GASTROENTEROLOGY SPECIALISTS MEDICAL GROUP, INC A MEDICAL CORPORATION
NPI 1629170998
Internal Medicine - Gastroenterology in Castro Valley, CA
About Gastroenterology Specialists Medical Group, Inc A Medical Corporation NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
GASTROENTEROLOGY SPECIALISTS MEDICAL GROUP, INC A MEDICAL CORPORATION (NPI 1629170998), doing business as Gastroenterology Specialists Medical Group, is a healthcare organization registered as a gastroenterology in Castro Valley, California and active in the NPI registry since September 2006. The organization holds a CLIA Certificate of Compliance certificate valid through November 19, 2027 and lists Wei-fang Ko Ko, President, as its authorized official.
NPPES Registry Identity
Specialties & Licenses
Other Names 1
Group Practice 1
Medicare Participation & PECOS CMS
Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Gastroenterology Specialists Medical Group, Inc A Medical Corporation is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Clinicians Billing Medicare Through This Organization
8Medicare enrollment records show 8 clinicians reassign Medicare billing to Gastroenterology Specialists Medical Group, Inc A Medical Corporation, which bills Medicare for the services they deliver. Of these, 4 practice at this address. They are listed nearest first.
Clinicians, nearest first (8)
Castro Valley, CA 94546
Castro Valley, CA 94546
Castro Valley, CA 94546
Castro Valley, CA 94546
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
CLIA Laboratory Certificates CMS CLIA
Laboratory certificates issued under the Clinical Laboratory Improvement Amendments (CLIA) program, which sets federal quality standards for human laboratory testing in the United States. There is no official CMS crosswalk between CLIA and NPI numbers; these certificates are associated with this NPI by matching facility names, locations and phone numbers in the CMS CLIA registry.
Certificate of Compliance 05D2315838
Gastroenterology Specialists Medical Group · Castro Valley, CAFrequently 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 Gastroenterology Specialists Medical Group, Inc A Medical Corporation's NPI number?
The NPI number for Gastroenterology Specialists Medical Group, Inc A Medical Corporation is 1629170998. It was assigned to this organization in the NPPES registry on September 5, 2006. The provider was formerly known as Gastroenterology Specialists Medical Group.
Where is Gastroenterology Specialists Medical Group, Inc A Medical Corporation located?
Gastroenterology Specialists Medical Group, Inc A Medical Corporation is located at 19845 Lake Chabot Rd Suite 104, Castro Valley, CA 94546. The listed phone number is (510) 537-4415.
What is Gastroenterology Specialists Medical Group, Inc A Medical Corporation's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.
Is Gastroenterology Specialists Medical Group, Inc A Medical Corporation enrolled in Medicare?
Yes. Gastroenterology Specialists Medical Group, Inc A Medical Corporation is registered in the Medicare PECOS enrollment system.
How many clinicians bill Medicare through Gastroenterology Specialists Medical Group, Inc A Medical Corporation?
According to the CMS Revalidation Reassignment List (October 2026 release), 8 clinicians in 3 Medicare specialties reassign their Medicare billing to Gastroenterology Specialists Medical Group, Inc A Medical Corporation. A 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 the clinician's services. The largest specialties are Gastroenterology (4), Registered Dietitian or Nutrition Professional (3) and Pathology (1). Of these, 4 practice at this address. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Does Gastroenterology Specialists Medical Group, Inc A Medical Corporation hold a CLIA laboratory certificate?
Yes. A Certificate of Compliance (number 05D2315838) is associated with this NPI, valid through November 19, 2027. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.
When was this NPI record last updated?
The NPPES record for Gastroenterology Specialists Medical Group, Inc A Medical Corporation was last updated on August 1, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Gastroenterology Specialists Medical Group, Inc A Medical Corporation · NPI 1629170998
Gastroenterology organization in Castro Valley, California. Organization record, active in the CMS NPPES registry since September 5, 2006.
## Identity
- **NPI:** 1629170998 (Entity type: Organization)
- **Enumerated:** September 5, 2006
- **Primary specialty:** Internal Medicine - Gastroenterology · taxonomy 207RG0100X
- **Organization subpart:** No
- **Authorized official:** Wei-Fang Ko Ko, PRESIDENT
## Practice location
- **Address:** 19845 LAKE CHABOT RD, SUITE 104, Castro Valley, CA 94546-4055
- **Phone:** (510) 537-4415
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Clinicians billing through this organization:** 8 clinicians in 3 Medicare specialties reassign Medicare billing to this organization (form CMS-855R); largest: Gastroenterology (4), Registered Dietitian or Nutrition Professional (3), Pathology (1); 4 practice at this address · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** August 1, 2022
- **CLIA laboratory certificates:** 1 on file
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Source: [NPI Profile](https://npiprofile.com/npi/1629170998) · Data from the CMS NPPES public registry.