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

David Alan Diaz, MD

Individual provider Family Medicine Physician · NPI 1033106380

David Alan Diaz, MD is registered under Family Practice in Round Rock, Texas. Graduated from University of Texas Southwestern Medical School at Dallas in 1990, 36 years ago. Practices with Great Oaks Family Practice PA, a 2-clinician group and accepts Medicare assignment. Licensed in Texas.

Years since qualifying
36
Trained at
University of Texas Southwestern Medical School at Dallas
Licensed in
TX
In the registry since
2005
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

15930 S Great Oaks Dr A-200
Round Rock, TX 78681-5526
Phone: (512) 246-3338
Fax: (512) 246-3368
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence J1080 (TX)

Record details

NPI number1033106380
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedOctober 3, 2005
Last updated in NPPESJuly 13, 2026

Medicare enrollment

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

Medicare specialtyFAMILY PRACTICE
Medical schoolUNIVERSITY OF TEXAS SOUTHWESTERN MEDICAL SCHOOL AT DALLAS
Graduated 1990 (36 years in practice)
Group practice Great Oaks Family Practice Pa — 2 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 patients166
Services billed 382 a service is one billed item, such as a visit, a test or a procedure
Average patient age71

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 $172 8 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.

  • Round Rock Medical Center Hospital · Round Rock, TX

Colleagues at Great Oaks Family Practice PA

Clinicians the CMS Doctors & Clinicians file lists under the same group practice.

Other providers in Round Rock