What is Hai Nguyen's specialty?

Hai Nguyen (NPI 1558516963) is a Medicare-billing provider whose primary specialty is Internal Medicine in Santa Ana, CA.

Where does Hai Nguyen practice?

Hai Nguyen practices in Santa Ana, CA, based on the location reported in the CMS Medicare provider datasets for NPI 1558516963.

How much does Medicare pay Hai Nguyen?

Hai Nguyen (NPI 1558516963) received approximately $155K in total Medicare Part B payments, serving 204 beneficiaries, per the CMS Medicare Physician & Other Practitioners dataset.

PROVIDER PROFILE · NPI 1558516963

Hai NguyenM.D.

Internal MedicineSanta Ana, CAI

MEDICARE UTILIZATION · PART B · 2024

Total beneficiaries

477

Unique beneficiaries

—

Total services

1,830

Distinct HCPCS

Medicare payment

$154K

Peer benchmark

Total Medicare services vs. 10,499 Internal Medicine providers in CA — top quintile (cohort median 531).

PRESCRIBING · PART D · 2024

Total Rx claims

903

Beneficiaries

—

Total drug cost

$27K

Distinct drugs

Brand share

10.9%

Top prescribed drugs

Pantoprazole Sodium68 claims

Cephalexin65 claims

Atorvastatin Calcium56 claims

Cefdinir53 claims

Metoprolol Tartrate50 claims

QUALITY · MIPS · 2024

No data available for this provider in 2024.

INDUSTRY PAYMENTS · OPEN PAYMENTS · 2025

No data available for this provider in 2025.

REFERRAL NETWORK

Where Hai Nguyen's patients come from & go

Directional shared-patient flow from Medicare claims — who sends patients to this provider (inbound) and where this provider's patients go next (outbound). 63 inbound referrers · 0 outbound destinations.

Receives referrals from

Inbound — who sends patients here

Physician	Patients	Visits
RIVERSIDE HEALTHCARE SYSTEM, L.P.	186	610
HAI DONG NGUYEN, M.D., CORP.	160	448
Jason Beck Diagnostic Radiology · Temecula, CA	109	402
Douglas Green Diagnostic Radiology · Temecula, CA	95	396
David Lawson Diagnostic Radiology · Wildomar, CA	93	330
David Scafidi Diagnostic Radiology · Wildomar, CA	87	305
James Stapakis Diagnostic Radiology · Wildomar, CA	77	233
UNIVERSAL HEALTH SERVICES OF RANCHO SPRINGS INC	73	136
Ardavan Afshar Diagnostic Radiology · Riverside, CA	66	191
Johnny Liquete Infectious Disease · Moreno Valley, CA	50	177
Robin Abdelmalik Cardiology · Temecula, CA	47	171
Indraneel Chakrabarty Gastroenterology · Temecula, CA	46	201

Refers patients to

Outbound — where patients go next

No outbound pairs above the suppression threshold.

Source: CMS Physician Shared Patient Patterns (30-day window, Medicare FFS). Direction = a beneficiary seen by the first provider, then the second, within 30 days; a proxy for referral, not a documented referral. Pairs with fewer than 11 shared beneficiaries are suppressed.

CROSS-REFERENCE

Related data on other Healthparse brands

ProviderScore

OIG/SAM exclusion screening, sanctions history

Healthparse Signals

Monitor this provider for changes — dated NPI change events