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DR. DONALD REX SIMPSON M.D., PH.D.
NPI 1699053397
Specialist in Northridge, CA

Active since July 28, 2011PECOS Enrolled
17425 PARTHENIA ST, NORTHRIDGE, CA 91325(818) 298-1442(818) 775-1176 Get Directions Write a Review

NPPES record last updated: July 28, 2011. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Dr. Donald Rex Simpson M.d., Ph.d. NPPES

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

DR. DONALD REX SIMPSON M.D., PH.D. (NPI 1699053397) is an individual specialist in Northridge, California, licensed in California (G44436) and active in the NPI registry since July 2011. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1699053397
Entity TypeIndividualMale
Primary Taxonomy174400000X
Provider Legal NameDR. DONALD REX SIMPSONCredential: M.D., PH.D.
Location Address17425 PARTHENIA STNorthridge, CA 91325-3240
Mailing Address17425 Parthenia StNorthridge, CA 91325-3240 · (818) 298-1442 · Fax (818) 775-1176
Phone(818) 298-1442
Fax(818) 775-1176
Sole ProprietorNo
Enumeration DateJuly 28, 2011
✔ NPI 1699053397 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtySpecialistOther Service Providers
Taxonomy Code174400000X
License✔ Licensed in CA · G44436
Definition
An individual educated and trained in an applied knowledge discipline used in the performance of work at a level requiring knowledge and skills beyond or apart from that provided by a general education or liberal arts degree.
Also ListedPathology · CytopathologyTaxonomy 207ZC0500X · License G44436 (CA)
Also ListedPathology · Anatomic Pathology & Clinical PathologyTaxonomy 207ZP0102X · License G44436 (CA)
17425 PARTHENIA ST, Northridge, CA 91325
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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. Donald Rex Simpson M.d., Ph.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 Reassignment

Medicare enrollment records show Donald Simpson reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Path MD Inc
59 mi
Clinical Medical Laboratory
181 TECHNOLOGY DR STE 100B
Irvine, CA 92618
  • Reassigned Medicare billing, California enrollment
  • 22 clinicians in this Medicare group
NPI 1124316138 (424) 302-3307

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 Donald Simpson's NPI number?

The NPI number for Donald Simpson is 1699053397. It was assigned to this individual provider in the NPPES registry on July 28, 2011.

Where is Donald Simpson located?

Donald Simpson practices at 17425 Parthenia St, Northridge, CA 91325. The listed phone number is (818) 298-1442.

What is Donald Simpson's specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

Is Donald Simpson enrolled in Medicare?

Yes. Donald Simpson is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Donald Simpson's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Donald Simpson reassigns Medicare benefits to Path MD Inc (Irvine, CA). The 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 Donald Simpson'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 Donald Simpson was last updated on July 28, 2011. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 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.