Quick answers
- Does Douglas L. Nguyen accept Medicare assignment?
- Yes. Medicare's clinician data says Douglas L. 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 Douglas L. Nguyen see?
- In 2024, CMS data shows 318 Original Medicare patients and 946 services for Douglas L. Nguyen. This counts Original Medicare only and measures volume, not quality.
- What is Douglas L. Nguyen's NPI number?
- 1184880114. 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 Douglas L. 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 | 318 |
|---|---|
| Services billed to Medicare | 946 |
| Different services or procedures | 41 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)345 services
- Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope (43239)124 services
- New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)122 services
- Removal of polyps or growths of large bowel using an endoscope with mechanical snare (45385)102 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)34 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 cholesterol75%
- High blood pressure72%
- Arthritis51%
- Ischemic heart disease30%
- Anxiety25%
- Diabetes21%
Hospitals where Douglas L. Nguyen works
Medicare's Facility Affiliation Data lists Douglas L. Nguyen at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Hoag Memorial Hospital PresbyterianNewport Beach, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050224
- Providence Mission HospitalMission Viejo, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050567
Practice locations
Addresses where Douglas L. Nguyen is enrolled with Medicare (CMS data updated October 2, 2026).
- 1950 Sunny Crest Dr, Suite 2900Fullerton, CA 92835 (714) 992‑5350
- 27700 Medical Ctr RdMission Viejo, CA 92691 (949) 364‑1400
- 27799 Medical Ctr RdMission Viejo, CA 92691
Group practices
Medicare enrollment lists Douglas L. Nguyen as a member of this group (CMS data updated October 2, 2026).
- Providence Medical Foundation1,466 clinicians in the group
Specialties
- Gastroenterologyprimary
- Internal Medicinealso
Other gastroenterologists in Fullerton
Clinicians with the same Medicare primary specialty in Fullerton, CA — not a recommendation.
Other clinicians in Providence Medical Foundation
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Cincinnati College Of Medicine And Surgery |
| Graduation year | 2008 (18 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) | 1184880114 |
| 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- 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