1. Home
  2. Directory
  3. California
  4. Stanford
  5. Internal Medicine
  6. NPI Profile
Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

IRENA TUNG-NING TAN MD
NPI 1427411826
Internal Medicine - Medical Oncology in Stanford, CA

Active since April 01, 2016PECOS Enrolled
300 PASTEUR DR, STANFORD, CA 94305(650) 723-4000 Get Directions Write a Review

NPPES record last updated: October 27, 2026. Verified against the NPPES registry weekly; last sync: November 08, 2026.

Record update history: Oct 27, 2026, Jul 19, 2021, Apr 1, 2016 (3 updates tracked since 2016).

About Irena Tung-ning Tan Md NPPES

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

IRENA TUNG-NING TAN MD (NPI 1427411826) is an individual medical oncology provider in Stanford, California, licensed in California (A160622) and active in the NPI registry since April 2016. She is enrolled in Medicare PECOS and maintains a secondary practice location in Palo Alto.

NPPES Registry Identity

NPI1427411826
Entity TypeIndividualFemale
Primary Taxonomy207RX0202X
Provider Legal NameIRENA TUNG-NING TANCredential: MD
Location Address300 PASTEUR DRStanford, CA 94305-2200
Mailing Address300 Pasteur DrStanford, CA 94305-2200 · (650) 723-4000
Phone(650) 723-4000
Sole ProprietorNo
Enumeration DateApril 1, 2016
Last NPPES UpdateOctober 27, 20263 updates tracked since enumeration
NPPES CertifiedOctober 27, 2026
✔ NPI 1427411826 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyInternal Medicine · Medical OncologyAllopathic & Osteopathic Physicians
Taxonomy Code207RX0202X
License✔ Licensed in CA · A160622
Definition
An internist who specializes in the diagnosis and treatment of all types of cancer and other benign and malignant tumors. This specialist decides on and administers therapy for these malignancies as well as consults with surgeons and radiotherapists on other treatments for cancer.
Also ListedInternal MedicineTaxonomy 207R00000X · License A160622 (CA)
Also ListedInternal Medicine · HematologyTaxonomy 207RH0000X · License A160622 (CA)
300 PASTEUR DR, Stanford, CA 94305
Open in Google Maps ↗

Secondary Practice Location 1

Location 1875 Blake Wilbur DrPalo Alto, CA 94304-2205 · Phone (650) 498-6000

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Irena Tung-ning Tan Md 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.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94305 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
$206.04 typical visit price
range $70.37 – $206.04
Typical copayment $51.51 (range $17.59 – $51.51)
Most-billed visit code 99205
Established Patient
$121.77 typical visit price
range $23.96 – $169.60
Typical copayment $30.44 (range $5.99 – $42.40)
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.

PRISTA CHARUWORN MD
Internal Medicine (Gastroenterology)
300 PASTEUR DR, ALWAY BUILD M211, MC 5187
STANFORD, CA 94305
Santa Clara County (650) 723-6661
ANDREW CHARLES PICEL M.D
Radiology (Vascular & Interventional Radiology)
300 PASTEUR DR
STANFORD, CA 94305
Santa Clara County (650) 723-4000
MATTHEW A WRIGHT M.D. PH.D.
Psychiatry & Neurology (Psychiatry)
300 PASTEUR DR
STANFORD, CA 94305
Santa Clara County (650) 723-4000
DR. QUAZI ZUBAIR AL-TARIQ M.D.
Radiology (Diagnostic Radiology)
300 PASTEUR DR
STANFORD, CA 94305
Santa Clara County (650) 723-4000
ANGIE DEE MURKINS NP
Nurse Practitioner
300 PASTEUR DR
STANFORD, CA 94305
Santa Clara County (650) 723-4000
DR. JAMSHID GHAJAR MD PHD
Neurological Surgery
300 PASTEUR DR
STANFORD, CA 94305
Santa Clara County (650) 723-4000
SARA BAKHTARY M.D.
Pathology (Anatomic Pathology & Clinical Pathology)
300 PASTEUR DR, LANE 235
STANFORD, CA 94305
Santa Clara County (650) 723-5252
YU KUANG LAI MD
Internal Medicine (Critical Care Medicine)
300 PASTEUR DR
STANFORD, CA 94305
Santa Clara County (650) 723-4000

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 Irena Tan's NPI number?

The NPI number for Irena Tan is 1427411826. It was assigned to this individual provider in the NPPES registry on April 1, 2016.

Where is Irena Tan located?

Irena Tan practices at 300 Pasteur Dr, Stanford, CA 94305. The listed phone number is (650) 723-4000.

What is Irena Tan's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Medical Oncology, with taxonomy code 207RX0202X.

Is Irena Tan enrolled in Medicare?

Yes. Irena Tan is registered in the Medicare PECOS enrollment system.

When was this NPI record last updated?

The NPPES record for Irena Tan was last updated on October 27, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 days 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.