Theresa Thanh Ngoc Nguyen, M.D.
Internal Medicine · Santa Ana, CA
At a glance
5030 Westminster Ave, Santa Ana, CA 92703-1151
NPPES record updated Jul 20, 2026. Public records can lag behind changes at a practice.
Before you call: a quick checklist
- Are you accepting new patients?
- Do you accept my specific insurance plan?
- Do you provide the service I need at this address?
- Do I need a referral, and what is the earliest appointment?
Insurance participation and appointment availability are not established by these public records.
Medicare & insurance
Insurance participation is not established by these public records. Ask the practice and your insurer about your specific plan and this location.
How to check your coverage
Use your plan’s provider directory or the member-services number on your insurance card. Confirm the clinician, practice address, service, and whether a referral is required. A missing opt-out record does not establish Medicare acceptance.
Check the official Medicare directory ↗Practice location
5030 Westminster AveSanta Ana, CA 92703-1151
Education & affiliations
- Medical / professional school
- University Of California, San Diego School Of Medicine
- Graduation year
- 1995
- CMS specialties
- Internal Medicine
Practice groups
Graduation year does not establish years in practice. A reported affiliation does not establish employment, current admitting privileges, or insurance participation.
Source: CMS National Downloadable File · Published Oct 15, 2026.
Procedures in the public data
Reported activity can help you ask more informed questions about a practice’s services.
No displayed procedure-category record in this release. This does not mean the clinician performs no procedures.
CMS uses a one-year claims window with a reporting lag. Counts cover the Medicare activity included by CMS, not all patients. “1–10” is a published range. Volume is not a quality or outcomes score. Coverage and methodology
Source: CMS Utilization Data · Published Oct 15, 2026.
Find providers with a similar service mix
Compare 2024 published Medicare activity in the same reported specialty, here or in another city.
Industry-reported general payments
Includes reported transfers of value, such as meals, travel, or consulting. Payments do not establish improper conduct or quality of care. Research funding and ownership values are excluded from this total.
See payment purposes and reporting companies
Reported purposes
| Purpose | Amount |
|---|---|
| Food and beverage | $1,665.86 |
Reporting companies
| Company | Amount |
|---|---|
| MAYNE PHARMA COMMERCIAL LLC | $246.07 |
| ASTRAZENECA PHARMACEUTICALS LP | $244.08 |
| GILEAD SCIENCES, INC. | $226.22 |
| AMGEN INC. | $186.61 |
| ARDELYX, INC. | $181.06 |
| SUMITOMO PHARMA AMERICA, INC. | $95.65 |
| ABBVIE INC. | $83.57 |
| LUNDBECK LLC | $61.84 |
| Other reporting companies | $340.76 |
Source: CMS 2025 payments grouped by covered recipient and nature of payments · Published Jun 30, 2026.
Professional details: NPI, taxonomy & registry record
Registry details
- Primary taxonomy
- Internal Medicine
- Taxonomy code
- 207R00000X
- Enumeration date
- Dec 22, 2005
- Record updated
- Jul 20, 2026
More registry details
- Provider type
- Individual · Type 1
- Other reported name
- THANH NGOC NGUYEN
- Reported credentials
- M.D.
Reported taxonomies and licenses
207R00000X · Primary
License reported: A61129 CA
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
5030 Westminster AveSanta Ana, CA 92703-1151
- Phone
- (714) 775-8090
- Fax
- (657) 251-0494
Mailing address
5030 WESTMINSTER AVESANTA ANA, CA 927031151
Information may be outdated or incomplete. Confirm details directly with the practice. HCPList is an independent directory and is not affiliated with CMS.
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