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NORTH TEXAS TOXICOLOGY PLLC
NPI 1821735143
Emergency Medicine - Medical Toxicology in Dallas, TX

Active since May 18, 2022
4835 LBJ FWY STE 900, DALLAS, TX 75244(469) 420-5544 Get Directions Write a Review

NPPES record last updated: August 12, 2025. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Aug 12, 2025, Nov 22, 2022, May 18, 2022 (3 updates tracked since 2022).

About North Texas Toxicology Pllc NPPES

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

NORTH TEXAS TOXICOLOGY PLLC (NPI 1821735143) is a healthcare organization registered as a medical toxicology in Dallas, Texas and active in the NPI registry since May 2022. The organization lists Nestor Zenarosa, Authorized Offical, as its authorized official.

NPPES Registry Identity

NPI1821735143
Entity TypeOrganization
Primary Taxonomy207PT0002X
Legal Business NameNORTH TEXAS TOXICOLOGY PLLC
Location Address4835 LBJ FWY STE 900Dallas, TX 75244-6001
Mailing AddressPo Box 650444, Dept 134Dallas, TX 75265
Phone(469) 420-5544
Organization SubpartNo
Authorized OfficialNestor ZenarosaAuthorized Offical · (469) 420-5544
Enumeration DateMay 18, 2022
Last NPPES UpdateAugust 12, 20253 updates tracked since enumeration
NPPES CertifiedAugust 12, 2025
✔ NPI 1821735143 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyEmergency Medicine · Medical ToxicologyAllopathic & Osteopathic Physicians
Taxonomy Code207PT0002X
Definition
Medical toxicologists are physicians who specialize in the prevention, evaluation, treatment and monitoring of injury and illness from exposures to drugs and chemicals, as well as biological and radiological agents. Medical toxicologists care for people in clinical, academic, governmental and public health settings, and provide poison control center leadership. Important areas of medical toxicology include acute drug poisoning, adverse drug events, drug abuse, addiction and withdrawal, chemicals and hazardous materials, terrorism preparedness, venomous bites and stings and environmental and workplace exposures.
4835 LBJ FWY STE 900, Dallas, TX 75244
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Group Practice 1

Group TaxonomyThis provider is a business group of one or more individual practitioners, who practice with different areas of specialization.193200000X MULTI-SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

North Texas Toxicology Pllc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

6

Medicare enrollment records show 6 clinicians reassign Medicare billing to North Texas Toxicology PLLC, which bills Medicare for the services they deliver. Of these, 3 practice within 10 miles. They are listed nearest first.

Clinicians, nearest first (6)

Josue Zozaya
Emergency Medicine
NPI 1528697026
6201 HARRY HINES BLVD
Dallas, TX 75390
(214) 645-9729
✔ PECOS✔ Accepts Medicare7.7 mi
Kim Aldy, DO
Internal Medicine
NPI 1326427964
5200 HARRY HINES BLVD
Dallas, TX 75235
(214) 590-8000
✔ PECOS✔ Accepts Medicare8.0 mi
Todd Phillips, M.D.
Emergency Medicine
NPI 1205122660
5323 HARRY HINES BLVD STOP 7200
Dallas, TX 75390
(214) 648-3916
✔ PECOS✔ Accepts Medicare8.1 mi
Joshua Mcfalls, MD
Emergency Medicine
NPI 1255785457
4502 E 41ST ST
Tulsa, OK 74135
(918) 579-2367
✔ PECOS✔ Accepts Medicare225 mi
Samuel Ralston, D.O.
Emergency Medicine
NPI 1144457276
2817 REILLY ST WOMACK ARMY MEDICAL CENTER
Fort Bragg, NC 28310
(910) 432-5080
✔ PECOS✔ Accepts Medicare1,033 mi
Jessica Weiland
Emergency Medicine
NPI 1336420595
2545 SCHOENERSVILLE RD
Bethlehem, PA 18017
(484) 884-2888
✔ PECOS✔ Accepts Medicare1,297 mi

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

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 North Texas Toxicology PLLC's NPI number?

The NPI number for North Texas Toxicology PLLC is 1821735143. It was assigned to this organization in the NPPES registry on May 18, 2022.

Where is North Texas Toxicology PLLC located?

North Texas Toxicology PLLC is located at 4835 Lbj Fwy Ste 900, Dallas, TX 75244. The listed phone number is (469) 420-5544.

What is North Texas Toxicology PLLC's specialty?

The primary specialty registered for this NPI is Emergency Medicine, specializing in Medical Toxicology, with taxonomy code 207PT0002X.

Is North Texas Toxicology PLLC enrolled in Medicare?

Yes. North Texas Toxicology PLLC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through North Texas Toxicology PLLC?

According to the CMS Revalidation Reassignment List (October 2026 release), 6 clinicians in 2 Medicare specialties reassign their Medicare billing to North Texas Toxicology PLLC. A 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 the clinician's services. The largest specialties are Emergency Medicine (5) and Internal Medicine (1). Of these, 3 practice within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for North Texas Toxicology PLLC was last updated on August 12, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 14 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.