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MARK E. WILLIAMS MD
NPI 1770661530
Emergency Medicine in Santa Rosa, CA

Active since November 01, 2006PECOS EnrolledAccepts Medicare Assignment
401 BICENTENNIAL WAY, SANTA ROSA, CA 95403(707) 393-4800 Get Directions Write a Review

NPPES record last updated: April 5, 2024. Verified against the NPPES registry weekly; last sync: August 16, 2026.

Record update history: Apr 5, 2024, May 13, 2023, Dec 13, 2021 (3 updates tracked since 2021).

About Mark E. Williams Md NPPES

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

MARK E. WILLIAMS MD (NPI 1770661530) is an individual emergency medicine provider in Santa Rosa, California, licensed in California (A72120) and active in the NPI registry since November 2006. He is enrolled in Medicare PECOS and is a graduate of University Of Michigan Medical School (1996).

NPPES Registry Identity

NPI1770661530
Entity TypeIndividualMale
Primary Taxonomy207P00000X
Provider Legal NameMARK E. WILLIAMSCredential: MD
Location Address401 BICENTENNIAL WAYSanta Rosa, CA 95403-2149
Mailing Address1800 Harrison St Fl 7Oakland, CA 94612-3466 · (510) 625-6262
Phone(707) 393-4800
Sole ProprietorNo
Medical School CMSUniversity Of Michigan Medical SchoolGraduated 1996
Enumeration DateNovember 1, 2006
Last NPPES UpdateApril 5, 20243 updates tracked since enumeration
NPPES CertifiedApril 5, 2024
✔ NPI 1770661530 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyEmergency MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207P00000X
License✔ Licensed in CA · A72120
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.
401 BICENTENNIAL WAY, Santa Rosa, CA 95403
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Other Identifiers 1

Medicaid00A721200CA

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

Mark E. Williams 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 ID8527248731
PECOS Enrollment IDI20240807000308
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.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 95403 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
$96.16 typical visit price
range $63.04 – $187.01
Typical copayment $24.04 (range $15.76 – $46.75)
Most-billed visit code 99203
Established Patient
$109.88 typical visit price
range $21.02 – $153.40
Typical copayment $27.47 (range $5.25 – $38.35)
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.

MS. JESSICA ANNE RUTLAND R.D.
Dietitian, Registered
401 BICENTENNIAL WAY
SANTA ROSA, CA 95403
Sonoma County (707) 393-4787
KURT FALKENBERG P.T.
Physical Therapist
401 BICENTENNIAL WAY, EAST BUILDING, SUITE 190
SANTA ROSA, CA 95403
Sonoma County (707) 571-3352
DELILAH PATTERSON CRNA
Nurse Anesthetist, Certified Registered
401 BICENTENNIAL WAY
SANTA ROSA, CA 95403
Sonoma County (707) 393-4616
KRISZTINA J. BALAZS MD
Pediatrics
401 BICENTENNIAL WAY
SANTA ROSA, CA 95403
Sonoma County (707) 571-4000
JOHN F. KUNKEL MD
Pathology (Anatomic Pathology)
401 BICENTENNIAL WAY
SANTA ROSA, CA 95403
Sonoma County (707) 571-4000
CRISTINA COREY SCHROEN LCSW
Social Worker (Clinical)
401 BICENTENNIAL WAY
SANTA ROSA, CA 95403
Sonoma County (707) 571-2536
JIE GIOK RAHARDJA PHARMD
Pharmacist
401 BICENTENNIAL WAY
SANTA ROSA, CA 95403
Sonoma County (707) 393-4652
CONOR WILLIAM BOWMAN PHARM.D.
Pharmacist
401 BICENTENNIAL WAY
SANTA ROSA, CA 95403
Sonoma County (818) 522-1238

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 Mark Williams's NPI number?

The NPI number for Mark Williams is 1770661530. It was assigned to this individual provider in the NPPES registry on November 1, 2006.

Where is Mark Williams located?

Mark Williams practices at 401 Bicentennial Way, Santa Rosa, CA 95403. The listed phone number is (707) 393-4800.

What is Mark Williams's specialty?

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

Is Mark Williams enrolled in Medicare?

Yes. Mark Williams 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.

When was this NPI record last updated?

The NPPES record for Mark Williams was last updated on April 5, 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.