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DR. KAREN HEATHER KOSER MD
NPI 1861703787
Pediatrics - Developmental - Behavioral Pediatrics in Los Angeles, CA

Active since June 24, 2010PECOS Enrolled
CHILDREN'S HOSPITAL OF LOS ANGELES, 4650 SUNSET BLVD. MS#53, LOS ANGELES, CA 90027(323) 361-3849 Get Directions Write a Review

NPPES record last updated: January 19, 2023. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Jan 19, 2023, Jul 23, 2019, May 16, 2016 (3 updates tracked since 2016).

About Dr. Karen Heather Koser Md NPPES

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

DR. KAREN HEATHER KOSER MD (NPI 1861703787) is an individual developmental - behavioral pediatrics provider in Los Angeles, California, licensed in California (C162529) and active in the NPI registry since June 2010. She is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1861703787
Entity TypeIndividualFemale
Primary Taxonomy2080P0006X
Provider Legal NameDR. KAREN HEATHER KOSERCredential: MD
Location AddressCHILDREN'S HOSPITAL OF LOS ANGELES, 4650 SUNSET BLVD. MS#53Los Angeles, CA 90027
Mailing Address5550 Hollywood Blvd Apt 445Los Angeles, CA 90028-9603
Phone(323) 361-3849
Sole ProprietorNo
Enumeration DateJune 24, 2010
Last NPPES UpdateJanuary 19, 20233 updates tracked since enumeration
✔ NPI 1861703787 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyPediatrics · Developmental - Behavioral PediatricsAllopathic & Osteopathic Physicians
Taxonomy Code2080P0006X
License✔ Licensed in CA · C162529
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 264944 (NY)
CHILDREN'S HOSPITAL OF LOS ANGELES, Los Angeles, CA 90027
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Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Karen Heather Koser Md 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 Karen Koser reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Southern California Permanente Medical Group
1.7 mi
Clinical Medical Laboratory
4580 ELECTRONICS PL
Los Angeles, CA 90039
  • Reassigned Medicare billing, California enrollment
  • 13,921 clinicians in this Medicare group
NPI 1346328853 (818) 502-5940
Children's Hospital Los Angeles Medical Group, Inc.
2.0 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
Nyu Langone Hospitals
2,451 mi
Multi-Specialty
150 55TH ST
Brooklyn, NY 11220
  • Reassigned Medicare billing, New York enrollment
  • 616 clinicians in this Medicare group
NPI 1831549559 (718) 630-7000

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

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 Karen Koser's NPI number?

The NPI number for Karen Koser is 1861703787. It was assigned to this individual provider in the NPPES registry on June 24, 2010.

Where is Karen Koser located?

Karen Koser practices at Children's Hospital Of Los Angeles 4650 Sunset Blvd. Ms#53, Los Angeles, CA 90027. The listed phone number is (323) 361-3849.

What is Karen Koser's specialty?

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

Is Karen Koser enrolled in Medicare?

Yes. Karen Koser is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Karen Koser's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Karen Koser reassigns Medicare benefits to 3 organizations: Southern California Permanente Medical Group (Los Angeles, CA), Children's Hospital Los Angeles Medical Group, Inc. (Los Angeles, CA) and Nyu Langone Hospitals (Brooklyn, NY). 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 Karen Koser'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 Karen Koser was last updated on January 19, 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.