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IRENE KOOLWIJK M.D.
NPI 1518164706
Pediatrics - Developmental - Behavioral Pediatrics in Los Angeles, CA

Active since June 29, 2007PECOS Enrolled
300 UCLA MEDICAL PLZ STE 3300, LOS ANGELES, CA 90095(310) 825-0867(310) 206-4855 Get Directions Write a Review

NPPES record last updated: April 26, 2021. Verified against the NPPES registry weekly; last sync: November 08, 2026.

Record update history: Apr 26, 2021, Apr 19, 2021, Feb 17, 2021 (3 updates tracked since 2021).

About Irene Koolwijk M.d. NPPES

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

IRENE KOOLWIJK M.D. (NPI 1518164706) is an individual developmental - behavioral pediatrics provider in Los Angeles, California, licensed in California (A121627) and active in the NPI registry since June 2007. She is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1518164706
Entity TypeIndividualFemale
Primary Taxonomy2080P0006X
Provider Legal NameIRENE KOOLWIJKCredential: M.D.
Location Address300 UCLA MEDICAL PLZ STE 3300Los Angeles, CA 90095-6062
Mailing Address5767 W Century Blvd Ste 400Los Angeles, CA 90045-5631 · (310) 301-8707 · Fax (310) 301-8751
Phone(310) 825-0867
Fax(310) 206-4855
Sole ProprietorNo
Enumeration DateJune 29, 2007
Last NPPES UpdateApril 26, 20213 updates tracked since enumeration
NPPES CertifiedApril 26, 2021
✔ NPI 1518164706 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyPediatrics · Developmental - Behavioral PediatricsAllopathic & Osteopathic Physicians
Taxonomy Code2080P0006X
License✔ Licensed in CA · A121627
Definition
A developmental-behavioral specialist is a pediatrician with special training and experience who aims to foster understanding and promotion of optimal development of children and families through research, education, clinical care and advocacy efforts. This physician assists in the prevention, diagnosis, and management of developmental difficulties and problematic behaviors in children and in the family dysfunctions that compromise children's development.
Also ListedPediatricsTaxonomy 208000000X · License A121627 (CA)
Also ListedPediatrics · Neurodevelopmental DisabilitiesTaxonomy 2080P0008X · License A121627 (CA)
300 UCLA MEDICAL PLZ STE 3300, Los Angeles, CA 90095
Open in Google Maps ↗

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Irene Koolwijk 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

2

Medicare enrollment records show Irene Koolwijk reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Uc Regents
0.5 mi
Pediatrics
200 UCLA MEDICAL PLAZA, SUITE 265
Los Angeles, CA 90095
  • Reassigned Medicare billing, California enrollment
  • 323 clinicians in this Medicare group
NPI 1982667663 (310) 825-0867
Children's Hospital Los Angeles Medical Group, Inc.
9.0 mi
Multi-Specialty
4650 SUNSET BLVD
Los Angeles, CA 90027
  • Reassigned Medicare billing, California enrollment
  • Medicare enrollment name: Childrens Hospital Los Angeles Medical Group Inc
  • 1,281 clinicians in this Medicare group
NPI 1265530653 (323) 361-2337

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 8

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

KELSEY STILES PHD
Psychologist (Clinical)
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (310) 794-4941
ROBYN WESTBROOK PH.D.
Psychologist (Clinical)
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (310) 825-0867
DR. SAMANTHA KUCAJ
Psychologist (Clinical Child & Adolescent)
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (323) 825-0867
DAYNA MARIE LANDRY MS, MPH, RD
Dietitian, Registered
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (310) 825-9436
DR. SANCHI MALHOTRA MD
Pediatrics
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (310) 825-0867
DR. SAI NANDINI IYER M.D.
Pediatrics (Developmental - Behavioral Pediatrics)
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (310) 267-6810
DR. MADISON BROOKE HARRIS OTD, MA, OTRL
Psychiatry & Neurology (Neurology with Special Qualifications in Child Neurology)
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (310) 825-0867
GIA CHODZEN
Psychologist
300 UCLA MEDICAL PLZ STE 3300
LOS ANGELES, CA 90095
Los Angeles County (310) 794-4941

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 Irene Koolwijk's NPI number?

The NPI number for Irene Koolwijk is 1518164706. It was assigned to this individual provider in the NPPES registry on June 29, 2007.

Where is Irene Koolwijk located?

Irene Koolwijk practices at 300 Ucla Medical Plz Ste 3300, Los Angeles, CA 90095. The listed phone number is (310) 825-0867.

What is Irene Koolwijk's specialty?

The primary specialty registered for this NPI is Pediatrics, specializing in Developmental - Behavioral Pediatrics, with taxonomy code 2080P0006X.

Is Irene Koolwijk enrolled in Medicare?

Yes. Irene Koolwijk is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Irene Koolwijk's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Irene Koolwijk reassigns Medicare benefits to 2 organizations: Uc Regents (Los Angeles, CA) and Children's Hospital Los Angeles Medical Group, Inc. (Los Angeles, 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 Irene Koolwijk'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 Irene Koolwijk was last updated on April 26, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 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.