Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Allergy/Immunology

Ellen D. Stephen, MD

Sees patients in Modesto, CA · California

Summary

Ellen D. Stephen, MD (Allergy/Immunology) is enrolled with Medicare at 1 practice location in Modesto, CA. NPI 1225521776. Medicare data says the clinician accepts Medicare assignment. Source: CMS National Downloadable File, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Ellen D. Stephen, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

Allergy/ImmunologyPrimary specialty
YesAccepts Medicare assignment
8Years since medical school (graduated 2018)
FemaleGender (as listed)
Permanente Medical Group IncGroup practice

Quick answers

Where does Ellen D. Stephen see patients?
Medicare's clinician data lists 1 practice location in Modesto, CA. Call before your visit to confirm the address.
What is Ellen D. Stephen's specialty?
Medicare lists Allergy/Immunology as the primary specialty.
Does Ellen D. Stephen accept Medicare assignment?
Yes. Medicare's clinician data says Ellen D. Stephen accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
What is the phone number for Ellen D. Stephen?
(209) 735-5000, as listed in official Medicare / NPI Registry data.
What is Ellen D. Stephen's NPI number?
1225521776. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Practice locations

Addresses where Ellen D. Stephen is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Ellen D. Stephen as a member of this group (CMS data updated 2026-10-02).

  • Permanente Medical Group Inc10,996 clinicians in the group

Specialties

Find other Allergy/Immunology doctors in California →

Other allergist and immunologists in California

Clinicians with the same Medicare primary specialty in California — not a recommendation.

All allergist and immunologists in California →

Clinician information

CredentialMD
Graduation year2018
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1225521776
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. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  2. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  3. Medicare Care Compare — official Medicare tool to look up clinicians