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GRANT MICHAEL WALLENFELSZ MD
NPI 1194353318
Emergency Medicine in Agana Heights, GU

Active since April 01, 2020PECOS EnrolledAccepts Medicare Assignment
BLDG #50 FARENHOLT AVE, AGANA HEIGHTS, GU 96910(671) 344-9340 Get Directions Write a Review

NPPES record last updated: October 2, 2025. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Oct 10, 2024, Jul 28, 2023, Apr 1, 2020 (3 updates tracked since 2020).

About Grant Michael Wallenfelsz Md NPPES

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

GRANT MICHAEL WALLENFELSZ MD (NPI 1194353318) is an individual emergency medicine provider in Agana Heights, Guam, licensed in Texas (T3715) and active in the NPI registry since April 2020. He is enrolled in Medicare PECOS, is affiliated with Guam Regional Medical City, and is a graduate of Florida State University College Of Medicine (2020).

NPPES Registry Identity

NPI1194353318
Entity TypeIndividualMale
Primary Taxonomy207P00000X
Provider Legal NameGRANT MICHAEL WALLENFELSZCredential: MD
Location AddressBLDG #50 FARENHOLT AVEAgana Heights, GU 96910
Mailing AddressPsc 455 Box 208Fpo, AP 96540-0003
Phone(671) 344-9340
Sole ProprietorNo
Medical School CMSFlorida State University College Of MedicineGraduated 2020
Enumeration DateApril 1, 2020
Last NPPES UpdateOctober 2, 20253 updates tracked since enumeration
NPPES CertifiedOctober 2, 2025
✔ NPI 1194353318 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 · T3715✔ Licensed in CA · A187218✔ Licensed in GU · M-2480
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.

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Grant Michael Wallenfelsz 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 ID9335671106
PECOS Enrollment IDI20241017002667, I20250918004578
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.

Areas of Expertise CMS Part B claims

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.
13 services13 patients

Hospital Affiliations CMS Care Compare

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

Guam Regional Medical City

Acute Care Hospitals · Dededo, GU
OwnershipVoluntary non-profit - Private
CMS Certification Number650003
Location133 Route 3Dededo, GU 96929 · Guam County
Emergency services

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 96910 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
$92.50 typical visit price
range $60.53 – $180.05
Typical copayment $23.12 (range $15.13 – $45.01)
Most-billed visit code 99203
Established Patient
$105.65 typical visit price
range $20.09 – $147.56
Typical copayment $26.41 (range $5.02 – $36.89)
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 2

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

BRYAN MASON FAULK DENTAL TECHNICIAN
Dental Assistant
BLDG #50 FARENHOLT AVE
AGANA HEIGHTS, GU 96910
Guam (671) 344-9493
CARRIE MARGESON
Pharmacist
BLDG #50 FARENHOLT AVE
TUTUHAN, GU 96910
Guam (670) 344-9354

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 Grant Wallenfelsz's NPI number?

The NPI number for Grant Wallenfelsz is 1194353318. It was assigned to this individual provider in the NPPES registry on April 1, 2020.

Where is Grant Wallenfelsz located?

Grant Wallenfelsz practices at Bldg #50 Farenholt Ave, Agana Heights, GU 96910. The listed phone number is (671) 344-9340.

What is Grant Wallenfelsz's specialty?

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

Is Grant Wallenfelsz enrolled in Medicare?

Yes. Grant Wallenfelsz 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.

Is Grant Wallenfelsz affiliated with any hospitals?

According to CMS data, Grant Wallenfelsz is affiliated with Guam Regional Medical City.

When was this NPI record last updated?

The NPPES record for Grant Wallenfelsz was last updated on October 2, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 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.