1. Home
  2. Directory
  3. Texas
  4. Round Rock
  5. Emergency Medicine
  6. NPI Profile

DR. LUIS ANGEL REYES MERCADO M.D.
NPI 1669676979
Emergency Medicine in Round Rock, TX

Active since June 12, 2007PECOS EnrolledAccepts Medicare Assignment
300 UNIVERSITY BLVD, ROUND ROCK, TX 78665(512) 509-0100(512) 218-6330 Get Directions Write a Review

NPPES record last updated: June 24, 2026. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Dr. Luis Angel Reyes Mercado M.d. NPPES

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

DR. LUIS ANGEL REYES MERCADO M.D. (NPI 1669676979) is an individual emergency medicine provider in Round Rock, Texas, licensed in Texas (P4804) and active in the NPI registry since June 2007. He is enrolled in Medicare PECOS, is affiliated with South Texas Health System, and is a graduate of University Central Del Caribe Escuela De Medicina (2005).

NPPES Registry Identity

NPI1669676979
Entity TypeIndividualMale
Primary Taxonomy207P00000X
Provider Legal NameDR. LUIS ANGEL REYES MERCADOCredential: M.D.
Location Address300 UNIVERSITY BLVDRound Rock, TX 78665-1032
Mailing AddressPo Box 844658Dallas, TX 75284-4658 · (800) 994-0371 · Fax (254) 215-9722
Phone(512) 509-0100
Fax(512) 218-6330
Sole ProprietorYes
Medical School CMSUniversity Central Del Caribe Escuela De MedicinaGraduated 2005
Enumeration DateJune 12, 2007
Last NPPES UpdateJune 24, 2026
NPPES CertifiedJune 24, 2026
✔ NPI 1669676979 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyEmergency MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207P00000X
License✔ Licensed in TX · P4804
Definition
An emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospital setting by directing emergency medical technicians and in the emergency department. The emergency physician provides immediate recognition, evaluation, care, stabilization and disposition of a generally diversified population of adult and pediatric patients in response to acute illness and injury.
300 UNIVERSITY BLVD, Round Rock, TX 78665
Open in Google Maps ↗

Other Names 1

Professional Name (2)Dr. Luis Reyes Mercado Md

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. Luis Angel Reyes Mercado M.d. 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 ID4587828439
PECOS Enrollment IDI20130726000021
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 Reassignments

8

Medicare enrollment records show Luis Reyes Mercado reassigns Medicare billing to 8 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Scott & White Hospital - Taylor
16 mi
Emergency Medicine
305 MALLARD LN
Taylor, TX 76574
  • Reassigned Medicare billing, Texas enrollment
  • 110 clinicians in this Medicare group
NPI 1659366557 (512) 352-7611
Longhorn Emergency Medical Associates PA
19 mi
Emergency Medicine
919 E 32ND ST
Austin, TX 78705
  • Reassigned Medicare billing, Texas enrollment
  • 547 clinicians in this Medicare group
NPI 1649669672 (925) 251-6901
Comal Emergency Physicians, PLLC
51 mi
Emergency Medicine
1301 WONDER WORLD DR
San Marcos, TX 78666
  • Reassigned Medicare billing, Texas enrollment
  • 137 clinicians in this Medicare group
NPI 1588438675 (512) 353-8979
Emergency Medicine Services Of Tx, PLLC
90 mi
Emergency Medicine
7700 FLOYD CURL DR
San Antonio, TX 78229
  • Reassigned Medicare billing, Texas enrollment
  • 1,452 clinicians in this Medicare group
NPI 1245938729 (210) 575-4000
Texas Medicine Resources, LLP
154 mi
Emergency Medicine
6451 BRENTWOOD STAIR RD, SUITE 200
Fort Worth, TX 76112
  • Reassigned Medicare billing, Texas enrollment
  • 545 clinicians in this Medicare group
NPI 1376581900 (817) 496-9700
Century Integrated Partners, Inc
163 mi
Emergency Medicine
3500 GASTON AVE
Dallas, TX 75246
  • Reassigned Medicare billing, Texas enrollment
  • 1,044 clinicians in this Medicare group
NPI 1447615711 (214) 820-2505
Texas Emergency Medicine Group, LLP
182 mi
Emergency Medicine
1301 MONTGOMERY RD
Graham, TX 76450
  • Reassigned Medicare billing, Texas enrollment
  • 57 clinicians in this Medicare group
NPI 1134774722 (817) 507-0796
Governor Juan F. Luis Hospital & Medical Center
General Acute Care Hospital
#4007 ESTATE DIAMOND RUBY
Christiansted, St. Croix, VI 00821
  • Reassigned Medicare billing, U.S. Virgin Islands enrollment
  • 331 clinicians in this Medicare group
NPI 1972503647 (340) 778-6311

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 4

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.

