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Internal Medicine

Sara A. Sirajuddin, MD

Works at hospitals in Fontana, CA · California

Summary

Dr. Sara A. Sirajuddin, MD is an internal medicine doctor at 2295 S Vineyard Ave, Ontario, CA 91761. Phone: (909) 724-5000. Accepts Medicare assignment. NPI 1568706059. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026.

  • Specialty: Internal medicine doctor (Medicare lists Internal Medicine)
  • Address: 2295 S Vineyard Ave, Ontario, CA 91761 · Directions (1 more location)
  • Phone: (909) 724‑5000
  • Medicare: Accepts Medicare assignment
  • Hospital: Kaiser Foundation Hospital Fontana/Ontario
  • Group practice: Southern California Permanente Medical Group
  • Medical school: graduated 2012 (14 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Sara A. Sirajuddin, 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 Sara A. Sirajuddin accept Medicare assignment?
Yes. Medicare's clinician data says Sara A. Sirajuddin 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 Sara A. Sirajuddin's NPI number?
1568706059. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Sara A. Sirajuddin works

Medicare's Facility Affiliation Data lists Sara A. Sirajuddin 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.

Practice locations

Addresses where Sara A. Sirajuddin is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Sara A. Sirajuddin as a member of this group (CMS data updated October 2, 2026).

  • Southern California Permanente Medical Group11,293 clinicians in the group

Specialties

Find other Internal Medicine doctors in California →

Other internal medicine doctors in Ontario

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

All internal medicine doctors in Ontario →

Other clinicians in Southern California Permanente Medical Group

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

Clinician information

CredentialMD
Graduation year2012 (14 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1568706059
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