Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
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Dr. Tammy Pei-Hsin Cheng Sievers, MD

Individual provider Rheumatology Physician · NPI 1619004694

Dr. Tammy Pei-Hsin Cheng Sievers, MD practises Rheumatology in Ventura, California. Graduated from Washington University School of Medicine in 2002, 24 years ago. Practices with Community Memorial Health System, a 187-clinician group, works from 2 locations, accepts Medicare assignment and offers telehealth. Licensed in California.

Years since qualifying
24
Trained at
Washington University School 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

120 N Ashwood Ave
Ventura, CA 93003-1810
Phone: (805) 658-5800
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 5855 Olivas Park Dr, Ventura, CA 93003-7672 — (805) 667-2801

Specialties & licences

Rheumatology Physician (primary) Taxonomy 207RR0500X · Licence A110176 (CA)

Record details

NPI number1619004694
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorNo
NPI enumeratedFebruary 27, 2007
Last updated in NPPESMarch 8, 2021
Certification dateMarch 8, 2021

Medicare enrollment

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

Medicare specialtyRHEUMATOLOGY
Medical schoolWASHINGTON UNIVERSITY SCHOOL OF MEDICINE
Graduated 2002 (24 years in practice)
Group practice Community Memorial Health System — 187 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

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 patients294
Services billed 1,051 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.

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 $556 30 payments · 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. Those with a page here are linked.

  • St Johns Regional Medical Center Hospital · Oxnard, CA · listed as St Johns Regional Imaging Center LLC
  • Community Memorial Hospital - Ojai Hospital · Ojai, CA
  • Community Memorial Hospital - Ventura Hospital · Ventura, CA

Colleagues at Community Memorial Health System

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 187 clinicians in the practice; 12 are shown here.

Other providers in Ventura