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

ALEXANDER DUNG NGUYEN MD
NPI 1639751746
Anesthesiology - Pain Medicine in Mission Viejo, CA

Q: What is Alexander Nguyen's NPI number?

The NPI number for Alexander Nguyen is 1639751746. It was assigned to this individual provider in the NPPES registry on April 27, 2021.

Q: What is Alexander Nguyen's specialty?

The primary specialty registered for this NPI is Anesthesiology, specializing in Pain Medicine, with taxonomy code 207LP2900X.

Q: When was this NPI record last updated?

The NPPES record for Alexander Nguyen was last updated on October 20, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 24 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.

Active since April 27, 2021PECOS Enrolled

26800 CROWN VALLEY PKWY STE 310, MISSION VIEJO, CA 92691(714) 937-2155(714) 634-4321 Get Directions Write a Review

NPPES record last updated: October 20, 2026. Verified against the NPPES registry weekly; last sync: November 08, 2026.

Record update history: Aug 31, 2026, Apr 27, 2022, Apr 19, 2022 and 1 more (4 updates tracked since 2021).

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About Alexander Dung Nguyen Md NPPES

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

ALEXANDER DUNG NGUYEN MD (NPI 1639751746) is an individual pain medicine provider in Mission Viejo, California, licensed in California (A200299) and active in the NPI registry since April 2021. He is enrolled in Medicare PECOS, maintains 3 additional practice locations, and is a graduate of University Of Colorado School Of Medicine, Aurora (2021).

NPPES Registry Identity

NPI1639751746

Entity TypeIndividualMale

Primary Taxonomy207LP2900X

Provider Legal NameALEXANDER DUNG NGUYENCredential: MD

Location Address26800 CROWN VALLEY PKWY STE 310Mission Viejo, CA 92691-8020

Mailing Address26800 Crown Valley Pkwy Ste 310Mission Viejo, CA 92691-8020 · (714) 937-2155 · Fax (714) 634-4321

Phone(714) 937-2155

Fax(714) 634-4321

Sole ProprietorNo

Medical School CMSUniversity Of Colorado School Of Medicine, AuroraGraduated 2021

Enumeration DateApril 27, 2021

Last NPPES UpdateOctober 20, 20264 updates tracked since enumeration

NPPES CertifiedOctober 20, 2026

✔ NPI 1639751746 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyAnesthesiology · Pain MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207LP2900X

License✔ Licensed in CA · A200299

Definition

An anesthesiologist who provides a high level of care, either as a primary physician or consultant, for patients experiencing problems with acute, chronic and/or cancer pain in both hospital and ambulatory settings. Patient care needs are also coordinated with other specialists.

Also ListedAnesthesiologyTaxonomy 207L00000X · License A200299 (CA)

Also ListedStudent in an Organized Health Care Education/Training ProgramTaxonomy 390200000X

26800 CROWN VALLEY PKWY STE 310, Mission Viejo, CA 92691

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Secondary Practice Locations 3

Location 1200 Lothrop StPittsburgh, PA 15213-2536 · Phone (412) 692-4947

Location 2513 Parnassus Ave # S436San Francisco, CA 94143-2205 · Phone (415) 353-1297

Location 313001 E 17th PlAurora, CO 80045-2570 · Phone (303) 724-1792

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Alexander Dung Nguyen Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID3476953548

PECOS Enrollment IDI20250912001927

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 Reassignments

Medicare enrollment records show Alexander Nguyen reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

University Anesthesia Medical Group

396 mi

Anesthesiology

505 PARNASSUS AVE
San Francisco, CA 94143

Reassigned Medicare billing, California enrollment
723 clinicians in this Medicare group

NPI 1528137296 (415) 476-1000

University Of California San Francisco

396 mi

Surgery

400 PARNASSUS AVE, MCB 300
San Francisco, CA 94143

Reassigned Medicare billing, California enrollment
5,645 clinicians in this Medicare group

NPI 1346329380 (415) 353-2161

Ucsf Medical Group Business Services

396 mi

Internal Medicine

400 PARNASSUS AVE
San Francisco, CA 94122

Reassigned Medicare billing, California enrollment
5,544 clinicians in this Medicare group

NPI 1477624104 (415) 353-2808

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 Alexander Nguyen's NPI number?

The NPI number for Alexander Nguyen is 1639751746. It was assigned to this individual provider in the NPPES registry on April 27, 2021.

Where is Alexander Nguyen located?

Alexander Nguyen practices at 26800 Crown Valley Pkwy Ste 310, Mission Viejo, CA 92691. The listed phone number is (714) 937-2155.

What is Alexander Nguyen's specialty?

The primary specialty registered for this NPI is Anesthesiology, specializing in Pain Medicine, with taxonomy code 207LP2900X.

Is Alexander Nguyen enrolled in Medicare?

Yes. Alexander Nguyen is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for Alexander Nguyen's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Alexander Nguyen reassigns Medicare benefits to 3 organizations: University Anesthesia Medical Group (San Francisco, CA), University Of California San Francisco (San Francisco, CA) and Ucsf Medical Group Business Services (San Francisco, CA). Each 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 Alexander 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 Alexander Nguyen was last updated on October 20, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 24 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.