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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DR. TIMOTHY ANDREW ZAKI MD
NPI 1790312486
Internal Medicine - Gastroenterology in Irvine, CA

Active since March 24, 2020PECOS Enrolled
113 WATERWORKS WAY STE 155, IRVINE, CA 92618(949) 612-9090 Get Directions Write a Review

NPPES record last updated: August 31, 2026. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Aug 31, 2026, Jul 7, 2023, Mar 24, 2020 (3 updates tracked since 2020).

About Dr. Timothy Andrew Zaki Md NPPES

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

DR. TIMOTHY ANDREW ZAKI MD (NPI 1790312486) is an individual gastroenterology provider in Irvine, California, licensed in California (185201) and active in the NPI registry since March 2020. He is enrolled in Medicare PECOS and is a graduate of New York University School Of Medicine (2020).

NPPES Registry Identity

NPI1790312486
Entity TypeIndividualMale
Primary Taxonomy207RG0100X
Provider Legal NameDR. TIMOTHY ANDREW ZAKICredential: MD
Location Address113 WATERWORKS WAY STE 155Irvine, CA 92618-3163
Mailing Address113 Waterworks Way Ste 155Irvine, CA 92618-3163 · (949) 612-9090
Phone(949) 612-9090
Sole ProprietorNo
Medical School CMSNew York University School Of MedicineGraduated 2020
Enumeration DateMarch 24, 2020
Last NPPES UpdateAugust 31, 20263 updates tracked since enumeration
NPPES CertifiedAugust 31, 2026
✔ NPI 1790312486 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians
Taxonomy Code207RG0100X
License✔ Licensed in CA · 185201
Definition
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.
113 WATERWORKS WAY STE 155, Irvine, CA 92618
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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. Timothy Andrew Zaki Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

PECOS PAC ID7315403169
PECOS Enrollment IDI20260731000918
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 Timothy Zaki reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Digestive Disease Consultants Of Orange County Inc
Same address
Gastroenterology
113 WATERWORKS WAY, SUITE 155
Irvine, CA 92618
  • Reassigned Medicare billing, California enrollment
  • 11 clinicians in this Medicare group
NPI 1780843458 (949) 612-9090

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 92618 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
$142.39 typical visit price
range $62.96 – $187.60
Typical copayment $35.59 (range $15.74 – $46.90)
Most-billed visit code 99204
Established Patient
$109.96 typical visit price
range $20.84 – $153.61
Typical copayment $27.49 (range $5.21 – $38.40)
Most-billed visit code 99214
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 11

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

YASAMAN SHAKERANEH
Physician Assistant
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 612-9090
DR. KEYVAN FARHAD ND
Naturopath
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 612-9090
KHATERE NADERI-ASHOUR AGNP
Nurse Practitioner
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 612-9090
ELAINE GEEAEH WON
Nurse Practitioner
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 612-9090
TAAHIRA SIDDIQUI PA-C
Physician Assistant
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 612-9090
MRS. LESLIE WHITNEY PA-C
Physician Assistant
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 612-9090
DR. SHAHROOZ BEMANIAN
Internal Medicine (Gastroenterology)
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 612-9090
HEBA ASHRAF MD
Internal Medicine (Gastroenterology)
113 WATERWORKS WAY STE 155
IRVINE, CA 92618
Orange County (949) 258-7229

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 Timothy Zaki's NPI number?

The NPI number for Timothy Zaki is 1790312486. It was assigned to this individual provider in the NPPES registry on March 24, 2020.

Where is Timothy Zaki located?

Timothy Zaki practices at 113 Waterworks Way Ste 155, Irvine, CA 92618. The listed phone number is (949) 612-9090.

What is Timothy Zaki's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Timothy Zaki enrolled in Medicare?

Yes. Timothy Zaki is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Timothy Zaki's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Timothy Zaki reassigns Medicare benefits to Digestive Disease Consultants Of Orange County 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 Timothy Zaki'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 Timothy Zaki was last updated on August 31, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 50 days 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.