Ralph A. Defronzo, MD
Endocrinology, Diabetes & Metabolism Physician · San Antonio, TX
Ralph A. Defronzo, MD is an endocrinology, diabetes & metabolism physician with a practice address in San Antonio, Texas, and NPI 1851408843, issued on Aug 24, 2006. Check the license (Texas H7531, as entered in NPPES) on the Texas Medical Board; the Medicare figures below come from public CMS files.
- Name
- Ralph A. Defronzo
- Credential
- MD
- Primary taxonomy
- Endocrinology, Diabetes & Metabolism Physician 207RE0101X
- License number
- H7531 TX
Self-reported in NPPES; status is on the state search - Practice location
- 701 S Zarzamora St, San Antonio, TX 78207
- Phone
- (210) 358-7500
- Enumerated
- Aug 24, 2006
- Record last updated
- May 2, 2011 (not updated in 15 years: call before relying on the address or phone)
- Fax
- (210) 358-7515
- Medicaid ID
- 041218102 TX
- Entity
- Type 1 · individual
8 nearest endocrinology, diabetes & metabolism physician records → All 743 in Texas → Look up another NPI →
Also registered at 701 S Zarzamora St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Ralph A. Defronzo in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersTexas Medical Board
Search for license H7531Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Industry payments in 2024: $142,981.44
71 payments; by number, the most common kind was food and beverage; the largest payer was Corcept Therapeutics. The 5,661 providers of this specialty with any payment received $5,742.15 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Ralph A. Defronzo among 743 endocrinology, diabetes & metabolism physician records in Texas
Ralph A. Defronzo, MD is one of 743 endocrinology, diabetes & metabolism physician records with a practice address in Texas. 87% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 6% of them.
- NPI issued2006 · 6% of these records are older, 61% newer
- In a Medicare fileYes · 87% of these records are
- In the CMS Doctors and Clinicians fileNo · 75% of these records are
- Record last updated2011 · 50% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RE0101X and a Texas practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Endocrinology, Diabetes & Metabolism Physician providers in Texas
There are 743 endocrinology, diabetes & metabolism physician records in Texas.
All 743 in Texas → Every provider in San Antonio → Endocrinology, Diabetes & Metabolism Physician nationwide →
The 8 endocrinology, diabetes & metabolism physician records with the nearest ZIP codes
- Rafeeq Ali, MDSan Antonio, TX 782071902086952
- Damilola Ashorobi, M.DSan Antonio, TX 782071154854552
- Renata Belfort De Aguiar, M.D.San Antonio, TX 782071083889695
- Eugenio Cersosimo, MDSan Antonio, TX 782071396756409
- Alberto Chavez Velazquez, MDSan Antonio, TX 782071679865414
- Vidhya Illuri, MDSan Antonio, TX 782071538480926
- Kathy Lacivita, MDSan Antonio, TX 782071083721153
- Dina Rivera, MDSan Antonio, TX 782071932384807
Common questions
What is Ralph A. Defronzo, MD's NPI number?
Ralph A. Defronzo, MD's National Provider Identifier (NPI) is 1851408843, issued on Aug 24, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Ralph A. Defronzo, MD located?
The NPPES record lists a practice address at 701 S Zarzamora St, San Antonio, TX, 78207. Phone: (210) 358-7500. Providers update this record themselves, so call before visiting.
How can I verify Ralph A. Defronzo, MD's license?
NPPES lists Texas license number H7531, as entered by the provider. Search the Texas Medical Board at https://profile.tmb.state.tx.us/Search.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.