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DEREK C. ABBASSI MD
NPI 1841364155
Obstetrics & Gynecology in Walnut Creek, CA

Active since November 20, 2006PECOS Enrolled
1425 S MAIN ST, WALNUT CREEK, CA 94596(925) 295-4000 Get Directions Write a Review

NPPES record last updated: July 8, 2007. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Derek C. Abbassi Md NPPES

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

DEREK C. ABBASSI MD (NPI 1841364155) is an individual obstetrics & gynecology provider in Walnut Creek, California, licensed in California (A63678) and active in the NPI registry since November 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1841364155
Entity TypeIndividualMale
Primary Taxonomy207V00000X
Provider Legal NameDEREK C. ABBASSICredential: MD
Location Address1425 S MAIN STWalnut Creek, CA 94596-5318
Mailing Address1800 Harrison St Fl 7Oakland, CA 94612-3429 · (510) 625-6262
Phone(925) 295-4000
Sole ProprietorNo
Enumeration DateNovember 20, 2006
Last NPPES UpdateJuly 8, 2007
✔ NPI 1841364155 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyObstetrics & GynecologyAllopathic & Osteopathic Physicians
Taxonomy Code207V00000X
License✔ Licensed in CA · A63678
Definition
An obstetrician/gynecologist possesses special knowledge, skills and professional capability in the medical and surgical care of the female reproductive system and associated disorders. This physician serves as a consultant to other physicians and as a primary physician for women.
1425 S MAIN ST, Walnut Creek, CA 94596
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Other Identifiers 3

Medicare UPINH85162
Medicaid00A636780CA
Medicare ID-Type Unspecified00A636780

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Derek C. Abbassi 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 Reassignment

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

Permanente Medical Group Inc
17 mi
Internal Medicine
901 NEVIN
Richmond, CA 94801
  • Reassigned Medicare billing, California enrollment
  • 20,078 clinicians in this Medicare group
NPI 1235226531 (510) 307-1555

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

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94596 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$153.83 typical visit price
range $69.00 – $202.35
Typical copayment $38.45 (range $17.25 – $50.58)
Most-billed visit code 99204
Established Patient
$84.91 typical visit price
range $23.44 – $166.46
Typical copayment $21.22 (range $5.86 – $41.61)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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.

BROOK ANDREW WOOLLEY M.D.
Emergency Medicine
1425 S MAIN ST, EMERGENCY MEDICINE DEPARTMENT
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-5100
DR. THOMAS CRESANTE D.O.
Hospitalist
1425 S MAIN ST, KAISER PERMANENTE WALNUT CREEK ATTN: HBS DEPT
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-4643
SARA WON MD
Obstetrics & Gynecology
1425 S MAIN ST
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-4040
KAISER PERMANENTE
General Acute Care Hospital
1425 S MAIN ST
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-4000
MICHELLE CABLE VU CRNA
Nurse Anesthetist, Certified Registered
1425 S MAIN ST
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-4000
DR. JESUS GIL JIMENEZ MD
Surgery (Vascular Surgery)
1425 S MAIN ST
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-4110
MR. EDWARD HAL PIECZENIK L.C.S.W.
Social Worker (Clinical)
1425 S MAIN ST
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-5237
CARLOS A. CROMEYER MD
Psychiatry & Neurology (Neurology)
1425 S MAIN ST
WALNUT CREEK, CA 94596
Contra Costa County (925) 295-4000

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 Derek Abbassi's NPI number?

The NPI number for Derek Abbassi is 1841364155. It was assigned to this individual provider in the NPPES registry on November 20, 2006.

Where is Derek Abbassi located?

Derek Abbassi practices at 1425 S Main St, Walnut Creek, CA 94596. The listed phone number is (925) 295-4000.

What is Derek Abbassi's specialty?

The primary specialty registered for this NPI is Obstetrics & Gynecology with taxonomy code 207V00000X.

Is Derek Abbassi enrolled in Medicare?

Yes. Derek Abbassi is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Derek Abbassi's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Derek Abbassi reassigns Medicare benefits to Permanente Medical Group Inc (Richmond, 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 Derek Abbassi'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 Derek Abbassi was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 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.