Dr. Ralph A. Defronzo
- Gender: Male
- Sole propriator: No
- NPI: 1851408843
Dr. Ralph A. Defronzo MD
Internist
He is located at 701 South Zarzamora Street in San Antonio, TX 78207. Can help patients with the following: Abdominal Pain, Diarrhea, Growth Hormone Imbalance, Hiatal Hernia, Thyroid Cancer, Urinary Tract Infection (UTI). His National Provider Identifier (NPI) number is 1851408843. Appointment can be made via the phone number (210) 358-7500. He also has a website where you can get more information. The website can be found at http://www.universityhealthsystem.com/physician-directory/d/defronzo-ralph-a. He is affiliated with 1 practices.
Conditions treated
Dr. Ralph A. Defronzo, being an internist, treats the following conditions. Please be advised that this list may not be complete. For the full list of conditions treated, consult directly with Dr. Ralph A. Defronzo.
- Abdominal Pain
- Achondroplasia
- Acute Pain
- Addison's Disease
- Amyloidosis
- Anemia
- Arthritis
- Asthma
- Atherosclerosis
- Bladder Control
- Bone Loss
- Carcinoid Tumor
- Chest Pain
- Cholecystitis
- Chronic Obstructive Pulmonary Disease (COPD)
- Common Cold
- Constipation
- Cushing's Syndrome
- Cystitis
- Diabetes
- Diabetes Insipidus (DI)
- Diabetes Mellitus (DM) Type 1
- Diabetes Mellitus (DM) Type 2
- Diabetic Neuropathy
- Diarrhea
- Edema
- Fertility
- Fever
- Gastroesophageal Reflux Disease (GERD)
- General Care
- Goiter
- Graves' Disease
- Growth Hormone Imbalance
- Gynecomastia
- Headache
- Heart Disease
- Hiatal Hernia
- High Blood Pressure
- Hot Flashes
- Hypercalcemia
- Hyperglycemia
- Hyperlipidemia
- Hyperparathyroidism
- Hyperthyroidism
- Hypocalcemia
- Hypoglycemia
- Hyponatremia
- Hypoparathyroidism
- Hypothyroidism
- Influenza
- Inguinal Hernia
- Insulin Resistance (IR)
- Low Testosterone
- Metabolic Syndrome
- Migraine
- Nausea and Vomiting
- Obesity
- Osteoporosis
- Peptic Ulcer
- Prescription Refill
- Thyroid Cancer
- Thyroid Disease
- Thyroiditis
- Urethritis
- Urinary Tract Infection (UTI)
- Vitamin D Deficiency
- Wilson-Turner Syndrome
ACA Marketplace (Obamacare/HealthCare.gov) plan networks
Insurers selling ACA Marketplace (HealthCare.gov) plans list Dr. Ralph A. Defronzo as in-network for the following 2026 plans.
Health plans
Blue Cross and Blue Shield of Texas
Network data as of Jun 7, 2026, as reported by the insurer.
Show all 19 plans from Blue Cross and Blue Shield of Texas
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Blue Advantage Bronze HMO℠ 204 (27 plan variants) | HMO · Expanded Bronze | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Bronze HMO℠ 301 (14 plan variants) | HMO · Bronze | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Bronze HMO℠ Standard (27 plan variants) | HMO · Expanded Bronze | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Gold HMO℠ 206 (27 plan variants) | HMO · Gold | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Gold HMO℠ 603 (14 plan variants) | HMO · Gold | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Gold HMO℠ Standard (27 plan variants) | HMO · Gold | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Bronze℠ 303 (27 plan variants) | POS · Expanded Bronze | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Bronze℠ 305 (27 plan variants) | POS · Bronze | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Bronze℠ Standard (27 plan variants) | POS · Expanded Bronze | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Gold℠ 203 (27 plan variants) | POS · Gold | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Gold℠ 803 (27 plan variants) | POS · Gold | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Gold℠ Standard (27 plan variants) | POS · Gold | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Silver℠ 202 (27 plan variants) | POS · Silver | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Silver℠ 605 (27 plan variants) | POS · Silver | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Plus Silver℠ Standard (27 plan variants) | POS · Silver | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Security HMO℠ 200 (27 plan variants) | HMO · Catastrophic | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Silver HMO℠ 205 (27 plan variants) | HMO · Silver | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Silver HMO℠ 801 (14 plan variants) | HMO · Silver | Blue Advantage HMO | Accepting new patients |
| Blue Advantage Silver HMO℠ Standard (27 plan variants) | HMO · Silver | Blue Advantage HMO | Accepting new patients |
Community First
Network data as of May 18, 2026, as reported by the insurer.
