Doctor profile · Federal record

Dr. Seng Leong, MD

Internal Medicine Physician (CMS: Internal Medicine) · Barrington, IL

  • NPI 1487750790
  • Accepts Medicare
  • 57 yrs in practice
  • Male
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
27750 W Highway 22
Barrington, IL 600102379
(847) 381-5800
fax (847) 381-5873
Mailing address
29373 Network Pl
Chicago, IL 606731293

Credentials & registration

NPPES · NUCC
NPI registered
September 2006 — 20 yrs on file
Profile last updated
March 31, 2025
Year of graduation
1969 — 57 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
Illinois #036-055809
Medicaid
IL #03655809

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1487750790. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
3,159
Distinct HCPCS
10
Medicare allowed
$276,144
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 1,057 527 $132
36415 Insertion of needle into vein for collection of blood sample 906 510 $8
G0439 Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit 229 229 $133
G0008 Administration of influenza virus vaccine 160 155 $32
90662 Influenza vaccine split virus, preservative free 155 150 $72
99215 Established patient office or other outpatient visit, 40-54 minutes 143 125 $184
G0438 Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit 112 112 $169
99213 Established patient office or other outpatient visit, 20-29 minutes 93 79 $93
G0009 Administration of pneumococcal vaccine 78 78 $32
93000 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 70 68 $15

In context: peer comparison

Among 7 peers in Barrington Internal Medicine Physician, average services per provider: 149. This provider delivers 21× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
6,593
Patients
1,884
Total drug cost
$84,133
Drug Type Claims Patients Total cost
Atorvastatin Calcium Generic 1,076 299 $13,842
Amlodipine Besylate Generic 910 259 $8,602
Levothyroxine Sodium Generic 515 145 $7,822
Losartan Potassium Generic 511 150 $7,486
Metoprolol Succinate Generic 449 134 $9,180
Lisinopril Generic 413 113 $4,205
Omeprazole Generic 383 125 $5,697
Hydrochlorothiazide Generic 369 117 $3,010
Metoprolol Tartrate Generic 343 89 $3,904
Gabapentin Generic 298 77 $4,955

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Seng Leong's medical specialty?
Dr. Seng Leong practices Internal Medicine Physician in Barrington, IL.
Where does Dr. Seng Leong practice?
Dr. Seng Leong practices at 27750 W Highway 22, Barrington, IL 600102379. Office phone: 8473815800.
What is Dr. Seng Leong's NPI?
Dr. Seng Leong's National Provider Identifier (NPI) is 1487750790, issued by NPPES.
Does Dr. Seng Leong accept Medicare assignment?
Yes. Dr. Seng Leong accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Seng Leong commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Insertion of needle into vein for collection of blood sample (HCPCS 36415); Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (HCPCS G0439). Source: CMS Medicare Physician & Other Practitioners file.