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

Ralph A Defronzo, MD

Individual provider Endocrinology, Diabetes & Metabolism Physician · NPI 1851408843

Ralph A Defronzo, MD is an Endocrinology, Diabetes & Metabolism Physician in San Antonio, Texas. Licensed in Texas. Registered with an NPI since 2006.

Licensed in
TX
In the registry since
2006
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

701 S Zarzamora St
San Antonio, TX 78207-5209 Not confirmed with CMS for 15 years — call before visiting
Phone: (210) 358-7500
Fax: (210) 358-7515
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Endocrinology, Diabetes & Metabolism Physician (primary) Taxonomy 207RE0101X · Licence H7531 (TX)

Record details

NPI number1851408843
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedAugust 24, 2006
Last updated in NPPESMay 2, 2011

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.

Consulting Fee $58,850 25 payments
Compensation for services other than consulting , including serving as faculty or as a speaker at a venue other than a continuing education program $33,000 6 payments
Travel and Lodging $16,674 20 payments · travel or lodging paid or reimbursed, such as to attend a conference
Honoraria $3,120 2 payments
Food and Beverage $935 9 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.

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