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

Mr. Tarquin Siam Williams, PA-C

Individual provider Medical Physician Assistant · NPI 1750539391

Mr. Tarquin Siam Williams, PA-C is a Physician Assistant in Cathedral City, California. Qualified in 2007, 19 years ago. Practices with Southern California Permanente Medical Group, an 11,242-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
19
Licensed in
CA
In the registry since
2008
Specialties on file
2
What do these letters mean?
PA-C — Physician Assistant, Certified
A physician assistant who holds current national certification.

See every abbreviation used in this directory →

Practice location Address checks out

69175 Ramon Rd Bldg A
Cathedral City, CA 92234-3344
Phone: (760) 321-6776
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Physician Assistant (primary) Taxonomy 363A00000X · Licence PA19872 (CA)
Medical Physician Assistant Taxonomy 363AM0700X · Licence PA19872 (CA)

Record details

NPI number1750539391
Entity typeIndividual (Type 1)
GenderMale
Credentials PA-C
Sole proprietorYes
NPI enumeratedSeptember 8, 2008
Last updated in NPPESSeptember 26, 2023
Certification dateApril 26, 2021

Medicare enrollment

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

Medicare specialtyPHYSICIAN ASSISTANT
Medical schoolOTHER
Graduated 2007 (19 years in practice)
Group practice Southern California Permanente Medical Group — 11242 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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 patients12
Services billed 12 a service is one billed item, such as a visit, a test or a procedure
Average patient age68

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.

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 Cathedral City