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DOUGLAS LONG NGUYEN MD
NPI 1184880114
Internal Medicine - Gastroenterology in Mission Viejo, CA

Active since July 30, 2008PECOS EnrolledAccepts Medicare Assignment
27799 MEDICAL CENTER RD STE 310, MISSION VIEJO, CA 92691(949) 364-5090 Get Directions Write a Review

NPPES record last updated: May 12, 2022. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: May 12, 2022, May 4, 2021, Apr 7, 2021 and 2 more (5 updates tracked since 2019).

About Douglas Long Nguyen Md NPPES

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

DOUGLAS LONG NGUYEN MD (NPI 1184880114) is an individual gastroenterology provider in Mission Viejo, California, licensed in California (A113814) and active in the NPI registry since July 2008. He is enrolled in Medicare PECOS, maintains a secondary practice location in Loma Linda, and is a graduate of Cincinnati College Of Medicine And Surgery (2008).

NPPES Registry Identity

NPI1184880114
Entity TypeIndividualMale
Primary Taxonomy207RG0100X
Provider Legal NameDOUGLAS LONG NGUYENCredential: MD
Location Address27799 MEDICAL CENTER RD STE 310Mission Viejo, CA 92691-6400
Mailing Address27799 Medical Center Rd Ste 310Mission Viejo, CA 92691-6400 · (949) 364-5090
Phone(949) 364-5090
Sole ProprietorNo
Medical School CMSCincinnati College Of Medicine And SurgeryGraduated 2008
Enumeration DateJuly 30, 2008
Last NPPES UpdateMay 12, 20225 updates tracked since enumeration
NPPES CertifiedMay 12, 2022
✔ NPI 1184880114 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians
Taxonomy Code207RG0100X
License✔ Licensed in CA · A113814
Definition
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.
Also ListedInternal MedicineTaxonomy 207R00000X · License A113814 (CA)
27799 MEDICAL CENTER RD STE 310, Mission Viejo, CA 92691
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Secondary Practice Location 1

Location 111234 Anderson St # Mc-1516Loma Linda, CA 92354-2804 · Phone (909) 558-4905 · Fax (909) 558-4028

Other Identifiers 1

MedicaidENROLLEDMN

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Sanford Health Plan.Insurance ›

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

Douglas Long 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 ID5698811230
PECOS Enrollment IDI20121114000034
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

3

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

Providence Medical Foundation
0.2 mi
Family Medicine
26522 LA ALAMEDA, SUITE 120
Mission Viejo, CA 92691
  • Reassigned Medicare billing, California enrollment
  • 1,699 clinicians in this Medicare group
NPI 1427305960 (949) 364-9631
Faculty Physicians And Surgeons Of Llusm
9.3 mi
Internal Medicine
16305 SAND CANYON AVE, # 220
Irvine, CA 92618
  • Reassigned Medicare billing, California enrollment
  • 2,584 clinicians in this Medicare group
NPI 1417400573 (909) 558-2480
Sac Health System
29 mi
Federally Qualified Health Center (FQHC)
28078 BAXTER RD STE 540
Murrieta, CA 92563
  • Reassigned Medicare billing, California enrollment
  • 455 clinicians in this Medicare group
NPI 1164045522 (909) 382-7100

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

Areas of Expertise CMS Part B claims 10

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
345 services166 patients
Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 43239
This procedure involves using a thin, flexible tube with a light and camera, known as an endoscope, to examine the esophagus, stomach, and upper part of the small intestine. Small tissue samples are taken for further examination to help diagnose various conditions.
124 services114 patients
New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204
This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.
122 services122 patients
Removal of polyps or growths of large bowel using an endoscope with mechanical snare 45385
This procedure involves using a thin, flexible tube called an endoscope to examine the large bowel. If any abnormal growths or polyps are found, a tool called a mechanical snare is used to remove them. This is a common method to prevent potential health issues.
102 services102 patients
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
34 services26 patients
Biopsy of large bowel using a flexible endoscope 45380
A biopsy of the large bowel using a flexible endoscope is a procedure where a thin, flexible tube with a camera is inserted through the rectum to examine the bowel. If abnormal tissue is found, a small sample is taken for further examination. This helps in diagnosing conditions like inflammation, polyps, or cancer.
32 services32 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92691 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
$142.39 typical visit price
range $62.96 – $187.60
Typical copayment $35.59 (range $15.74 – $46.90)
Most-billed visit code 99204
Established Patient
$109.96 typical visit price
range $20.84 – $153.61
Typical copayment $27.49 (range $5.21 – $38.40)
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.

Referred Medical Equipment & Supplies CMS DME claims 6

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Enteral feeding supply kit; syringe fed, per day, includes but not limited to feeding/flushing syringe, administration set tubing, dressings, tape B4034
Other-Enteral and Parenteral · category OB006N
4 suppliers27 claims794 services$2.54 avg. paid by Medicare
Enteral formula, nutritionally complete with intact nutrients, includes proteins, fats, carbohydrates, vitamins and minerals, may include fiber, administered through an enteral feeding tube, 100 calories = 1 unit B4150
Other-Enteral and Parenteral · category OB006N
3 suppliers17 claims3,183 services$0.31 avg. paid by Medicare
Parenteral nutrition solution, not otherwise specified, 10 grams lipids B4185
Other-Enteral and Parenteral · category OB005N
1 supplier52 claims572 services$11.05 avg. paid by Medicare
Parenteral nutrition solution; compounded amino acid and carbohydrates with electrolytes, trace elements and vitamins, including preparation, any strength, 74 to 100 grams of protein - premix B4197
Other-Enteral and Parenteral · category OB005N
1 supplier52 claims314 services$231.49 avg. paid by Medicare
Parenteral nutrition supply kit; premix, per day B4220
Other-Enteral and Parenteral · category OB005N
1 supplier52 claims314 services$8.04 avg. paid by Medicare
Parenteral nutrition administration kit, per day B4224
Other-Enteral and Parenteral · category OB005N
1 supplier52 claims314 services$24.90 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 2

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

LIEN T NGUYEN NP
Nurse Practitioner
27799 MEDICAL CENTER RD STE 310
MISSION VIEJO, CA 92691
Orange County (949) 364-5090
DANIEL KIM MD
Internal Medicine (Gastroenterology)
27799 MEDICAL CENTER RD STE 310
MISSION VIEJO, CA 92691
Orange County (949) 364-5090

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 Douglas Nguyen's NPI number?

The NPI number for Douglas Nguyen is 1184880114. It was assigned to this individual provider in the NPPES registry on July 30, 2008.

Where is Douglas Nguyen located?

Douglas Nguyen practices at 27799 Medical Center Rd Ste 310, Mission Viejo, CA 92691. The listed phone number is (949) 364-5090.

What is Douglas Nguyen's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Douglas Nguyen enrolled in Medicare?

Yes. Douglas 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 Douglas Nguyen's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Douglas Nguyen reassigns Medicare benefits to 3 organizations: Providence Medical Foundation (Mission Viejo, CA), Faculty Physicians And Surgeons Of Llusm (Irvine, CA) and Sac Health System (Murrieta, 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 Douglas Nguyen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Douglas Nguyen accept?

Health plans from Sanford Health Plan list Douglas Nguyen as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

When was this NPI record last updated?

The NPPES record for Douglas Nguyen was last updated on May 12, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.