Guillermo Lazo Diaz, MD

Medicare activity in 2024

Official CMS public-use data for Guillermo Lazo Diaz, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Most frequent services

1. Injection, ferumoxytol, for treatment of iron deficiency anemia, 1 mg (non-esrd use) (Q0138)7,650 services
2. Low osmolar contrast material, 300-399 mg/ml iodine concentration, per ml (Q9967)1,785 services
3. Injection, ferric derisomaltose, 10 mg (J1437)1,400 services
4. Injection, epoetin alfa-epbx, biosimilar, (retacrit) (for non-esrd use), 1000 units (Q5106)1,040 services
5. Insertion of needle into vein for collection of blood sample (36415)710 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

• High blood pressure75%
• High cholesterol75%
• Chronic kidney disease49%
• Diabetes47%
• Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)44%
• Arthritis42%

Hospitals where Guillermo Lazo Diaz works

Medicare's Facility Affiliation Data lists Guillermo Lazo Diaz at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

• Doctors Hospital at RenaissanceEdinburg, TX · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 450869
• Rio Grande Regional HospitalMcAllen, TX · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 450711
• South Texas Health SystemEdinburg, TX · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 450119

Practice locations

Addresses where Guillermo Lazo Diaz is enrolled with Medicare (CMS data updated October 2, 2026).

• 1901 S 2nd StMcAllen, TX 78503 (956) 687‑5150

Group practices

Medicare enrollment lists Guillermo Lazo Diaz as a member of this group (CMS data updated October 2, 2026).

• Texas Oncology PA1,014 clinicians in the group

Specialties

• Medical Oncologyprimary
• Hematology/Oncologyalso

Find other Medical Oncology doctors in Texas →

Other oncologists in McAllen

Clinicians with the same Medicare primary specialty in McAllen, TX — not a recommendation.

• Nirupama G. Shekar, MD
• Suresh Ratnam, MD
• Alvaro Restrepo, MD

All oncologists in McAllen →

Other clinicians in Texas Oncology PA

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

• Shrinivas M. Diggikar, MD
• Claude A. Denham, MD
• Diana M. Hook, MD
• Andrew Olguin, NP
• Camille E. Jones, PA
• Curtis L. Studey, MD

Clinician information

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
6. Medicare Care Compare — official Medicare tool to look up clinicians