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KHOA DANG NGUYEN M.D.
NPI 1386962421
Internal Medicine in Castro Valley, CA

Active since May 13, 2010PECOS Enrolled
20103 LAKE CHABOT RD, CASTRO VALLEY, CA 94546(510) 727-3256(510) 727-3107 Get Directions Write a Review

NPPES record last updated: October 19, 2020. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Oct 19, 2020, Mar 17, 2018, Dec 1, 2017 and 1 more (4 updates tracked since 2017).

About Khoa Dang Nguyen M.d. NPPES

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

KHOA DANG NGUYEN M.D. (NPI 1386962421) is an individual internal medicine provider in Castro Valley, California, licensed in California (A111239) and active in the NPI registry since May 2010. He is enrolled in Medicare PECOS and maintains a secondary practice location in Hesperia.

NPPES Registry Identity

NPI1386962421
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameKHOA DANG NGUYENCredential: M.D.
Location Address20103 LAKE CHABOT RDCastro Valley, CA 94546-5305
Mailing Address3687 Mt Diablo Blvd Ste 200Lafayette, CA 94549-3746 · (916) 854-6975
Phone(510) 727-3256
Fax(510) 727-3107
Sole ProprietorNo
Enumeration DateMay 13, 2010
Last NPPES UpdateOctober 19, 20204 updates tracked since enumeration
NPPES CertifiedOctober 19, 2020
✔ NPI 1386962421 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in CA · A111239
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
20103 LAKE CHABOT RD, Castro Valley, CA 94546
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Secondary Practice Location 1

Location 117095 Main StHesperia, CA 92345-6004 · Phone (760) 241-6666 · Fax (760) 947-5619

Other Identifiers 1

OtherA111239CA · State License

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Khoa Dang Nguyen M.d. 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 Khoa Nguyen reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Ashit Jain MD Inc
11 mi
Internal Medicine
2000 MOWRY AVE, WASHINGTON HOSPITAL
Fremont, CA 94538
  • Reassigned Medicare billing, California enrollment
  • 7 clinicians in this Medicare group
NPI 1720098387 (510) 795-2013

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 94546 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
$119.48 typical visit price
range $23.44 – $166.46
Typical copayment $29.87 (range $5.86 – $41.61)
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 20

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

DR. OLUWASEYI SEGUN BALASIRE M.D.
Hospitalist
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (510) 727-3256
LATRICIA A AMADEO RN
Registered Nurse
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (205) 915-5496
SARAH NOONBERG MD, PHD
Internal Medicine
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (510) 889-5082
DR. MOYRA N RASHEED M.B.B.S
Hospitalist
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (510) 727-3256
DOMINIC K TRAN PHARMD
Pharmacist (Ambulatory Care)
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (510) 537-1234
THOMAS EALES DO
Emergency Medicine
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (510) 727-3320
OMAR FAISAL SALEEM MD
Internal Medicine
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (510) 727-3256
HELENA CHUNG RD, MPH
Dietitian, Registered
20103 LAKE CHABOT RD
CASTRO VALLEY, CA 94546
Alameda County (510) 727-3204

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 Khoa Nguyen's NPI number?

The NPI number for Khoa Nguyen is 1386962421. It was assigned to this individual provider in the NPPES registry on May 13, 2010.

Where is Khoa Nguyen located?

Khoa Nguyen practices at 20103 Lake Chabot Rd, Castro Valley, CA 94546. The listed phone number is (510) 727-3256.

What is Khoa Nguyen's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Khoa Nguyen enrolled in Medicare?

Yes. Khoa Nguyen is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Khoa Nguyen's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Khoa Nguyen reassigns Medicare benefits to Ashit Jain MD Inc (Fremont, 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 Khoa Nguyen'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 Khoa Nguyen was last updated on October 19, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 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.