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ELLEN JANE ZEMARKOWITZ LCSW
NPI 1053252957
Counselor - Mental Health in Palo Alto, CA

Active since April 03, 2026PECOS Enrolled
725 WELCH RD, PALO ALTO, CA 94304(650) 497-8000 Get Directions Write a Review

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

Record update history: Jul 30, 2026, Apr 3, 2026 (2 updates tracked since 2026).

About Ellen Jane Zemarkowitz Lcsw NPPES

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

ELLEN JANE ZEMARKOWITZ LCSW (NPI 1053252957) is an individual mental health provider in Palo Alto, California, licensed in California (89459) and active in the NPI registry since April 2026. She is enrolled in Medicare PECOS and is a graduate of Other (2015).

NPPES Registry Identity

NPI1053252957
Entity TypeIndividualFemale
Primary Taxonomy101YM0800X
Provider Legal NameELLEN JANE ZEMARKOWITZCredential: LCSW
Location Address725 WELCH RDPalo Alto, CA 94304-1601
Mailing Address725 Welch RdPalo Alto, CA 94304-1601 · (650) 497-8000
Phone(650) 497-8000
Sole ProprietorNo
Medical School CMSOtherGraduated 2015
Enumeration DateApril 3, 2026
Last NPPES UpdateJuly 30, 20262 updates tracked since enumeration
NPPES CertifiedJuly 30, 2026
✔ NPI 1053252957 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyCounselor · Mental HealthBehavioral Health & Social Service Providers
Taxonomy Code101YM0800X
License✔ Licensed in CA · 89459
Also ListedSocial Worker · ClinicalTaxonomy 1041C0700X · License LCSW89459 (CA)
725 WELCH RD, Palo Alto, CA 94304
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Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Ellen Jane Zemarkowitz Lcsw is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID6305306697
PECOS Enrollment IDI20260905000563
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 Reassignment

Medicare enrollment records show Ellen Zemarkowitz reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Lpch Medical Group Div Of Lucile
Same address
Children
725 WELCH RD
Palo Alto, CA 94304
  • Reassigned Medicare billing, California enrollment
  • 3,617 clinicians in this Medicare group
NPI 1417907940 (650) 498-6762

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

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.

EIRI INENAGA MS, OTR/L
Occupational Therapist (Pediatrics)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8218
WENDY LEIGH ADAMS ARNP
Nurse Practitioner (Neonatal)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
KEVIN WEI-HAN CHI MD
Pediatrics
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
ASHEEN RAMA MD
Anesthesiology (Pediatric Anesthesiology)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
CRYSTAL LEE MACKALL MD
Pediatrics (Pediatric Hematology-Oncology)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
KRISTI LYNNE O'CONNOR OT
Occupational Therapist
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
LAUREN GENNA ROOS NP
Nurse Practitioner
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
SHALINI MITTAL MD
Hospitalist
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000

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 Ellen Zemarkowitz's NPI number?

The NPI number for Ellen Zemarkowitz is 1053252957. It was assigned to this individual provider in the NPPES registry on April 3, 2026.

Where is Ellen Zemarkowitz located?

Ellen Zemarkowitz practices at 725 Welch Rd, Palo Alto, CA 94304. The listed phone number is (650) 497-8000.

What is Ellen Zemarkowitz's specialty?

The primary specialty registered for this NPI is Counselor, specializing in Mental Health, with taxonomy code 101YM0800X.

Is Ellen Zemarkowitz enrolled in Medicare?

Yes. Ellen Zemarkowitz is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Ellen Zemarkowitz's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Ellen Zemarkowitz reassigns Medicare benefits to Lpch Medical Group Div Of Lucile (Palo Alto, CA). The 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 Ellen Zemarkowitz'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 Ellen Zemarkowitz was last updated on July 30, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.