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DR. THIEN AN NGUYEN M.D.
NPI 1477872505
Internal Medicine - Critical Care Medicine in Katy, TX

Active since May 28, 2010PECOS EnrolledAccepts Medicare Assignment
PO BOX 475, KATY, TX 77492(281) 703-3020(281) 578-4862 Get Directions Write a Review

NPPES record last updated: August 12, 2024. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Aug 12, 2024, Jul 25, 2019 (2 updates tracked since 2019).

About Dr. Thien An Nguyen M.d. NPPES

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

DR. THIEN AN NGUYEN M.D. (NPI 1477872505) is an individual critical care medicine provider in Katy, Texas, licensed in Texas (Q9696) and active in the NPI registry since May 2010. He is enrolled in Medicare PECOS, is affiliated with St Joseph Medical Center, and maintains 2 additional practice locations.

NPPES Registry Identity

NPI1477872505
Entity TypeIndividualMale
Primary Taxonomy207RC0200X
Provider Legal NameDR. THIEN AN NGUYENCredential: M.D.
Location AddressPO BOX 475Katy, TX 77492-0475
Mailing AddressPo Box 475Katy, TX 77492-0475 · (281) 703-3020 · Fax (281) 578-4862
Phone(281) 703-3020
Fax(281) 578-4862
Sole ProprietorYes
Medical School CMSOtherGraduated 2010
Enumeration DateMay 28, 2010
Last NPPES UpdateAugust 12, 20242 updates tracked since enumeration
NPPES CertifiedAugust 12, 2024
✔ NPI 1477872505 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyInternal Medicine · Critical Care MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207RC0200X
License✔ Licensed in TX · Q9696
Definition
An internist who diagnoses, treats and supports patients with multiple organ dysfunction. This specialist may have administrative responsibilities for intensive care units and may also facilitate and coordinate patient care among the primary physician, the critical care staff and other specialists.
Also ListedInternal MedicineTaxonomy 207R00000X · License Q9696 (TX)
Also ListedInternal Medicine · Pulmonary DiseaseTaxonomy 207RP1001X · License Q9696 (TX)
PO BOX 475, Katy, TX 77492
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Secondary Practice Locations 2

Location 11401 St Joseph PkwyHouston, TX 77002-8301 · Phone (850) 607-3641
Location 2600 Elizabeth StCorpus Christi, TX 78404-2235 · Phone (361) 881-3000 · Fax (361) 881-3149

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Arizona Complete Health, Ambetter from Arkansas Health & Wellness, Ambetter from Louisiana Healthcare Connections and more.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

Dr. Thien An 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 ID8921303801
PECOS Enrollment IDI20170123001354
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

4

Medicare enrollment records show Thien Nguyen reassigns Medicare billing to 4 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Katy Critical Care Consultants PLLC
4.7 mi
Critical Care Medicine
23900 KATY FWY
Katy, TX 77494
  • Reassigned Medicare billing, Texas enrollment
  • 5 clinicians in this Medicare group
NPI 1639535511 (281) 703-3020
Sherman MD Provider Inc
23 mi
Specialist
1315 ST JOSEPH PKWY STE 806
Houston, TX 77002
  • Reassigned Medicare billing, Texas enrollment
  • 127 clinicians in this Medicare group
NPI 1669367256 (713) 756-4780
Q-Health Partners, PLLC
23 mi
Specialist
7015 ALMEDA RD STE 3
Houston, TX 77054
  • Reassigned Medicare billing, Texas enrollment
  • 31 clinicians in this Medicare group
NPI 1346647260 (713) 520-6875
Lone Star Intensivists At Gulf Coast, PLLC
42 mi
Critical Care Medicine
500 W MEDICAL CENTER BLVD
Webster, TX 77598
  • Reassigned Medicare billing, Texas enrollment
  • 76 clinicians in this Medicare group
NPI 1528558236 (281) 332-2511

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 6

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.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233
Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.
235 services76 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
204 services48 patients
Critical care, first 30-74 minutes 99291
Critical care involves immediate and constant attention by a team of specially-trained health professionals. It's for patients with life-threatening conditions, requiring first 30-74 minutes of intense monitoring and treatment.
156 services61 patients
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.
30 services15 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
17 services16 patients
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222
Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.
14 services14 patients

Hospital Affiliations CMS Care Compare 4

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

St Joseph Medical Center

Acute Care Hospitals · Houston, TX
2/5 CMS rating
OwnershipPhysician
CMS Certification Number450035
Location1401 St. Joseph ParkwayHouston, TX 77002 · Harris County
Emergency services Birthing friendly

Memorial Hermann - Texas Medical Center

Acute Care Hospitals · Houston, TX
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number450068
Location6411 FanninHouston, TX 77030 · Harris County
Emergency services Birthing friendly

Hca Houston Healthcare Southeast

Acute Care Hospitals · Pasadena, TX
4/5 CMS rating
OwnershipProprietary
CMS Certification Number450097
Location4000 Spencer HwyPasadena, TX 77504 · Harris County
Emergency services Birthing friendly

Memorial Hermann Katy Hospital

Acute Care Hospitals · Katy, TX
4/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number450847
Location23900 Katy FreewayKaty, TX 77494 · Fort Bend County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 77492 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
$134.06 typical visit price
range $58.24 – $176.98
Typical copayment $33.51 (range $14.56 – $44.24)
Most-billed visit code 99204
Established Patient
$102.71 typical visit price
range $18.60 – $143.93
Typical copayment $25.67 (range $4.65 – $35.98)
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 3

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

Home ventilator, any type, used with non-invasive interface, (e.g., mask, chest shell) E0466
DME-Other DME · category DE005N
3 suppliers24 claims24 services$911.30 avg. paid by Medicare
Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390
DME-Oxygen and Supplies · category DC002N
4 suppliers27 claims27 services$70.37 avg. paid by Medicare
Portable oxygen concentrator, rental E1392
DME-Oxygen and Supplies · category DC002N
2 suppliers15 claims15 services$31.10 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

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 Thien Nguyen's NPI number?

The NPI number for Thien Nguyen is 1477872505. It was assigned to this individual provider in the NPPES registry on May 28, 2010.

Where is Thien Nguyen located?

Thien Nguyen practices at PO Box 475, Katy, TX 77492. The listed phone number is (281) 703-3020.

What is Thien Nguyen's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Critical Care Medicine, with taxonomy code 207RC0200X.

Is Thien Nguyen enrolled in Medicare?

Yes. Thien 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 Thien Nguyen's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Thien Nguyen reassigns Medicare benefits to 4 organizations: Katy Critical Care Consultants PLLC (Katy, TX), Sherman MD Provider Inc (Houston, TX), Q-Health Partners, PLLC (Houston, TX) and Lone Star Intensivists At Gulf Coast, PLLC (Webster, TX). 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 Thien Nguyen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Thien Nguyen accept?

Health plans from Ambetter Health, Ambetter from Arizona Complete Health, Ambetter from Arkansas Health & Wellness, Ambetter from Louisiana Healthcare Connections and Ambetter from Superior HealthPlan and 4 other insurers list Thien 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.

Is Thien Nguyen affiliated with any hospitals?

According to CMS data, Thien Nguyen is affiliated with St Joseph Medical Center, Memorial Hermann - Texas Medical Center, Hca Houston Healthcare Southeast and Memorial Hermann Katy Hospital.

When was this NPI record last updated?

The NPPES record for Thien Nguyen was last updated on August 12, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.