NPI age
20 years
Enumerated 2005-07-07
● Active
Type 1 · Individual
Santiago Villarreal, M.D.
Villarreal is 1 of 165 internal medicine providers in San Antonio and 1 of 1582 in Texas.
Primary specialty
Internal Medicine
Licensed in
TX
1 state
Status
Active
No deactivations on record
Last NPPES update
2023-10-06
Source: monthly bulk 2026-05
Sole proprietor
Yes
Solo practice on file
How this provider compares
Across 1582 active internal medicine providers in Texas.
NPI age
20 years
↑ 2 yr above median (18 yr)
State licenses
1 state
14% of peers hold multiple states
Subspecialties
0
34% of peers hold subspecialties
NPI lifetime · 2005 → 2026
2005-07Enumerated in NPPES
2005
2026
Where they practice
Practice location
4151 Callaghan Rd, Suite 103
San Antonio, TX 782283419
Mailing address
4151 Callaghan Rd, Suite 103
San Antonio, TX 782283419
Specialties
-
Internal Medicine PrimaryAn internist who treats disorders of the kidney, high blood pressure, fluid and mineral balance and dialysis of body wastes when the kidneys do not function. This specialist consults with surgeons about kidney transplantation.
Practice context
Part of a multi-provider practice. 5 other active providers share this practice address in NPPES.
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- Confirm the NPI on NPPES.The CMS registry is the system of record. Open NPPES →
- Check the state license is currently active.State licensing boards publish current status; NPPES does not.
- Confirm payer enrollment if billing.NPI presence does not guarantee active enrollment with Medicare, Medicaid, or commercial payers.