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| University Community Care Plan by Community First - Gold Plan | EPO · Gold | Preferred | Accepting new patients |
| University Community Care Plan by Community First - Gold Plan Standard | EPO · Gold | Preferred | Accepting new patients |
| University Community Care Plan by Community First - Silver Plan | EPO · Silver | Preferred | Accepting new patients |
| University Community Care Plan by Community First - Silver Plan Standard | EPO · Silver | Preferred | Accepting new patients |
Harbor Health
Network data as of Sep 14, 2026, as reported by the insurer.
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Harbor Health G0 $0 Deductible $0 PCP $0 Mental Health Office Visit $0 Express Care | HMO · Gold | Preferred | Accepting new patients |
| Harbor Health G1S $30 PCP $30 Mental Health Office Visit $30 Express Care | HMO · Gold | Preferred | Accepting new patients |
| Harbor Health S1 $0 PCP $0 Mental Health Office Visit $0 Express Care | HMO · Silver | Preferred | Accepting new patients |
| Harbor Health S1S $40 PCP $40 Mental Health Office Visit $40 Express Care | HMO · Silver | Preferred | Accepting new patients |
Imperial Insurance Companies, Inc.
Network data as of Sep 16, 2025, as reported by the insurer.
Show all 7 plans from Imperial Insurance Companies, Inc.
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Imperial Preferred Bronze | HMO · Bronze | Preferred | Accepting new patients |
| Imperial Preferred Gold | HMO · Gold | Preferred | Accepting new patients |
| Imperial Preferred Gold Zero | HMO · Gold | Preferred | Accepting new patients |
| Imperial Preferred Silver | HMO · Silver | Preferred | Accepting new patients |
| Imperial Standard Bronze | HMO · Expanded Bronze | Standard | Accepting new patients |
| Imperial Standard Gold | HMO · Gold | Standard | Accepting new patients |
| Imperial Standard Silver | HMO · Silver | Standard | Accepting new patients |
This covers ACA Marketplace plans only, as reported by each insurer. It does not include employer, Medicare Advantage, or state-run exchange plans, and a plan missing from this list does not mean Dr. Ralph A. Defronzo is out of network. Insurer directories can be out of date, so always confirm with the insurer and the office before your visit.
Medicare Enrollment
Dr. Ralph A. Defronzo is enrolled to bill Medicare as a Practitioner - Endocrinology (also registered under: Practitioner - Internal Medicine, Practitioner - Nephrology) .
Bills through: University Of Texas Health Science Center At San Antonio
Based on Medicare's public enrollment records as of Jul 17, 2026. This reflects Medicare fee-for-service enrollment only and says nothing about other insurance, quality, outcomes, or board certification.
Payments received
Drug payment
| AstraZeneca | $817668 |
| Novo Nordisk | $357611 |
| Janssen | $135103 |
Other
| Promotional Speaking or Service | $897316 |
| Consulting | $293778 |
| Travel and Lodging | $248253 |
| Other | $31969 |
| Food and Beverage | $27967 |
Other ways to reach out
- Website: http://www.universityhealthsystem.com/physician-directory/d/defronzo-ralph-a
- Facebook: https://www.facebook.com/UniversityHealthSystem
Additional Specialities
- Endocrinologist
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- Gender: Female
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Questions & Answers
Does Dr. Ralph A. Defronzo accept patients with Community First?
Yes, Dr. Ralph A. Defronzo is listed in-network for Community First through the ACA Marketplace (Obamacare/HealthCare.gov). See the Marketplace plans section for details.
Where can you meet with Dr. Ralph A. Defronzo?
Dr. Ralph A. Defronzo's office is located at 701 South Zarzamora Street in San Antonio, TX 78207.
Does Dr. Ralph A. Defronzo have affiliation with practices?
Dr. Ralph A. Defronzo is affiliated with Treehouse Therapies.
What conditions does Dr. Ralph A. Defronzo treat?
Dr. Ralph A. Defronzo provides treatment for Abdominal Pain, Diarrhea, Growth Hormone Imbalance, Hiatal Hernia, Thyroid Cancer, Urinary Tract Infection (UTI). For the full list see this list.