1. Home
  2. Directory
  3. California
  4. Fountain Valley
  5. Internal Medicine
  6. NPI Profile

CHRIS TSIMEREKIS, M.D., INC.
NPI 1801907704
Internal Medicine - Endocrinology, Diabetes & Metabolism in Fountain Valley, CA

Active since August 31, 2006
11100 WARNER AVE, SUITE 354, FOUNTAIN VALLEY, CA 92708(714) 549-9927(714) 556-9075 Get Directions Write a Review

NPPES record last updated: December 6, 2012. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Chris Tsimerekis, M.d., Inc. NPPES

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

CHRIS TSIMEREKIS, M.D., INC. (NPI 1801907704) is a healthcare organization registered as an endocrinology, diabetes & metabolism in Fountain Valley, California and active in the NPI registry since August 2006. The organization lists Chris Tsimerekis, President, as its authorized official.

NPPES Registry Identity

NPI1801907704
Entity TypeOrganization
Primary Taxonomy207RE0101X
Legal Business NameCHRIS TSIMEREKIS, M.D., INC.
Location Address11100 WARNER AVE, SUITE 354Fountain Valley, CA 92708-7506
Mailing Address11100 Warner Ave, Suite 354Fountain Valley, CA 92708-7506 · (714) 549-9927 · Fax (714) 556-9075
Phone(714) 549-9927
Fax(714) 556-9075
Organization SubpartNo
Authorized OfficialChris TsimerekisPresident · (714) 549-9927
Enumeration DateAugust 31, 2006
Last NPPES UpdateDecember 6, 2012
✔ NPI 1801907704 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · Endocrinology, Diabetes & MetabolismAllopathic & Osteopathic Physicians
Taxonomy Code207RE0101X
License✔ Licensed in CA · G811410
Definition
An internist who concentrates on disorders of the internal (endocrine) glands such as the thyroid and adrenal glands. This specialist also deals with disorders such as diabetes, metabolic and nutritional disorders, obesity, pituitary diseases and menstrual and sexual problems.
11100 WARNER AVE, Fountain Valley, CA 92708
Open in Google Maps ↗

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment, revalidation and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Chris Tsimerekis, M.d., Inc. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Medicare Revalidation Due Date

Revalidation due by March 31, 2027

Medicare-enrolled providers and suppliers confirm their enrollment information with CMS on a set cycle, every 5 years for most and every 3 years for medical equipment suppliers. CMS sets the due date for each enrollment.

StateEnrollment IDDue date
StateCaliforniaEnrollment IDO20121105000538Non-DME Part B · Clinic/Group PracticeDue dateMarch 31, 2027
Source: CMS Revalidation Due Date List, October 2026 release.

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 1 clinician reassigns Medicare billing to Chris Tsimerekis, M.D., Inc., which bills Medicare for the services this clinician delivers.

Clinician (1)

Chris Tsimerekis, M.D.
Endocrinology
NPI 1942311832
11100 WARNER AVE SUITE 354
Fountain Valley, CA 92708
(714) 549-9927
✔ PECOS✔ Accepts Medicare0.1 mi

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 Chris Tsimerekis, M.D., Inc.'s NPI number?

The NPI number for Chris Tsimerekis, M.D., Inc. is 1801907704. It was assigned to this organization in the NPPES registry on August 31, 2006.

Where is Chris Tsimerekis, M.D., Inc. located?

Chris Tsimerekis, M.D., Inc. is located at 11100 Warner Ave Suite 354, Fountain Valley, CA 92708. The listed phone number is (714) 549-9927.

What is Chris Tsimerekis, M.D., Inc.'s specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Endocrinology, Diabetes & Metabolism, with taxonomy code 207RE0101X.

Is Chris Tsimerekis, M.D., Inc. enrolled in Medicare?

Yes. Chris Tsimerekis, M.D., Inc. is registered in the Medicare PECOS enrollment system.

When is Chris Tsimerekis, M.D., Inc.'s Medicare revalidation due?

According to the CMS Revalidation Due Date List (October 2026 release), the Medicare Non-DME Part B enrollment for this organization (California, Clinic/Group Practice) is due for revalidation by March 31, 2027. Medicare providers and suppliers revalidate their enrollment every 5 years, and medical equipment suppliers every 3 years. Confirm current requirements with your Medicare Administrative Contractor.

How many clinicians bill Medicare through Chris Tsimerekis, M.D., Inc.?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Endocrinology) reassigns their Medicare billing to Chris Tsimerekis, M.D., Inc.. 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. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Chris Tsimerekis, M.D., Inc. was last updated on December 6, 2012. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 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.