Doctor profile · Federal record

Dr. Son Nguyen, M.D.

Internal Medicine Physician (CMS: Internal Medicine) · Fairfield, CA

  • NPI 1114119526
  • Accepts Medicare
  • MIPS 78.5 / 100 · 2023
  • 22 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
1525 Webster St, A
Fairfield, CA 945334997
(707) 423-9484
Mailing address
5184 Palace CT
Fairfield, CA 945344161

Credentials & registration

NPPES · NUCC
NPI registered
August 2007 — 19 yrs on file
Profile last updated
October 18, 2008
Year of graduation
2004 — 22 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
California #A100779

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1114119526. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
1,303
Distinct HCPCS
9
Medicare allowed
$152,910
HCPCS Description Services Patients Avg allowed
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 460 203 $133
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 344 180 $88
99239 Hospital discharge day management, more than 30 minutes 222 212 $129
99231 Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 94 49 $55
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 60 58 $194
99222 Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 59 59 $145
99221 Initial hospital care with straightforward or low level of medical decision making, per day, if using time, at least 40 minutes 31 31 $92
99238 Hospital discharge day management, 30 minutes or less 21 21 $92
99291 Critical care, first 30-74 minutes 12 12 $233

In context: peer comparison

Among 13 peers in Fairfield Internal Medicine Physician, average services per provider: 272. This provider delivers 4.8× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
124
Patients
78
Total drug cost
$13,249
Drug Type Claims Patients Total cost
Furosemide Generic 21 18 $118
Eliquis (Apixaban) Brand 16 13 $11,436
Losartan Potassium Generic 15 12 $102
Atorvastatin Calcium Generic 14 12 $103
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 12 12 $103
Hydralazine Hcl Generic 12 0 $220
Lisinopril Generic 12 0 $104
Metoprolol Succinate Generic 11 0 $171
Naloxone Hcl Generic 11 11 $892

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Son Nguyen's medical specialty?
Dr. Son Nguyen practices Internal Medicine Physician in Fairfield, CA.
Where does Dr. Son Nguyen practice?
Dr. Son Nguyen practices at 1525 Webster St, Fairfield, CA 945334997. Office phone: 7074239484.
What is Dr. Son Nguyen's NPI?
Dr. Son Nguyen's National Provider Identifier (NPI) is 1114119526, issued by NPPES.
Does Dr. Son Nguyen accept Medicare assignment?
Yes. Dr. Son Nguyen accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Son Nguyen commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Hospital discharge day management (HCPCS 99239). Source: CMS Medicare Physician & Other Practitioners file.