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DR. ARASH MAHAJERIN M.D.
NPI 1033315247
Pediatrics - Pediatric Hematology-Oncology in Orange, CA

Active since June 25, 2007PECOS Enrolled
101 THE CITY DR S BLDG 23, ORANGE, CA 92868(714) 456-8000 Get Directions Write a Review

NPPES record last updated: March 14, 2023. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Dr. Arash Mahajerin M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. ARASH MAHAJERIN M.D. (NPI 1033315247) is an individual pediatric hematology-oncology provider in Orange, California, licensed in California (A126238) and active in the NPI registry since June 2007. He is enrolled in Medicare PECOS and maintains a secondary practice location in Orange.

NPPES Registry Identity

NPI1033315247
Entity TypeIndividualMale
Primary Taxonomy2080P0207X
Provider Legal NameDR. ARASH MAHAJERINCredential: M.D.
Location Address101 THE CITY DR S BLDG 23Orange, CA 92868-3201
Mailing Address200 S Manchester Ave Ste 300Orange, CA 92868-3219 · (714) 456-2986
Phone(714) 456-8000
Sole ProprietorNo
Enumeration DateJune 25, 2007
Last NPPES UpdateMarch 14, 2023
NPPES CertifiedMarch 14, 2023
✔ NPI 1033315247 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPediatrics · Pediatric Hematology-OncologyAllopathic & Osteopathic Physicians
Taxonomy Code2080P0207X
License✔ Licensed in CA · A126238
Definition
A pediatrician trained in the combination of pediatrics, hematology and oncology to recognize and manage pediatric blood disorders and cancerous diseases.
101 THE CITY DR S BLDG 23, Orange, CA 92868
Open in Google Maps ↗

Secondary Practice Location 1

Location 11201 W La Veta Ave, Division of HematologyOrange, CA 92868-4203 · Phone (714) 532-8459 · Fax (714) 532-8771

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Arash Mahajerin M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

3

Medicare enrollment records show Arash Mahajerin reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Uc Regents Uci Dept Of Pediatrics
Same address
Pediatrics
101 THE CITY DR S
Orange, CA 92868
  • Reassigned Medicare billing, California enrollment
  • 143 clinicians in this Medicare group
NPI 1235187311 (714) 456-8068
Children's Hospital Of Orange County
1.5 mi
Pediatrics
1201 W LA VETA AVE
Orange, CA 92868
  • Reassigned Medicare billing, California enrollment
  • Medicare enrollment name: Childrens Hospital Of Orange County
  • 190 clinicians in this Medicare group
NPI 1275975104 (714) 509-8649
Center For Comprehensive Care & Diagnosis Of Inherited Blood Disorders
2.0 mi
Clinic/Center
701 S PARKER ST STE 1000
Orange, CA 92868
  • Reassigned Medicare billing, California enrollment
  • 9 clinicians in this Medicare group
NPI 1679875942 (714) 221-1200

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. ZAHRA SADAT HAMEDI MD
Internal Medicine (Hematology & Oncology)
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (714) 456-7890
JULIE SMITH NP
Internal Medicine (Hematology & Oncology)
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (714) 456-8000
HEEKYUNG KIM
Student in an Organized Health Care Education/Training Program
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (949) 819-5969
JINO PARK MD
Radiology (Radiation Oncology)
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (714) 456-5651
REGENTS OF THE UNIVERSITY OF CALIFORNIA
Clinical Medical Laboratory
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (714) 456-5889
DR. ARASH REZAZADEH KALEBASTY M.D.
Internal Medicine (Hematology & Oncology)
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (714) 456-8000
DR. MELISSA LING MAO MD
Surgery (Surgical Oncology)
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (714) 456-8000
DR. MARK E LINSKEY MD
Neurological Surgery
101 THE CITY DR S BLDG 23
ORANGE, CA 92868
Orange County (714) 456-8000

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Arash Mahajerin's NPI number?

The NPI number for Arash Mahajerin is 1033315247. It was assigned to this individual provider in the NPPES registry on June 25, 2007.

Where is Arash Mahajerin located?

Arash Mahajerin practices at 101 The City Dr S Bldg 23, Orange, CA 92868. The listed phone number is (714) 456-8000.

What is Arash Mahajerin's specialty?

The primary specialty registered for this NPI is Pediatrics, specializing in Pediatric Hematology-Oncology, with taxonomy code 2080P0207X.

Is Arash Mahajerin enrolled in Medicare?

Yes. Arash Mahajerin is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Arash Mahajerin's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Arash Mahajerin reassigns Medicare benefits to 3 organizations: Uc Regents Uci Dept Of Pediatrics (Orange, CA), Children's Hospital Of Orange County (Orange, CA) and Center For Comprehensive Care & Diagnosis Of Inherited Blood Disorders (Orange, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Arash Mahajerin's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Arash Mahajerin was last updated on March 14, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.