is committed to ensuring her patients feel heard, informed, and supported — with care that is accessible, attentive, and aligned with their individual goals and values.
