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Diagnostic Radiology

Katherine J. To'O, MD

Works at hospitals in Stanford, CA · Pleasanton, CA · California

Summary

Dr. Katherine J. To'O, MD is a radiologist at 300 Pasteur Dr, Stanford, CA 94305. Phone: (650) 723-4000. Accepts Medicare assignment. NPI 1821128844. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026.

From official Medicare data

This page shows what Medicare's official clinician data says about Katherine J. To'O, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Katherine J. To'O accept Medicare assignment?
Yes. Medicare's clinician data says Katherine J. To'O accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
What is Katherine J. To'O's NPI number?
1821128844. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Katherine J. To'O works

Medicare's Facility Affiliation Data lists Katherine J. To'O at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

  • Stanford Health CareStanford, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050441
  • Stanford Health Care Tri-ValleyPleasanton, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050283

Practice locations

Addresses where Katherine J. To'O is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Katherine J. To'O as a member of this group (CMS data updated October 2, 2026).

  • Stanford Health Care3,122 clinicians in the group

Specialties

Find other Diagnostic Radiology doctors in California →

Other radiologists in Stanford

Clinicians with the same Medicare primary specialty in Stanford, CA — not a recommendation.

All radiologists in Stanford →

Other clinicians in Stanford Health Care

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialMD
Graduation year2005 (21 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1821128844
CorrectionsReport an error or suggest an update →

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
  2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
  3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  4. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  5. Medicare Care Compare — official Medicare tool to look up clinicians