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Hematology/Oncology

Nellie N. Nafissi, MD

Works at hospitals in Orange, CA · California

Summary

Dr. Nellie N. Nafissi, MD is a hematologist-oncologist at 101 The City Dr S, Orange, CA 92868. Phone: (714) 456-7002. Accepts Medicare assignment. NPI 1821523937. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026.

  • Specialty: Hematologist-oncologist (Medicare lists Hematology/Oncology)
  • Address: 101 The City Dr S, Orange, CA 92868 · Directions
  • Phone: (714) 456‑7002
  • Medicare: Accepts Medicare assignment
  • Hospital: UCI Health-Orange
  • Group practice: UC Regents
  • Medical school: graduated 2017 (9 years since medical school)
  • Gender (as listed): Female
  • Telehealth: offered

From official Medicare data

This page shows what Medicare's official clinician data says about Nellie N. Nafissi, 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 Nellie N. Nafissi accept Medicare assignment?
Yes. Medicare's clinician data says Nellie N. Nafissi 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 Nellie N. Nafissi's NPI number?
1821523937. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Nellie N. Nafissi works

Medicare's Facility Affiliation Data lists Nellie N. Nafissi 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.

  • UCI Health-OrangeOrange, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050348

Practice locations

Addresses where Nellie N. Nafissi is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Nellie N. Nafissi as a member of this group (CMS data updated October 2, 2026).

  • UC Regents319 clinicians in the group

Specialties

Find other Hematology/Oncology doctors in California →

Other hematologist-oncologists in Orange

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

All hematologist-oncologists in Orange →

Other clinicians in UC Regents

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

Clinician information

CredentialMD
Graduation year2017 (9 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
TelehealthOffers telehealth services
NPI (National Provider Identifier)1821523937
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