GME Family Medicine Faculty
Mario Martinez, MD
Program Director
Dr. Mario Martinez is the Program Director for the Kaweah Health Family Medicine Residency Program and Medical Director of the Kaweah Health Tulare Clinic. He is passionate about family medicine and, most importantly, about helping residents grow into confident, compassionate physicians who truly care for their patients and communities.
Dr. Martinez earned his medical degree from the University of Illinois, where he was awarded The Jefferson Award for Public Service in Washington, DC, presented by then Vice President Joe Biden. He completed his family medicine residency at UCSF Fresno. After residency, he chose to remain in academic medicine and joined the UCSF Fresno Family Medicine faculty. He served as Associate Program Director and practiced and trained residents in full spectrum family medicine, including inpatient medicine, outpatient procedures, and obstetrics.
Dr. Martinez later joined Adventist Health, where he served as a regional director for multiple clinics throughout the Central Valley, before accepting the position of Program Director at Kaweah Health. He also serves on the Kaweah Health Medical Executive Team. His experiences in academic medicine, clinical practice, and healthcare leadership have shaped his commitment to training physicians to become future leaders, manage complex care, and serve underserved communities.
As a program director, Dr. Martinez strives to create a residency environment where residents feel supported, challenged, and valued. He believes some of the best teaching happens through everyday patient care, mentorship, and leading by example. His goal is to make Kaweah Health an exceptional training destination for family medicine, not only in the Central Valley or California, but among the leading family medicine training programs in the country. He is proud to work alongside residents and faculty who share a commitment to providing excellent, compassionate care to the Central Valley. He is particularly passionate about caring for marginalized communities, celebrating diversity, and developing the next generation of physician leaders.
Outside of medicine, Dr. Martinez enjoys making fun memories with his family. Originally from the East Bay Area, he is a lifelong fan of Bay Area sports teams, enjoys trips to Disneyland, and is a passionate fan of all things Star Wars.
Ravi Kumar, MD
Preceptor
Dr. Kumar is one of the most experienced clinicians in the Family Medicine Residency program. Over the past 45 years, he has been a committed and enthusiastic teacher for many physicians. He starts each day full of energy, whether participating in didactic sessions, precepting at the Family Medicine Center, or seeing patients at his other practice sites.
When asked about his pet peeves, his response is simple: "Negative thoughts, procrastinators, and lazy bums." Kindness and a spiritual nature are among his defining qualities. He loves medicine and defines himself as "one who seeks finds." An avid lifelong reader, he keeps current with evidence-based medicine practices. His professional goal is "to publish or perish," as he jokingly puts it.
Dr. Kumar's best times are spent relaxing at home with friends and family.
Stephen Zerlang, DO
Core Faculty and Preceptor
Dr. Zerlang was born and raised in Visalia, California. After completing his medical education at Rocky Vista University College of Osteopathic Medicine and residency training at North Colorado Family Medicine in Colorado, he returned to the Central Valley to serve the local community. Prior to joining the residency program as core faculty, Dr. Zerlang worked for a federally qualified health center. He considers it a privilege to work alongside resident physicians and appreciates being challenged by their perspectives and insights. He sees his role in training residents as a practical means to multiply his impact on the well-being of the local community.
Dr. Zerlang enjoys broad-spectrum family medicine and practices in both inpatient and outpatient clinical settings. His time is divided between inpatient/hospitalist medicine, clinical precepting, and solo clinical practice. His particular interests include obstetrics and maternity care, community outreach, and procedural training.
Outside of work, he enjoys spending time with his wife and children. He loves adventuring in the mountains and relaxing at the coast. His hobbies include mountain biking and water skiing.
Yesenia Calderon, MD
Core Faculty and Preceptor
Dr. Yesenia Calderon Leon was born in Guanajuato, Mexico and she immigrated with her family later in her childhood and grew up in the Central Valley. She is a proud daughter of farmworkers and is proud to continue serving the community where she grew up. She completed her medical education at Charles R. Drew Medical Education Program/David Geffen School of Medicine at UCLA and residency training at Kaweah Health Family Medicine in Visalia, California. Upon graduation in 2025, she joined the program as core faculty.
Dr. Calderon Leon values the opportunity to mentor residents and medical students, and she is committed to fostering a supportive and collaborative learning environment. She sees her role as a physician and educator as a way to give back to the community while inspiring the next generation of family medicine physicians. Dr. Calderon Leon practices full-spectrum family medicine, balancing inpatient and outpatient clinical care. Her professional interests include women’s health, community outreach, and mentoring underrepresented students in medicine. She is passionate about advancing health equity and providing high-quality care to underserved populations in the Central Valley.
Outside of medicine, Dr. Calderon Leon enjoys spending quality time with her family and friends. She loves exploring local food spots and watching movies.
Catherine Whitlach, MD
Faculty
Brandy Truong, MD
Faculty
