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DR. FERNANDO CRISTOBAL DIAZ MD
NPI 1902333545
Internal Medicine - Hematology & Oncology in Mcallen, TX

Active since May 14, 2017PECOS EnrolledAccepts Medicare Assignment
5137 LOST CREEK LN, MCALLEN, TX 78504(919) 966-1996(919) 966-6735 Get Directions Write a Review

NPPES record last updated: August 21, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Aug 21, 2026, Sep 12, 2024, Jul 3, 2020 and 1 more (4 updates tracked since 2017).

About Dr. Fernando Cristobal Diaz Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. FERNANDO CRISTOBAL DIAZ MD (NPI 1902333545) is an individual hematology & oncology provider in Mcallen, Texas, licensed in Texas (V2724) and active in the NPI registry since May 2017. He is enrolled in Medicare PECOS, is affiliated with Watauga Medical Center, and maintains a secondary practice location in Boone.

NPPES Registry Identity

NPI1902333545
Entity TypeIndividualMale
Primary Taxonomy207RH0003X
Provider Legal NameDR. FERNANDO CRISTOBAL DIAZCredential: MD
Location Address5137 LOST CREEK LNMcallen, TX 78504-9783
Mailing Address5137 Lost Creek LnMcallen, TX 78504-9783 · (919) 966-1996 · Fax (919) 966-6735
Phone(919) 966-1996
Fax(919) 966-6735
Sole ProprietorYes
Medical School CMSOtherGraduated 2011
Enumeration DateMay 14, 2017
Last NPPES UpdateAugust 21, 20264 updates tracked since enumeration
NPPES CertifiedAugust 21, 2026
✔ NPI 1902333545 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Hematology & OncologyAllopathic & Osteopathic Physicians
Taxonomy Code207RH0003X
License✔ Licensed in TX · V2724
Definition
An internist doctor of osteopathy that specializes in the treatment of the combination of hematology and oncology disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine WAS able to obtain a Certificate of Special Qualifications in the field of Hematology and Oncology. The Certificate is NO longer offered.
5137 LOST CREEK LN, Mcallen, TX 78504
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Secondary Practice Location 1

Location 1338 Deerfield RdBoone, NC 28607-5008 · Phone (828) 262-4100

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Arizona Complete Health, Ambetter from Arkansas Health & Wellness, Ambetter from Louisiana Healthcare Connections and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Fernando Cristobal Diaz Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID6002239936
PECOS Enrollment IDI20240920000541
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignment

Medicare enrollment records show Fernando Diaz reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Texas Oncology PA
269 mi
Medical Oncology
4101 JAMES CASEY ST STE 100
Austin, TX 78745
  • Reassigned Medicare billing, Texas enrollment
  • 1,054 clinicians in this Medicare group
NPI 1972770303 (972) 997-8000

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 8

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Insertion of needle into vein for collection of blood sample 36415
This procedure involves inserting a small needle into a vein, typically in your arm, to collect a blood sample. It's a quick and simple process to help diagnose or monitor health conditions. You may feel a small prick, but discomfort is minimal.
52 services37 patients
Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count 85025
A Complete Blood Cell Count is a common test that measures various components of the blood, including red cells (carry oxygen), white cells (fight infection), and platelets (help blood clot). An automated test ensures accuracy. The differential count provides detailed information about white cell types.
49 services35 patients
Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
41 services36 patients
Blood test, comprehensive group of blood chemicals 80053
A comprehensive group of blood chemicals test, also known as a comprehensive metabolic panel, is a blood test that measures your sugar level, electrolyte and fluid balance, kidney function, and liver function. This helps to check your body's overall health.
38 services32 patients
Injection of drug or substance under skin or into muscle 96372
This procedure involves administering medication directly under the skin or into a muscle. A small needle is used to inject the drug, allowing it to be absorbed quickly into the bloodstream. It's a common method for delivering a variety of medications.
23 services13 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
17 services11 patients

Hospital Affiliations CMS Care Compare 4

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Watauga Medical Center

Acute Care Hospitals · Boone, NC
3/5 CMS rating
OwnershipGovernment - Local
CMS Certification Number340051
Location336 Deerfield RoadBoone, NC 28607 · Watauga County
Emergency services Birthing friendly

South Texas Health System

Acute Care Hospitals · Edinburg, TX
3/5 CMS rating
OwnershipProprietary
CMS Certification Number450119
Location1102 W Trenton RoadEdinburg, TX 78539 · Hidalgo County
Emergency services Birthing friendly

Rio Grande Regional Hospital

Acute Care Hospitals · Mcallen, TX
3/5 CMS rating
OwnershipProprietary
CMS Certification Number450711
Location101 E Ridge RdMcallen, TX 78503 · Hidalgo County
Emergency services Birthing friendly

Doctors Hosptal At Renaissance

Acute Care Hospitals · Edinburg, TX
3/5 CMS rating
OwnershipPhysician
CMS Certification Number450869
Location5501 South MccollEdinburg, TX 78539 · Hidalgo County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 78504 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$166.88 typical visit price
range $54.84 – $166.88
Typical copayment $41.72 (range $13.71 – $41.72)
Most-billed visit code 99205
Established Patient
$97.05 typical visit price
range $17.52 – $136.11
Typical copayment $24.26 (range $4.38 – $34.02)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Fernando Diaz's NPI number?

The NPI number for Fernando Diaz is 1902333545. It was assigned to this individual provider in the NPPES registry on May 14, 2017.

Where is Fernando Diaz located?

Fernando Diaz practices at 5137 Lost Creek Ln, Mcallen, TX 78504. The listed phone number is (919) 966-1996.

What is Fernando Diaz's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Hematology & Oncology, with taxonomy code 207RH0003X.

Is Fernando Diaz enrolled in Medicare?

Yes. Fernando Diaz is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organization bills Medicare for Fernando Diaz's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Fernando Diaz reassigns Medicare benefits to Texas Oncology PA (Austin, TX). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Fernando Diaz's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Fernando Diaz accept?

Health plans from Ambetter from Arizona Complete Health, Ambetter from Arkansas Health & Wellness, Ambetter from Louisiana Healthcare Connections, Ambetter from Superior HealthPlan and Ambetter of Oklahoma and 6 other insurers list Fernando Diaz as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Fernando Diaz affiliated with any hospitals?

According to CMS data, Fernando Diaz is affiliated with Watauga Medical Center, South Texas Health System, Rio Grande Regional Hospital and Doctors Hosptal At Renaissance.

When was this NPI record last updated?

The NPPES record for Fernando Diaz was last updated on August 21, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.