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

Hematology/Oncology

Susan M. O Brien, MD

Works at hospitals in Rancho Mirage, CA · Orange, CA · California

Summary

Susan M. O Brien, MD (Hematology/Oncology) is listed by Medicare at 2 hospitals in Rancho Mirage, CA and Orange, CA. NPI 1669577276. Medicare data says the clinician accepts Medicare assignment. Source: CMS Facility Affiliation Data, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Susan M. O Brien, 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

Hematology/OncologyPrimary specialty
YesAccepts Medicare assignment
YesOffers telehealth
46Years since medical school (graduated 1980)
FemaleGender (as listed)
UC RegentsGroup practice

Quick answers

Which hospitals does Susan M. O Brien work at?
Medicare's official clinician data lists Susan M. O Brien at 2 hospitals: Eisenhower Medical Center and UCI Health-Orange. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Susan M. O Brien see patients?
Medicare's clinician data lists 1 practice location in Orange, CA. Call before your visit to confirm the address.
What is Susan M. O Brien's specialty?
Medicare lists Hematology/Oncology as the primary specialty, and also Internal Medicine.
Does Susan M. O Brien accept Medicare assignment?
Yes. Medicare's clinician data says Susan M. O Brien 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.
Does Susan M. O Brien offer telehealth?
Medicare's clinician data says Susan M. O Brien offers telehealth services. Ask the office which visits can be done by video or phone.
What is the phone number for Susan M. O Brien?
(714) 456-7004, as listed in official Medicare / NPI Registry data.
What is Susan M. O Brien's NPI number?
1669577276. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Susan M. O Brien works

Medicare's Facility Affiliation Data lists Susan M. O Brien at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.

Practice locations

Addresses where Susan M. O Brien is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Susan M. O Brien as a member of this group (CMS data updated 2026-10-02).

  • 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 →

Clinician information

CredentialMD
Graduation year1980
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
TelehealthOffers telehealth services
NPI (National Provider Identifier)1669577276
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 2026-10-02, retrieved 2026-10-29
  2. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians