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BRYON CALLAHAN M.D.
NPI 1659717734
Emergency Medicine in Houston, TX

Active since May 16, 2013PECOS EnrolledAccepts Medicare Assignment
1635 NORTH LOOP W, HOUSTON, TX 77008(713) 867-2000 Get Directions Write a Review

NPPES record last updated: September 13, 2024. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Sep 13, 2024, Aug 27, 2018 (2 updates tracked since 2018).

About Bryon Callahan M.d. NPPES

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

BRYON CALLAHAN M.D. (NPI 1659717734) is an individual emergency medicine provider in Houston, Texas, licensed in Texas (Q8216) and active in the NPI registry since May 2013. He is enrolled in Medicare PECOS, is affiliated with Memorial Hermann Hospital System, and maintains a secondary practice location in Charlotte.

NPPES Registry Identity

NPI1659717734
Entity TypeIndividualMale
Primary Taxonomy207P00000X
Provider Legal NameBRYON CALLAHANCredential: M.D.
Location Address1635 NORTH LOOP WHouston, TX 77008
Mailing Address1635 North Loop WHouston, TX 77008-1532
Phone(713) 867-2000
Sole ProprietorYes
Medical School CMSTexas Tech University Health Science Center School Of MedicineGraduated 2013
Enumeration DateMay 16, 2013
Last NPPES UpdateSeptember 13, 20242 updates tracked since enumeration
NPPES CertifiedSeptember 13, 2024
✔ NPI 1659717734 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyEmergency MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207P00000X
Licenses✔ Licensed in TX · Q8216✔ Licensed in NC · 191711
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.
1635 NORTH LOOP W, Houston, TX 77008
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Secondary Practice Location 1

Location 11000 Blythe Blvd, MEB 3Charlotte, NC 28203-5812 · Phone (704) 355-2000

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Blue Cross and Blue Shield of Texas, Oscar Insurance Company.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

Bryon Callahan 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 ID6800186479
PECOS Enrollment IDI20160609002526
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

3

Medicare enrollment records show Bryon Callahan reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Memorial Hermann Hospital Based Physician Group
7.2 mi
Emergency Medicine
929 GESSNER RD STE 2700
Houston, TX 77024
  • Reassigned Medicare billing, Texas enrollment
  • 408 clinicians in this Medicare group
NPI 1295363497 (713) 242-2712
Integrative Emergency Services Physician Group-Houston PLLC
20 mi
Emergency Medicine
4500 E SAM HOUSTON PKWY S
Pasadena, TX 77505
  • Reassigned Medicare billing, Texas enrollment
  • 644 clinicians in this Medicare group
NPI 1801458708 (713) 948-7000
Acs Primary Care Physicians Southwest, PA
284 mi
Emergency Medicine
1900 HOSPITAL BLVD
Gainesville, TX 76240
  • Reassigned Medicare billing, Texas enrollment
  • 1,193 clinicians in this Medicare group
NPI 1538101019 (925) 924-1600

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 3

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.
172 services162 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.
121 services114 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.
21 services19 patients

Hospital Affiliations CMS Care Compare 2

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

Memorial Hermann Hospital System

Acute Care Hospitals · Houston, TX
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number450184
Location1635 North Loop WestHouston, TX 77008 · Harris County
Emergency services Birthing friendly

Oakbend Medical Center

Acute Care Hospitals · Richmond, TX
2/5 CMS rating
OwnershipGovernment - Hospital District or Authority
CMS Certification Number450330
Location1705 Jackson StRichmond, TX 77469 · Fort Bend County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 77008 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
$90.40 typical visit price
range $58.24 – $176.98
Typical copayment $22.60 (range $14.56 – $44.24)
Most-billed visit code 99203
Established Patient
$102.71 typical visit price
range $18.60 – $143.93
Typical copayment $25.67 (range $4.65 – $35.98)
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.

HYUNG J KIM MD
Anesthesiology
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (713) 540-6980
THANG HLEI KIM
Nurse Practitioner (Acute Care)
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (713) 867-2000
DAYNA EVELYN MCDANIEL CRNA
Nurse Anesthetist, Certified Registered
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (713) 867-2000
STACEY WUNGSEE LAU OTR
Occupational Therapist
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (713) 803-6778
LOUIS T PENA CRNA
Nurse Anesthetist, Certified Registered
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (713) 400-2990
MEMORIAL HERMANN HEALTH SYSTEM
Clinic/Center (Radiology)
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (713) 867-3336
TATSUO YAMAKAWA M.D.
Emergency Medicine
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (713) 338-6565
MAHREEN UMATIYA FNP-C
Nurse Practitioner
1635 NORTH LOOP W
HOUSTON, TX 77008
Harris County (904) 372-3943

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 Bryon Callahan's NPI number?

The NPI number for Bryon Callahan is 1659717734. It was assigned to this individual provider in the NPPES registry on May 16, 2013.

Where is Bryon Callahan located?

Bryon Callahan practices at 1635 North Loop W, Houston, TX 77008. The listed phone number is (713) 867-2000.

What is Bryon Callahan's specialty?

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

Is Bryon Callahan enrolled in Medicare?

Yes. Bryon Callahan 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 Bryon Callahan's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Bryon Callahan reassigns Medicare benefits to 3 organizations: Memorial Hermann Hospital Based Physician Group (Houston, TX), Integrative Emergency Services Physician Group-Houston PLLC (Pasadena, TX) and Acs Primary Care Physicians Southwest, PA (Gainesville, TX). 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 Bryon Callahan's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Bryon Callahan accept?

Health plans from Blue Cross and Blue Shield of Texas and Oscar Insurance Company list Bryon Callahan 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 Bryon Callahan affiliated with any hospitals?

According to CMS data, Bryon Callahan is affiliated with Memorial Hermann Hospital System and Oakbend Medical Center.

When was this NPI record last updated?

The NPPES record for Bryon Callahan was last updated on September 13, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 years 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.