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THERESA ANN TACY M.D.
NPI 1366478638
Pediatrics - Pediatric Cardiology in Palo Alto, CA

Active since June 25, 2006PECOS EnrolledAccepts Medicare Assignment
725 WELCH RD, PALO ALTO, CA 94304(650) 497-8000 Get Directions Write a Review

NPPES record last updated: April 11, 2024. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Theresa Ann Tacy M.d. NPPES

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

THERESA ANN TACY M.D. (NPI 1366478638) is an individual pediatric cardiology provider in Palo Alto, California, licensed in California (C50143) and active in the NPI registry since June 2006. She is enrolled in Medicare PECOS and is a graduate of Other (1987).

NPPES Registry Identity

NPI1366478638
Entity TypeIndividualFemale
Primary Taxonomy2080P0202X
Provider Legal NameTHERESA ANN TACYCredential: M.D.
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 1987
Enumeration DateJune 25, 2006
Last NPPES UpdateApril 11, 2024
NPPES CertifiedApril 11, 2024
✔ NPI 1366478638 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyPediatrics · Pediatric CardiologyAllopathic & Osteopathic Physicians
Taxonomy Code2080P0202X
License✔ Licensed in CA · C50143
Definition
A pediatric cardiologist provides comprehensive care to patients with cardiovascular problems. This specialist is skilled in selecting, performing and evaluating the structural and functional assessment of the heart and blood vessels, and the clinical evaluation of cardiovascular disease.
Also ListedPediatricsTaxonomy 208000000X · License C50143 (CA)
725 WELCH RD, Palo Alto, CA 94304
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Other Identifiers 1

Medicaid00C501430CA

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Theresa Ann Tacy M.d. 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 ID3577508696
PECOS Enrollment IDI20050620001070
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

2

Medicare enrollment records show Theresa Tacy reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

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
Stanford Health Care
0.2 mi
General Acute Care Hospital
300 PASTEUR DRIVE
Stanford, CA 94305
  • Reassigned Medicare billing, California enrollment
  • 4,258 clinicians in this Medicare group
NPI 1437292927 (650) 723-4000

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 Theresa Tacy's NPI number?

The NPI number for Theresa Tacy is 1366478638. It was assigned to this individual provider in the NPPES registry on June 25, 2006.

Where is Theresa Tacy located?

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

What is Theresa Tacy's specialty?

The primary specialty registered for this NPI is Pediatrics, specializing in Pediatric Cardiology, with taxonomy code 2080P0202X.

Is Theresa Tacy enrolled in Medicare?

Yes. Theresa Tacy 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.

Which organizations bill Medicare for Theresa Tacy's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Theresa Tacy reassigns Medicare benefits to 2 organizations: Lpch Medical Group Div Of Lucile (Palo Alto, CA) and Stanford Health Care (Stanford, CA). 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 Theresa Tacy'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 Theresa Tacy was last updated on April 11, 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.