Annual Physicals & Preventive Care
Comprehensive wellness exams tailored to your age, gender, and risk factors — including screenings, vaccinations, and lab work to catch issues before they become problems.
Family Medicine · San Mateo, CA
Your Health Deserves a Doctor Who
Actually Listens
Dr. Dirk R. Diefendorf combines decades of clinical experience with a genuinely personal approach — because preventive care and chronic management work best when you feel like more than a chart number.
Comprehensive Primary Care
Patient-Centered Approach
San Mateo Community
What We Offer
Comprehensive Care for
Comprehensive Care for
Every Stage of Life
From routine check-ups to chronic disease management, Dr. Diefendorf provides the full spectrum of family medicine in a setting where you're treated with respect and attention.
Chronic Disease Management
Expert ongoing care for diabetes, hypertension, asthma, thyroid conditions, and other chronic illnesses — with coordinated plans that keep you stable and thriving.
Acute Illness & Injury
Same-week appointments for infections, sprains, allergies, and other urgent concerns — because you shouldn't have to wait weeks to see a doctor when you're not feeling well.
Pre-Employment & Sports Physicals
Convenient physicals for employment requirements, school sports, and occupational health — completed efficiently so you can get back to your day.
Pediatric & Adult Care
One practice for the whole family — from childhood well-visits and immunizations to adult preventive care and men's and women's health.
Lab Work & Diagnostic Coordination
On-site and coordinated laboratory testing, imaging referrals, and specialist consultations — all managed through a single point of contact.
About Your Doctor
A Physician Built on Trust & Experience
Dr. Dirk R. Diefendorf is a board-certified family medicine physician practicing in San Mateo, California. With a career grounded in comprehensive primary care, he has built a reputation among patients for taking the time to understand each person's unique health history, concerns, and goals.
Family medicine, as Dr. Diefendorf practices it, means caring for patients across their entire lifespan — from newborns to seniors — and coordinating with specialists when complex issues arise. He believes the best outcomes come from a partnership between doctor and patient, not a one-size-fits-all protocol.
Comprehensive, lifelong patient relationships
Preventive care focused on long-term wellness
Collaborative approach with specialists when needed
San Mateo community physician since establishment
The Difference
Why Patients in San Mateo
Why Patients in San Mateo
Choose Dr. Diefendorf
A Doctor Who Knows Your Story
Dr. Diefendorf builds continuity of care by remembering his patients — their histories, their families, their concerns. You won't start from scratch at every visit.
No Rushed Appointments
Time matters in family medicine. Each visit is scheduled with enough breathing room for questions, education, and a thorough examination — not a hurried checkbox exercise.
Convenient Central Location
Located at 101 S San Mateo Dr, easily accessible from throughout the San Mateo area with straightforward parking and a welcoming office environment.
Insurance & Accessibility
Dr. Diefendorf works with a broad range of major insurance plans. Contact the office to confirm coverage for your specific plan before your visit.
Insurance & Scheduling
We Accept Most Major Plans
Quality healthcare should be accessible. Dr. Diefendorf accepts a wide range of commercial insurance plans and is happy to verify your coverage when you call to schedule. Please bring your insurance card to your first visit.
Call to Verify Your Plan
(650) 347-0517
Get in Touch
Schedule Your Visit
Whether you're a new patient looking for a family doctor or an existing patient scheduling a follow-up, we're here to help. Reach out by phone or stop by the office.
Office Address
101 S San Mateo Dr
San Mateo, CA 94401-3819
San Mateo, CA 94401-3819
Phone
(650) 347-0517
Office Hours
Monday – Friday: 9:00 AM – 5:00 PM
Saturday – Sunday: Closed
Saturday – Sunday: Closed
Request an Appointment
Fill out the form below and our office will contact you to confirm your appointment time.
Request Received
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