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TAMMY ANN WINCHELL A.R.N.P
NPI 1679673347
Nurse Practitioner - Pediatrics in Mill Valley, CA

Active since September 23, 2006PECOS Enrolled
750 REDWOOD HWY FRONTAGE RD STE 1204, MILL VALLEY, CA 94941(415) 384-4778(415) 384-4779 Get Directions Write a Review

NPPES record last updated: June 6, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Jun 6, 2025, May 22, 2025, Mar 10, 2022 and 1 more (4 updates tracked since 2019).

About Tammy Ann Winchell A.r.n.p NPPES

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

TAMMY ANN WINCHELL A.R.N.P (NPI 1679673347) is an individual pediatrics provider in Mill Valley, California, licensed in Washington (AP30007401) and active in the NPI registry since September 2006. She is enrolled in Medicare PECOS and maintains a secondary practice location in Orange.

NPPES Registry Identity

NPI1679673347
Entity TypeIndividualFemale
Primary Taxonomy363LP0200X
Provider Legal NameTAMMY ANN WINCHELLCredential: A.R.N.P
Location Address750 REDWOOD HWY FRONTAGE RD STE 1204Mill Valley, CA 94941-2483
Mailing Address700 Ne 87th Ave Ste 110Vancouver, WA 98664-4896
Phone(415) 384-4778
Fax(415) 384-4779
Sole ProprietorNo
Enumeration DateSeptember 23, 2006
Last NPPES UpdateJune 6, 20254 updates tracked since enumeration
NPPES CertifiedJune 6, 2025
✔ NPI 1679673347 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyNurse Practitioner · PediatricsPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363LP0200X
Licenses✔ Licensed in WA · AP30007401✔ Licensed in CA · NP95000700✔ Licensed in OR · 201150050NP
750 REDWOOD HWY FRONTAGE RD STE 1204, Mill Valley, CA 94941
Open in Google Maps ↗

Other Names 1

Former Name (1)Tammy Ann Herschler

Secondary Practice Location 1

Location 11201 W La Veta AveOrange, CA 92868-4203 · Phone (714) 509-7601 · Fax (714) 509-7650

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Moda Health Plan, Inc..Insurance ›

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Tammy Ann Winchell A.r.n.p 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

3

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

Northwest Acute Care Specialists PC
526 mi
Emergency Medicine
101 SW MAIN ST STE 940
Portland, OR 97204
  • Reassigned Medicare billing, Oregon and Washington enrollments
  • 163 clinicians in this Medicare group
NPI 1215983200 (503) 464-9034
Legacy Emanuel Hospital & Health Center
527 mi
General Acute Care Hospital
1225 NE 2ND AVE
Portland, OR 97232
  • Reassigned Medicare billing, Oregon enrollment
  • 719 clinicians in this Medicare group
NPI 1003367491 (503) 944-8000
The Vancouver Clinic Inc Ps
534 mi
Internal Medicine
700 NE 87TH AVE
Vancouver, WA 98664
  • Reassigned Medicare billing, Washington enrollment
  • 711 clinicians in this Medicare group
NPI 1992759427 (360) 882-2778

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94941 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
$104.67 typical visit price
range $69.07 – $202.63
Typical copayment $26.16 (range $17.26 – $50.65)
Most-billed visit code 99203
Established Patient
$119.61 typical visit price
range $23.44 – $166.64
Typical copayment $29.90 (range $5.86 – $41.66)
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 6

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

DR. JOHN W ELLIOTT MD
Emergency Medicine
750 REDWOOD HWY FRONTAGE RD STE 1204
MILL VALLEY, CA 94941
Marin County (415) 384-4778
ALEXIS A MARTINEZ PA-C
Physician Assistant
750 REDWOOD HWY FRONTAGE RD STE 1204
MILL VALLEY, CA 94941
Marin County (415) 384-4778
SARAH ALLPHIN HUBBELL DNP, FNP-C
Nurse Practitioner (Family)
750 REDWOOD HWY FRONTAGE RD STE 1204
MILL VALLEY, CA 94941
Marin County (415) 384-4778
ARON R BAUM PA-C
Physician Assistant
750 REDWOOD HWY FRONTAGE RD STE 1204
MILL VALLEY, CA 94941
Marin County (415) 384-4778
JASON JUSTIN PA-C
Physician Assistant
750 REDWOOD HWY FRONTAGE RD STE 1204
MILL VALLEY, CA 94941
Marin County (415) 384-4778
LAURA SASSO PA-C
Physician Assistant (Medical)
750 REDWOOD HWY FRONTAGE RD STE 1204
MILL VALLEY, CA 94941
Marin County (415) 384-4778

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 Tammy Winchell's NPI number?

The NPI number for Tammy Winchell is 1679673347. It was assigned to this individual provider in the NPPES registry on September 23, 2006. The provider is also known as Tammy Ann Herschler.

Where is Tammy Winchell located?

Tammy Winchell practices at 750 Redwood Hwy Frontage Rd Ste 1204, Mill Valley, CA 94941. The listed phone number is (415) 384-4778.

What is Tammy Winchell's specialty?

The primary specialty registered for this NPI is Nurse Practitioner, specializing in Pediatrics, with taxonomy code 363LP0200X.

Is Tammy Winchell enrolled in Medicare?

Yes. Tammy Winchell is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Tammy Winchell's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Tammy Winchell reassigns Medicare benefits to 3 organizations: Northwest Acute Care Specialists PC (Portland, OR), Legacy Emanuel Hospital & Health Center (Portland, OR) and The Vancouver Clinic Inc Ps (Vancouver, WA). 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 Tammy Winchell's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Tammy Winchell accept?

Health plans from Moda Health Plan, Inc. list Tammy Winchell 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.

When was this NPI record last updated?

The NPPES record for Tammy Winchell was last updated on June 6, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 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.