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DR. ALEXANDER SI NGUYEN M.D.
NPI 1487186581
Anesthesiology - Pain Medicine in Seattle, WA

Active since March 29, 2017PECOS EnrolledAccepts Medicare Assignment
925 SENECA STREET, MAIL STOP H8-GME, SEATTLE, WA 98101(206) 583-6079 Get Directions Write a Review

NPPES record last updated: August 21, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Dr. Alexander Si Nguyen M.d. NPPES

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

DR. ALEXANDER SI NGUYEN M.D. (NPI 1487186581) is an individual pain medicine provider in Seattle, Washington, licensed in New York (317013-01) and active in the NPI registry since March 2017. He is enrolled in Medicare PECOS, is affiliated with Spectrum Health, and maintains a secondary practice location in Oak Lawn.

NPPES Registry Identity

NPI1487186581
Entity TypeIndividualMale
Primary Taxonomy207LP2900X
Provider Legal NameDR. ALEXANDER SI NGUYENCredential: M.D.
Location Address925 SENECA STREET, MAIL STOP H8-GMESeattle, WA 98101
Mailing Address925 Seneca St, Mail Stop H8-gmeSeattle, WA 98101-2742 · (206) 583-6079
Phone(206) 583-6079
Sole ProprietorNo
Medical School CMSUniversity Of Virginia School Of MedicineGraduated 2017
Enumeration DateMarch 29, 2017
Last NPPES UpdateAugust 21, 2025
NPPES CertifiedAugust 21, 2025
✔ NPI 1487186581 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyAnesthesiology · Pain MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207LP2900X
License✔ Licensed in NY · 317013-01
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 317013-01 (NY), 036176521 (IL)
925 SENECA STREET, Seattle, WA 98101
Open in Google Maps ↗

Secondary Practice Location 1

Location 14440 W 95th St Dept OfOak Lawn, IL 60453-2600 · Phone (708) 684-8000

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

Dr. Alexander Si Nguyen M.d. 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 ID2860760113
PECOS Enrollment IDI20220830001471, I20251129000612
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

6

Medicare enrollment records show Alexander Nguyen reassigns Medicare billing to 6 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Advocate Health And Hospitals Corp.
1,696 mi
Medicare Defined Swing Bed Unit
101 S MAJOR ST
Eureka, IL 61530
  • Reassigned Medicare billing, Illinois enrollment
  • 4,870 clinicians in this Medicare group
NPI 1295066983 (309) 467-2371
Spectrum Health Primary Care Partners
1,764 mi
Physical Therapist
2009 HOLTON ROAD
Muskegon, MI 49445
  • Reassigned Medicare billing, Michigan enrollment
  • 2,446 clinicians in this Medicare group
NPI 1386194538 (616) 486-6790
Northstar Anesthesia Of Virginia, LLC
2,331 mi
Anesthesiology
2501 PARKERS LN
Alexandria, VA 22306
  • Reassigned Medicare billing, District of Columbia enrollment
  • 634 clinicians in this Medicare group
NPI 1194488791 (214) 687-0497
New York University
2,395 mi
Cardiovascular Disease
1985 CROMPOND RD
Cortlandt Manor, NY 10567
  • Reassigned Medicare billing, New York enrollment
  • 1,074 clinicians in this Medicare group
NPI 1881987246 (914) 736-0703
North Shore - Lij Anesthesiology, PC
2,405 mi
Anesthesiology
480 BEDFORD RD BLDG B
Chappaqua, NY 10514
  • Reassigned Medicare billing, New York enrollment
  • 1,406 clinicians in this Medicare group
NPI 1417401266 (914) 666-8866
Trustees Of Columbia University In The City Of New York
2,407 mi
Surgery
622 W 168TH ST
New York, NY 10032
  • Reassigned Medicare billing, New York enrollment
  • 3,922 clinicians in this Medicare group
NPI 1508266347 (646) 317-7111

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

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Spectrum Health

Acute Care Hospitals · Grand Rapids, MI
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number230038
Location100 Michigan St NEGrand Rapids, MI 49503 · Kent County
Emergency services Birthing friendly

Other Providers at the Same Location NPPES 4

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

SEATTLE EXTRACORPOREAL
General Acute Care Hospital (Critical Access)
925 SENECA STREET, SEATTLE EXTRACORPOREAL
SEATTLE, WA 98101
King County (206) 223-6600
KATHERINE MCMANUS PHARMD
Pharmacist
925 SENECA STREET, H3-PI
SEATTLE, WA 98101
King County (206) 583-6011
MEREDITH P JOHNSON
Student in an Organized Health Care Education/Training Program
925 SENECA STREET, MAIL SOP: H8 GME
SEATTLE, WA 98101
King County (206) 583-6079
BAOANH VU MD
Student in an Organized Health Care Education/Training Program
925 SENECA STREET, H8-GME
SEATTLE, WA 98101
King County (206) 223-6600

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 1487186581. It was assigned to this individual provider in the NPPES registry on March 29, 2017.

Where is Alexander Nguyen located?

Alexander Nguyen practices at 925 Seneca Street Mail Stop H8-Gme, Seattle, WA 98101. The listed phone number is (206) 583-6079.

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 6 organizations: Advocate Health And Hospitals Corp. (Eureka, IL), Spectrum Health Primary Care Partners (Muskegon, MI), Northstar Anesthesia Of Virginia, LLC (Alexandria, VA), New York University (Cortlandt Manor, NY), North Shore - Lij Anesthesiology, PC (Chappaqua, NY) and 1 more organization, listed in the Medicare section above. 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.

Is Alexander Nguyen affiliated with any hospitals?

According to CMS data, Alexander Nguyen is affiliated with Spectrum Health.

When was this NPI record last updated?

The NPPES record for Alexander Nguyen was last updated on August 21, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 months 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.