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MRS. MARA SUSAN WILLIAMS
NPI 1861544249
Nurse Practitioner - Adult Health in Napa, CA

Active since January 17, 2007Opted out of Medicare · through Apr 1, 2028
3417 VALLE VERDE DR, NAPA, CA 94558(707) 255-4172(707) 255-2605 Get Directions Write a Review

NPPES record last updated: March 7, 2023. Verified against the NPPES registry weekly; last sync: July 26, 2026.

About Mrs. Mara Susan Williams NPPES

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

MRS. MARA SUSAN WILLIAMS (NPI 1861544249) is an individual adult health provider in Napa, California, licensed in California (345522) and active in the NPI registry since January 2007. She has opted out of Medicare through April 1, 2028 and remains eligible to order and refer.

NPPES Registry Identity

NPI1861544249
Entity TypeIndividualFemale
Primary Taxonomy363LA2200X
Provider Legal NameMRS. MARA SUSAN WILLIAMS
Location Address3417 VALLE VERDE DRNapa, CA 94558-2414
Mailing Address19337 Orange AveSonoma, CA 95476-6215 · (707) 996-6219
Phone(707) 255-4172
Fax(707) 255-2605
Sole ProprietorNo
Enumeration DateJanuary 17, 2007
Last NPPES UpdateMarch 7, 2023
✔ NPI 1861544249 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyNurse Practitioner · Adult HealthPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363LA2200X
License✔ Licensed in CA · 345522
3417 VALLE VERDE DR, Napa, CA 94558
Open in Google Maps ↗

Other Names 1

Former Name (1)Martha Block, Donnelly, Palmer Anp

Other Identifiers 3

Other15902CA · Np Furnishing Number
Other15902CA · Np Certificate Number
Other345522CA · Rn License

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

ⓘ

Opted out of Medicare

Mrs. Mara Susan Williams has filed a Medicare opt-out affidavit. Services are provided under private contract between the provider and the patient, and are not billed to or reimbursed by Medicare. The opt-out is on file from April 1, 2016 through April 1, 2028.

Opt-Out Effective DateApril 1, 2016
Opt-Out In Effect ThroughApril 1, 2028Opt-out affidavits renew automatically every two years unless cancelled
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesAn opted-out provider can still order and refer for Medicare patients in the categories marked above, even though their own services are not covered.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94558 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
$98.97 typical visit price
range $65.08 – $192.16
Typical copayment $24.74 (range $16.27 – $48.04)
Most-billed visit code 99203
Established Patient
$113.15 typical visit price
range $21.86 – $157.83
Typical copayment $28.28 (range $5.46 – $39.45)
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 7

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

LELAND R. RAYMOND MD A PROFESSIONAL CORP
Surgery
3417 VALLE VERDE DR
NAPA, CA 94558
Napa County (707) 259-0339
DR. VICTORIA SCHWARTZ-EDMISTEN DC
Chiropractor
3417 VALLE VERDE DR
NAPA, CA 94558
Napa County (916) 216-5447
ELLEN LOUISE SEGALE
Nutritionist (Nutrition, Education)
3417 VALLE VERDE DR
NAPA, CA 94558
Napa County (707) 255-4172
SUSAN C CISLO D.O.
Neuromusculoskeletal Medicine & OMM
3417 VALLE VERDE DR
NAPA, CA 94558
Napa County (707) 255-4172
BAY AREA OSTEOPATHIC, INC.
Clinic/Center (Medical Specialty)
3417 VALLE VERDE DR
NAPA, CA 94558
Napa County (707) 255-4172
PHOENIX WELLNESS GROUP
Internal Medicine
3417 VALLE VERDE DR
NAPA, CA 94558
Napa County (707) 255-4172
KATHRYN WHISTON-LEMM N.P.
Nurse Practitioner (Acute Care)
3417 VALLE VERDE DR
NAPA, CA 94558
Napa County (707) 226-1246

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 Mara Williams's NPI number?

The NPI number for Mara Williams is 1861544249. It was assigned to this individual provider in the NPPES registry on January 17, 2007. The provider is also known as Martha Block, Donnelly, Palmer Anp.

Where is Mara Williams located?

Mara Williams practices at 3417 Valle Verde Dr, Napa, CA 94558. The listed phone number is (707) 255-4172.

What is Mara Williams's specialty?

The primary specialty registered for this NPI is Nurse Practitioner, specializing in Adult Health, with taxonomy code 363LA2200X.

Is Mara Williams enrolled in Medicare?

No. Mara Williams has opted out of Medicare through April 1, 2028. Care is provided under private contracts, and Medicare does not pay for services furnished by providers who have opted out. The provider remains eligible to order and refer services for Medicare patients.

When was this NPI record last updated?

The NPPES record for Mara Williams was last updated on March 7, 2023. NPI Profile syncs with the weekly NPPES data releases published by CMS.