Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Howard Guan, MD

Individual provider Ophthalmology Physician · NPI 1134427636

Howard Guan, MD is an Ophthalmology in San Marcos, California. Graduated from Loma Linda University School of Medicine in 2010, 16 years ago. Practices with Tory Prestera MD Inc, a 2-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
16
Trained at
Loma Linda University School of Medicine
Licensed in
CA
In the registry since
2011
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

340 Rancheros Drive Suites 164/166
San Marcos, CA 92069
Phone: (760) 598-0400
Fax: (760) 290-7044
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Glaucoma Specialist (Ophthalmology) Physician (primary) Taxonomy 207WX0009X · Licence A119766 (CA)
Ophthalmology Physician Taxonomy 207W00000X · Licence A119766 (CA)

Record details

NPI number1134427636
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedMarch 7, 2011
Last updated in NPPESOctober 21, 2025
Certification dateOctober 21, 2025
Mailing address340 Rancheros Drive, Suites 164/166, San Marcos, CA 92069

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyOPHTHALMOLOGY
Medical schoolLOMA LINDA UNIVERSITY SCHOOL OF MEDICINE
Graduated 2010 (16 years in practice)
Group practice Tory Prestera Md Inc. — 2 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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