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MR. WILLIAM J BARKER MD
NPI 1770599847
Emergency Medicine - Emergency Medical Services in Warrenton, VA

Active since July 31, 2006PECOS Enrolled
500 HOSPITAL DR, WARRENTON, VA 20186(540) 349-0595(540) 349-0587 Get Directions Write a Review

NPPES record last updated: April 30, 2008. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Mr. William J Barker Md NPPES

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

MR. WILLIAM J BARKER MD (NPI 1770599847) is an individual emergency medical services provider in Warrenton, Virginia, licensed in Virginia (0101036994) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1770599847
Entity TypeIndividualMale
Primary Taxonomy207PE0004X
Provider Legal NameMR. WILLIAM J BARKERCredential: MD
Location Address500 HOSPITAL DRWarrenton, VA 20186-3027
Mailing AddressPo Box 223323Chantilly, VA 20153-3323 · (540) 349-0595
Phone(540) 349-0595
Fax(540) 349-0587
Sole ProprietorNo
Enumeration DateJuly 31, 2006
Last NPPES UpdateApril 30, 2008
✔ NPI 1770599847 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyEmergency Medicine · Emergency Medical ServicesAllopathic & Osteopathic Physicians
Taxonomy Code207PE0004X
License✔ Licensed in VA · 0101036994
Definition
An emergency medicine physician who specializes in non-hospital based emergency medical services (e.g., disaster site, accident scene, transport vehicle, etc.) to provide pre-hospital assessment, treatment, and transport patients.
500 HOSPITAL DR, Warrenton, VA 20186
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Other Identifiers 6

Medicaid010055601VA
Medicare PIN930020763VA
Medicare PIN930000711VA
Medicare PIN013448F25VA
Medicare UPINB05512
Medicaid006028608VA

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Mr. William J Barker Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

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

4

Medicare enrollment records show William Barker reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Virginia Emergency Medicine Assoicates, Ltd
Same address
Emergency Medical Services
500 HOSPITAL DR, EMERGENCY DEPARTMENT
Warrenton, VA 20186
  • Reassigned Medicare billing, Virginia enrollment
  • 60 clinicians in this Medicare group
NPI 1700988664 (540) 349-0504
Emergency Medicine Associates P.A., P.C.
12 mi
Emergency Medicine
15225 HEATHCOTE BLVD
Haymarket, VA 20169
  • Reassigned Medicare billing, Virginia and District of Columbia enrollments
  • Also billed through NPI 1063377315 (District of Columbia)
  • 1,294 clinicians in this Medicare group
NPI 1912862244 (330) 493-4443
Fair Oaks Emergency Physicians, PLLC
26 mi
Emergency Medical Services
3600 JOSEPH SIEWICK DR
Fairfax, VA 22033
  • Reassigned Medicare billing, District of Columbia enrollment
  • 71 clinicians in this Medicare group
NPI 1649203605 (703) 391-3996
Inova Health Care Services
32 mi
Urgent Care
100 MAPLE AVE E
Vienna, VA 22180
  • Reassigned Medicare billing, Virginia and District of Columbia enrollments
  • Also billed through NPI 1669511051 (District of Columbia)
  • 2,379 clinicians in this Medicare group
NPI 1275886418 (703) 938-5300

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 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.
85 services84 patients
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.
71 services71 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.
41 services41 patients
Emergency department visit with low level of medical decision making 99283
An emergency department visit for a problem of moderate severity involves immediate medical attention for issues like minor fractures, burns, or high fever. The healthcare team will assess your condition, provide necessary treatment, and may suggest further tests or admission if required.
14 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 20186 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
$86.88 typical visit price
range $56.19 – $170.30
Typical copayment $21.72 (range $14.04 – $42.57)
Most-billed visit code 99203
Established Patient
$99.13 typical visit price
range $18.07 – $138.91
Typical copayment $24.78 (range $4.51 – $34.72)
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.

DR. ALEXANDER-NICHOLAS DESIERTO SUTINGCO MD FACEP
Emergency Medicine (Emergency Medical Services)
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 349-0595
NANDINI CHHITWAL MD
Internal Medicine (Rheumatology)
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 316-5940
DR. JOSEPH G SERVIDEO MD
Emergency Medicine (Emergency Medical Services)
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 349-0595
MELISSA BRAUN NP
Nurse Practitioner (Neonatal)
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 316-4023
MARIA ELENA AQUINO DWYER PT
Physical Therapist
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 316-2680
CHRISTINE SNELL MD
Emergency Medicine (Emergency Medical Services)
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 349-0595
MR. JOSEPH CHU MD
Emergency Medicine (Emergency Medical Services)
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 349-0595
DAVID C REILLY M.D.
Radiology (Diagnostic Radiology)
500 HOSPITAL DR
WARRENTON, VA 20186
Fauquier County (540) 316-5000

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 William Barker's NPI number?

The NPI number for William Barker is 1770599847. It was assigned to this individual provider in the NPPES registry on July 31, 2006.

Where is William Barker located?

William Barker practices at 500 Hospital Dr, Warrenton, VA 20186. The listed phone number is (540) 349-0595.

What is William Barker's specialty?

The primary specialty registered for this NPI is Emergency Medicine, specializing in Emergency Medical Services, with taxonomy code 207PE0004X.

Is William Barker enrolled in Medicare?

Yes. William Barker is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for William Barker's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Barker reassigns Medicare benefits to 4 organizations: Virginia Emergency Medicine Assoicates, Ltd (Warrenton, VA), Emergency Medicine Associates P.A., P.C. (Haymarket, VA), Fair Oaks Emergency Physicians, PLLC (Fairfax, VA) and Inova Health Care Services (Vienna, VA). 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 William Barker's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for William Barker was last updated on April 30, 2008. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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.