Guillermo Lazo-Diaz, MD

Medical Oncology Internal Medicine

Internal Medicine

Guillermo Lazo-Diaz is a Medical Oncology Internal Medicine specialist based in Mcallen, TX with over 33 years of clinical experience. Medicare-enrolled per CMS records and offers virtual telehealth visits.

Also practices: HEMATOLOGY/ONCOLOGY

(956) 687-5150Mcallen, TX
Telehealth Available
NPI Active per CMS — Q2 2026|Medicare Enrolled|Order & Refer

Guillermo Lazo-Diaz, MD has practiced internal medicine for 33+ years, working in group practice. He has been practicing since 2006 — over 33 years. He regularly sees Medicare patients with hypertension, high cholesterol, and kidney disease (per CMS claims data). CMS MIPS quality score: 89.44/100 (2023).

At a glance

  • Federal MIPS score higher than 71% of MIPS-scored doctors in Texas
  • Virtual visits available — no app or travel required
1 of 258 Internal Medicine providers in TXSee all Internal Medicine in Mcallen33+ years experienceNPI since 2006

Older · 6372dNPPES updated 2008-12-11 · verify NPI on CMS · Verify license at Texas Medical Board

Contact & Location

Practice Location

1901 S 2nd St, Mcallen, TX 78503-1271

Fax: (956) 687-9546
CMS Clinical Data

How Does This Doctor Compare?

Based on Medicare data, this doctor scores better than 71% of doctors in Texas on federal quality measures.

MIPS Score

2023

89.44/100

Texas avg: 79.1 · US avg: 83.6

Higher than most doctors nationally(+5.8 pts)

Better than 71% of MIPS-scored doctors in Texas

How the government rates this doctor's Medicare care quality. Scores above 75 are considered good.

Opioid Rx

↓ Lower = better

11.81%

Texas avg: 5.2 · US avg: 5.1

Lower than most doctors nationally(+6.7 pts)

11.81% of this doctor's prescriptions are opioid pain medications. Lower means more cautious prescribing.

Generic Rx

↑ Higher = better

75%

Texas avg: 83.8 · US avg: 82.8

Lower than most doctors nationally(-7.8 pts)

How often this doctor prescribes affordable generic drugs instead of expensive brand-name ones.

Medicare Patients

353

Unique beneficiaries

Standard volume

Prescription Recipients

255

Patients prescribed

Prescriptions Written

1,253

Total claims

Total Medicare drug cost: $4.53M

Percentile rankings compared against 4,889 reporting peers in Texas.

Data Note: Sourced from CMS Medicare Provider Utilization & Payment Data. Percentile rankings compare this provider against all peers with reported data in the same state. Updated annually to reflect the latest federal reporting cycle.

Patient Condition Panel

What This Doctor Treats Most

Based on Medicare claims data — here's what patients commonly see this doctor for

Based on Medicare data, this doctor primarily manages Hypertension, High Cholesterol, and Chronic Kidney Disease.

Hypertension
Higher than avg (+5%)75%

High blood pressure — a leading risk factor for heart disease and stroke

US avg: 70.2%

↑ More patients than average (+5%) — a focus area for this doctor

High Cholesterol
Higher than avg (+5%)75%

Elevated cholesterol or triglycerides that increase heart disease risk

US avg: 70.4%

↑ More patients than average (+5%) — a focus area for this doctor

Chronic Kidney Disease
Higher than avg (+23%)53%

Gradual loss of kidney function over time, often linked to diabetes or hypertension

US avg: 29.6%

↑ More patients than average (+23%) — a focus area for this doctor

Diabetes
Higher than avg (+16%)50%

A condition where the body cannot properly regulate blood sugar levels

US avg: 34.5%

↑ More patients than average (+16%) — a focus area for this doctor

Arthritis
Lower than avg (-3%)46%

Joint inflammation causing pain, swelling, and stiffness

US avg: 49.3%

↓ Fewer patients than average (-3%) — less common here

Cancer
Higher than avg (+21%)42%

Diseases involving abnormal cell growth with potential to spread to other body parts

US avg: 20.8%

↑ More patients than average (+21%) — a focus area for this doctor

Ischemic Heart Disease
Higher than avg (+6%)38%

Reduced blood flow to the heart muscle, commonly known as coronary artery disease

US avg: 31.7%

↑ More patients than average (+6%) — a focus area for this doctor

Anxiety Disorders
Lower than avg (-5%)29%

Excessive worry or fear that interferes with daily life

US avg: 34.1%

↓ Fewer patients than average (-5%) — less common here

GeneralBehavioralNational avg

Percentage of this provider's Medicare patients diagnosed with each condition. Source: CMS Utilization Data.

Industry Payment Transparency

$442 received from industry

15 transactions reported in 2024 ·Low tier

View on CMS Open Payments →

Payments include consulting fees, speaking honoraria, food & beverage, travel, research support, and ownership interests from drug and medical device manufacturers. Disclosure is required by the federal Physician Payments Sunshine Act. These payments do not necessarily indicate conflicts of interest. National median: $338 across 136 000 tracked providers.

Tiers — Low: under $500 · Moderate: $500-5 000 · High: $5 000-25 000 · Very High: $25 000+. Source: CMS Open Payments 2024, attributed to Guillermo Lazo-Diaz's NPI.

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Background & Specialty

Education, training, and specialty classification from CMS NPPES and Medicare records.

Career Journey
  1. 33 years in practice

    Senior practitioner

Internal MedicineMedical Oncology in McallenAllopathic & Osteopathic Physicians

Medical oncologists diagnose and treat cancer using chemotherapy, immunotherapy, targeted therapy, and hormone therapy. They coordinate care with surgical oncologists and radiation oncologists for comprehensive cancer treatment.

Taxonomy: 207RX0202X

Practice Footprint

Mailing address

Po Box 911230, Dallas, TX 75391-1230

Differs from practice location

Virtual Medical Oncology Care With Guillermo Lazo-Diaz

NPPES records indicate this provider offers telehealth services. Contact the office to confirm availability and scheduling.

Schedule a virtual visit with Guillermo Lazo-Diaz for blood pressure monitoring, cholesterol management, kidney care follow-ups — no travel to Mcallen required. The office sends a secure video link before your appointment. Most visits take 15–30 minutes. Medicare enrolled per CMS records.

Frequently Asked Questions

Common questions about Guillermo Lazo-Diaz

Dr. Lazo-Diaz is listed as active in the NPI registry with telehealth listed in Mcallen, TX. NPI status alone doesn't confirm open availability — call the office to confirm. Phone: (956) 687-5150.

Verified across 6 federal data sources

Sourced from CMS NPPES · OIG LEIE · CMS QPP 2023 · CMS Medicare Part D · CMS Open Payments 2024 · CMS Physician Comparator. See Data Methodology.

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Medical Disclaimer: NPI Telehealth is a provider directory for informational purposes only. This page does not constitute medical advice, diagnosis, or treatment recommendations. Provider data is sourced from the CMS NPPES federal registry and public Medicare datasets. NPI Telehealth does not verify clinical qualifications beyond federal records. Data may not reflect real-time availability — always contact the provider's office directly to confirm details before seeking care.

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