Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.

Gregory S. Arent, MD

Individual provider Hospitalist Physician · NPI 1245314210

Gregory S. Arent, MD practises Internal Medicine in San Rafael, California. Graduated from University of California, San Francisco School of Medicine in 1995, 31 years ago. Practices with Permanente Medical Group Inc, a 10,941-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
31
Trained at
University of California, San Francisco School of Medicine
Licensed in
CA
In the registry since
2006
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

99 Montecillo Rd
San Rafael, CA 94903-3308
Phone: (415) 444-2000
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Hospitalist Physician (primary) Taxonomy 208M00000X · Licence A62131 (CA)

Record details

NPI number1245314210
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedOctober 25, 2006
Last updated in NPPESDecember 13, 2021

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolUNIVERSITY OF CALIFORNIA, SAN FRANCISCO SCHOOL OF MEDICINE
Graduated 1995 (31 years in practice)
Group practice Permanente Medical Group Inc — 10941 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients16
Services billed 35 a service is one billed item, such as a visit, a test or a procedure
Average patient age75

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Permanente Medical Group Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 10941 clinicians in the practice; 12 are shown here.

Other providers in San Rafael