Quick answers
- Does William T. Nguyen accept Medicare assignment?
- Yes. Medicare's clinician data says William T. Nguyen accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does William T. Nguyen see?
- In 2024, CMS data shows 251 Original Medicare patients and 11,522 services for William T. Nguyen. This counts Original Medicare only and measures volume, not quality.
- What is William T. Nguyen's NPI number?
- 1861445017. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for William T. Nguyen, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 251 |
|---|---|
| Services billed to Medicare | 11,522 |
| Different services or procedures | 35 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Injection, omalizumab, 5 mg (J2357)5,520 services
- Test for allergy using allergenic extract (95004)1,166 services
- Injection of drug or substance under skin or into muscle (96372)240 services
- Professional service for multiple injections of allergen (95117)183 services
- Professional service for single injection of allergen (95115)138 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol68%
- High blood pressure55%
- Asthma52%
- Arthritis47%
- Anxiety23%
- Ischemic heart disease19%
Practice locations
Addresses where William T. Nguyen is enrolled with Medicare (CMS data updated October 2, 2026).
- 9725 3rd Ave NE, Suite 500Seattle, WA 98115 (206) 527‑1200
Group practices
Medicare enrollment lists William T. Nguyen as a member of this group (CMS data updated October 2, 2026).
- Northwest Asthma and Allergy Center11 clinicians in the group
Specialties
- Allergy/Immunologyprimary
Other allergist and immunologists in Seattle
Clinicians with the same Medicare primary specialty in Seattle, WA — not a recommendation.
Other clinicians in Northwest Asthma and Allergy Center
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Texas Medical School At Houston |
| Graduation year | 1997 (29 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1861445017 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians