DR. GREGORY LEE THALKEN MD
NPI 1861547317
Radiology - Diagnostic Radiology in Long Beach, CA
About Dr. Gregory Lee Thalken Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. GREGORY LEE THALKEN MD (NPI 1861547317) is an individual diagnostic radiology provider in Long Beach, California, licensed in California (C162624) and active in the NPI registry since January 2007. He is enrolled in Medicare PECOS, is affiliated with Norman Regional, and maintains 8 additional practice locations.
NPPES Registry Identity
Specialties & Licenses
Secondary Practice Locations 8
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Dr. Gregory Lee Thalken Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
82Medicare enrollment records show Gregory Thalken reassigns Medicare billing to 82 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Long Beach, CA 90813
- Reassigned Medicare billing, California enrollment
- 1,939 clinicians in this Medicare group
Los Alamitos, CA 90720
- Reassigned Medicare billing, Minnesota enrollment
- 2 clinicians in this Medicare group
Fountain Valley, CA 92708
- Reassigned Medicare billing, California enrollment
- 948 clinicians in this Medicare group
Anaheim, CA 92807
- Reassigned Medicare billing, California and Minnesota enrollments
- 95 clinicians in this Medicare group
Glendale, CA 91206
- Reassigned Medicare billing, California enrollment
- 678 clinicians in this Medicare group
Monrovia, CA 91016
- Reassigned Medicare billing, Minnesota enrollment
- 2 clinicians in this Medicare group
Glendora, CA 91741
- Reassigned Medicare billing, Minnesota enrollment
- 2 clinicians in this Medicare group
West Hills, CA 91307
- Reassigned Medicare billing, Minnesota enrollment
- 2 clinicians in this Medicare group
Upland, CA 91786
- Reassigned Medicare billing, Minnesota enrollment
- 2 clinicians in this Medicare group
Temecula, CA 92592
- Reassigned Medicare billing, California enrollment
- 124 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Areas of Expertise CMS Part B claims 23
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Norman Regional
Acute Care Hospitals · Norman, OKPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 90806 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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.
LONG BEACH, CA 90806
LONG BEACH, CA 90806
LONG BEACH, CA 90806
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 Gregory Thalken's NPI number?
The NPI number for Gregory Thalken is 1861547317. It was assigned to this individual provider in the NPPES registry on January 24, 2007.
Where is Gregory Thalken located?
Gregory Thalken practices at 2801 Atlantic Ave, Long Beach, CA 90806. The listed phone number is (562) 933-1550.
What is Gregory Thalken's specialty?
The primary specialty registered for this NPI is Radiology, specializing in Diagnostic Radiology, with taxonomy code 2085R0202X.
Is Gregory Thalken enrolled in Medicare?
Yes. Gregory Thalken is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Gregory Thalken's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Gregory Thalken reassigns Medicare benefits to 82 organizations: County Of Los Angeles (Long Beach, CA), Los Alamitos Radiology Group Inc (Los Alamitos, CA), Memorialcare Medical Foundation (Fountain Valley, CA), Fullerton Radiology Medical Group, Inc (Anaheim, CA), Adventist Health Physicians Network (Glendale, CA) and 77 more organizations, listed in the Medicare section above. 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 Gregory Thalken's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Gregory Thalken accept?
Health plans from Ambetter from Arizona Complete Health, Ambetter from Arkansas Health & Wellness, Ambetter from Louisiana Healthcare Connections, Ambetter from Superior HealthPlan and Ambetter of Oklahoma and 16 other insurers list Gregory Thalken as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Gregory Thalken affiliated with any hospitals?
According to CMS data, Gregory Thalken is affiliated with Norman Regional.
When was this NPI record last updated?
The NPPES record for Gregory Thalken was last updated on May 6, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 months 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.
# Dr. Gregory Lee Thalken, MD · NPI 1861547317
Diagnostic Radiology physician in Long Beach, California. Individual provider, active in the CMS NPPES registry since January 24, 2007.
## Identity
- **NPI:** 1861547317 (Entity type: Individual)
- **Enumerated:** January 24, 2007
- **Primary specialty:** Radiology - Diagnostic Radiology · taxonomy 2085R0202X
- **State license:** C162624 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 2801 ATLANTIC AVE, Long Beach, CA 90806-1701
- **Phone:** (562) 933-1550
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 82 organizations under Medicare reassignment (form CMS-855R): County Of Los Angeles (NPI 1568483766, Long Beach, CA); Los Alamitos Radiology Group Inc (NPI 1427005024, Los Alamitos, CA); Memorialcare Medical Foundation (NPI 1205167350, Fountain Valley, CA); Fullerton Radiology Medical Group, Inc (NPI 1861451858, Anaheim, CA); Adventist Health Physicians Network (NPI 1669093357, Glendale, CA); and 77 more · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2006
## Record status
- **NPPES last updated:** May 6, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1861547317) · Data from the CMS NPPES public registry.