Academic-caliber rheumatology. Private practice access.
On-site biologic infusions. In-office diagnostic ultrasound. Active clinical research. The expertise of a hospital rheumatology program — with a physician who actually knows your name.
Why Synergy Rheumatology
Hospital-level rheumatology services in a physician-owned private practice.
On-Site Infusion Center
RN-administered biologic infusions — infliximab, Cosentyx, Reclast, and more — in a comfortable, monitored setting. No hospital visits, no separate facilities.
In-Office Ultrasound
RhMSUS-certified musculoskeletal ultrasound on a Mindray MX7. Same-day imaging and results — no referral, no waiting weeks.
Clinical Research
Active clinical trials in rheumatology, physician-supervised on-site. Access to emerging therapies before they reach market.
Direct Physician Access
Call, text, or message your rheumatologist through our secure patient portal. No phone trees, no callbacks in 48 hours.
Services
Three specialized service lines, integrated with your rheumatologic care.
Infusion Center
On-site RN-administered biologic infusions including infliximab, Cosentyx, and Reclast. Comfortable, monitored, and coordinated with your treatment plan.
Learn moreDiagnostic Ultrasound
RhMSUS-certified musculoskeletal ultrasound using the Mindray MX7. In-office imaging with same-day results for joints, tendons, and soft tissue.
Learn moreObesity Medicine
Evidence-based weight management integrated with rheumatologic care. Addressing the inflammatory burden of obesity alongside autoimmune disease.
Learn morePurpose-built for rheumatologic care
Our Carlsbad facility was designed specifically for comprehensive rheumatology — from infusion to imaging to consultation.
Infusion Suite
Comfortable recliners, private monitoring, and RN oversight for every infusion.
Ultrasound Room
Dedicated imaging with the Mindray MX7 for same-day diagnostic results.
Consultation Rooms
Private exam rooms designed for thorough evaluation and unhurried discussion.
Your Rheumatologist
Zachary Fellows, MD
Board-Certified Rheumatologist
Board-certified rheumatologist with active clinical research practice, serving on the California Rheumatology Alliance Board of Directors.
- Board-certified in Rheumatology and Internal Medicine
- California Rheumatology Alliance (CRA) Board Member
- UCSD Clinical Integration Network (CIN) affiliated
- RhMSUS-certified musculoskeletal ultrasound
- On-site clinical research principal investigator
What Our Patients Say
Curated from verified Google Reviews.
“Dr. Fellows is the most thorough and knowledgeable rheumatologist I have ever seen. He takes the time to explain everything and genuinely cares about finding the right treatment plan. The infusion center is comfortable and the nursing staff is wonderful.”
J. Brown
“After years of being dismissed by other doctors, Dr. Fellows actually listened and ran the right tests. Diagnosed within two visits. The in-office ultrasound meant I didn't have to wait weeks for imaging results. Highly recommend.”
M. Torres
“The Spruce messaging system is a game-changer. I can reach the doctor directly without sitting on hold. My infliximab infusions are smooth and the RN Jamie is fantastic. This is how medicine should work.”
S. Lawson
“I was referred here for lupus management and could not be happier. Dr. Fellows explains the science behind every decision and the staff makes a stressful diagnosis feel manageable. The whole team is kind and professional.”
R. Chen
“Excellent experience from start to finish. The office is modern, wait times are minimal, and Dr. Fellows is incredibly knowledgeable. He caught something on ultrasound that two other doctors missed. Grateful I found this practice.”
K. Patel
Insurance & Access
We accept all major PPO plans, Tricare, and select HMO plans including Greater Tri-Cities IPA, Sharp Community Medical Group, and UCSD PHSO. Most Medicare Advantage PPO plans accepted.
Ready to get started?
Schedule an appointment or call for an introductory phone consultation to see if Synergy Rheumatology is the right fit.