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

Jonathan Lo, MD

Individual provider Internal Medicine Physician · NPI 1164570941

Jonathan Lo, MD is a Hospitalist in Fontana, California. Graduated from Un of California, Irvine, College of Medicine in 1997, 29 years ago. Practices with Southern California Permanente Medical Group, an 11,242-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
29
Trained at
Un of California, Irvine, College of Medicine
Licensed in
CA
In the registry since
2007
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

9961 Sierra Ave
Fontana, CA 92335-6720
Phone: (909) 427-3910
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence A66923 (CA)

Record details

NPI number1164570941
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJanuary 8, 2007
Last updated in NPPESDecember 2, 2021

Medicare enrollment

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

Medicare specialtyHOSPITALIST
Also practisesINTERNAL MEDICINE
Medical schoolUN OF CALIFORNIA, IRVINE, COLLEGE OF MEDICINE
Graduated 1997 (29 years in practice)
Group practice Southern California Permanente Medical Group — 11242 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 patients15
Services billed 41 a service is one billed item, such as a visit, a test or a procedure
Average patient age74

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.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $141 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Southern California Permanente Medical Group

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 11242 clinicians in the practice; 12 are shown here.

Other providers in Fontana