Emergency department visit with high level of medical decision making 99285
An emergency department visit for severe conditions is when you urgently seek medical help due to serious health issues. These could be severe injuries, breathing problems, unbearable pain, or sudden severe illness. Doctors and nurses will provide immediate care to stabilize your condition.
287 services278 patients
Emergency department visit with moderate level of medical decision making 99284
An emergency department visit for a high-severity issue means you're experiencing a serious health problem that needs immediate attention. This could be a severe injury, serious illness, or life-threatening condition. Medical professionals will provide urgent care to stabilize your condition.
76 services75 patients
Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 93010
A routine electrocardiogram (ECG) with 12 leads is a simple, non-invasive test that records the electrical activity of your heart. It helps in identifying heart conditions by detecting irregularities in your heart rhythms. The results are interpreted and a report is provided.
54 services54 patients
Critical care, first 30-74 minutes 99291
Critical care involves immediate and constant attention by a team of specially-trained health professionals. It's for patients with life-threatening conditions, requiring first 30-74 minutes of intense monitoring and treatment.
14 services14 patients

Hospital Affiliations CMS Care Compare 5

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

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

Christus Santa Rosa Hospital-San Marcos

Acute Care Hospitals · San Marcos, TX
2/5 CMS rating
OwnershipVoluntary non-profit - Church
CMS Certification Number450272
Location1301 Wonder World DriveSan Marcos, TX 78666 · Hays County
Emergency services Birthing friendly

St David's South Austin Medical Center

Acute Care Hospitals · Austin, TX
5/5 CMS rating
OwnershipProprietary
CMS Certification Number450713
Location901 West Ben White BlvdAustin, TX 78704 · Travis County
Emergency services Birthing friendly

Baylor Scott & White Medical Center - Round Rock

Acute Care Hospitals · Round Rock, TX
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number670034
Location300 University BlvdRound Rock, TX 78664 · Williamson County
Emergency services Birthing friendly

Baylor Scott & White Medical Center- Austin

Acute Care Hospitals · Austin, TX
OwnershipVoluntary non-profit - Private
CMS Certification Number670136
Location5245 W Us 290Austin, TX 78735 · Travis County

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 78665 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
$84.92 typical visit price
range $54.84 – $166.88
Typical copayment $21.23 (range $13.71 – $41.72)
Most-billed visit code 99203
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.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

BRENNEN J. BEATTY MD
Emergency Medicine
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
KATHLEEN SUSAN GRADY-GREENE ARNP
Nurse Practitioner (Neonatal)
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0200
MATTHEW RYAN DANLEY D.O.
Anesthesiology
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
CODY R. QUIRK M.D.
Radiology (Diagnostic Radiology)
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
CAITLIN O'CONNOR CRNA
Nurse Anesthetist, Certified Registered
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100
MARCEL ALBERT GRAF AA-C
Anesthesiologist Assistant
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0200
SADIE JOHNSON RN
Registered Nurse
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (940) 595-0169
DR. JACLYN NGOC MINH NGUYEN MD
Emergency Medicine
300 UNIVERSITY BLVD
ROUND ROCK, TX 78665
Williamson County (512) 509-0100

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 Luis Reyes Mercado's NPI number?

The NPI number for Luis Reyes Mercado is 1669676979. It was assigned to this individual provider in the NPPES registry on June 12, 2007. The provider is also known as Dr. Luis Reyes Mercado MD.

Where is Luis Reyes Mercado located?

Luis Reyes Mercado practices at 300 University Blvd, Round Rock, TX 78665. The listed phone number is (512) 509-0100.

What is Luis Reyes Mercado's specialty?

The primary specialty registered for this NPI is Emergency Medicine with taxonomy code 207P00000X.

Is Luis Reyes Mercado enrolled in Medicare?

Yes. Luis Reyes Mercado 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 organizations bill Medicare for Luis Reyes Mercado's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Luis Reyes Mercado reassigns Medicare benefits to 8 organizations: Scott & White Hospital - Taylor (Taylor, TX), Longhorn Emergency Medical Associates PA (Austin, TX), Comal Emergency Physicians, PLLC (San Marcos, TX), Emergency Medicine Services Of Tx, PLLC (San Antonio, TX), Texas Medicine Resources, LLP (Fort Worth, TX) and 3 more organizations, listed in the Medicare section above. Each 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 Luis Reyes Mercado's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Luis Reyes Mercado 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 5 other insurers list Luis Reyes Mercado 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 Luis Reyes Mercado affiliated with any hospitals?

According to CMS data, Luis Reyes Mercado is affiliated with South Texas Health System, Christus Santa Rosa Hospital-San Marcos, St David's South Austin Medical Center, Baylor Scott & White Medical Center - Round Rock and Baylor Scott & White Medical Center- Austin.

When was this NPI record last updated?

The NPPES record for Luis Reyes Mercado was last updated on June 24, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.