About
Dr. Jonathan Siu is a board-certified family medicine and sports medicine physician based in Upland, CA. He earned his BS in Bioengineering from UCLA before completing his Doctor of Osteopathic Medicine at Touro University. He then trained in Family Medicine at Kaiser Permanente Fontana, where he also completed a Sports Medicine Fellowship in 2018.
After his fellowship, Dr. Siu spent four years at Kaiser Permanente Indian Hill and three years at San Bernardino Public Health. He founded Forte Health to build a practice centered on proactive care and real doctor-patient relationships. His clinical passions include preventive medicine, metabolic health, musculoskeletal care, and empowering patients through education and informed decision-making. Outside the office, he travels on points, plays badminton, and spends time with his wife and son. He exercises regularly and believes in leading by example, both in life and in medicine.
Education & Training
Undergraduate
University of California, Los Angeles, BS Bioengineering (2006-2010)
Medical School
Touro University, DO, Doctor of Osteopathic Medicine (2010-2014)
Residency
Family Medicine, Kaiser Permanente Fontana (2014-2017)
Fellowship
Sports Medicine, Kaiser Permanente Fontana (2017-2018)
Certifications
Conditions Treated
Who is Dr. Siu right for?
Dr. Siu suits patients ages 3 and up who want a consistent, relationship-driven primary care physician. Adults managing chronic conditions like diabetes, hypertension, thyroid disorders, or cardiovascular disease benefit from his preventive focus. Patients with musculoskeletal injuries or athletic health goals fit well with his sports medicine training. He also works well with busy professionals and parents who need same-day access and direct communication with their doctor.
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Frequently Asked Questions
Dr. Siu treats a broad range of conditions across family medicine and sports medicine. These include diabetes, hypertension, chronic kidney disease, cardiovascular disease, thyroid conditions, menopause, low testosterone, musculoskeletal injuries, gastrointestinal problems, and weight management concerns. He also handles acute and urgent care needs for patients ages 3 and up.
Yes. Dr. Siu holds board certification in both Family Medicine and Sports Medicine. He completed his Family Medicine residency at Kaiser Permanente Fontana and followed that with a Sports Medicine Fellowship at the same institution.
Dr. Siu earned his undergraduate degree in Bioengineering at UCLA and his DO from Touro University. He completed his Family Medicine residency and Sports Medicine fellowship at Kaiser Permanente Fontana. Before founding Forte Health, he practiced at Kaiser Permanente Indian Hill and San Bernardino Public Health.
Dr. Siu focuses on empowering patients through education and preventive strategies. He spends extended time with each patient to understand their health goals and build a personalized plan. His clinical philosophy centers on evidence-based medicine delivered within a genuine doctor-patient relationship.
Yes. Dr. Siu sees patients starting at age 3. He provides annual exams, school and sports physicals, acute care, and preventive care for pediatric patients. Minors must have an accompanying adult membership for a parent or guardian age 19 or older.
Yes. Sports medicine is one of Dr. Siu's two board certifications. He evaluates and manages musculoskeletal conditions and sports-related injuries. Services include joint injections, dry needling, exercise counseling, and sports physicals.
Dr. Siu spent over a decade in both private and public health primary care settings. He practiced at Kaiser Permanente Indian Hill from 2018 to 2022 and at San Bernardino Public Health from 2022 to 2025. He founded Forte Health to practice medicine on his own terms, with a focus on proactive, relationship-driven care.
No. Forte Health does not prescribe chronic benzodiazepines, opioids, or ADHD medications. For patients who need those treatments, Dr. Siu facilitates referrals to the appropriate specialists.
Doctor profile last updated April 11, 2026