Doctor profile · Federal record

Dr. Lonnie Seo

Emergency Medicine Physician (CMS: Emergency Medicine) · Student in an Organized Health Care Education/Training Program · New Haven, CT

  • NPI 1740785211
  • Accepts Medicare
  • 8 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

Operates at 2 locations .

NPPES Updated May 11, 2026
Primary practice
464 Congress Ave Ste 260
New Haven, CT 065191362
(203) 737-2644
Additional location
1 Hospital Plz
Stamford, CT 069023602
(201) 658-2042

Credentials & registration

NPPES · NUCC
NPI registered
March 2018 — 8 yrs on file
Profile last updated
April 14, 2022
Year of graduation
2018 — 8 yrs since
Specialty taxonomy
207P00000X — NUCC code
State license (1)
Connecticut #67025

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1740785211. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
711
Distinct HCPCS
8
Medicare allowed
$118,110
HCPCS Description Services Patients Avg allowed
99285 Emergency department visit with high level of medical decision making 254 243 $179
99291 Critical care, first 30-74 minutes 205 200 $217
99284 Emergency department visit with moderate level of medical decision making 154 145 $124
99283 Emergency department visit with low level of medical decision making 22 22 $74
99204 New patient office or other outpatient visit, 45-59 minutes 21 21 $138
99203 New patient office or other outpatient visit, 30-44 minutes 20 20 $86
99213 Established patient office or other outpatient visit, 20-29 minutes 18 18 $68
99214 Established patient office or other outpatient visit, 30-39 minutes 17 17 $101

In context: peer comparison

Among 76 peers in New Haven Emergency Medicine Physician, average services per provider: 72. This provider delivers 9.9× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
130
Patients
130
Total drug cost
$952
Drug Type Claims Patients Total cost
Cephalexin Generic 46 46 $479
Prednisone Generic 16 16 $36
Sulfamethoxazole-Trimethoprim (Sulfamethoxazole/Trimethoprim) Brand 15 15 $76
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 14 14 $189
Azithromycin Generic 14 14 $59
Ondansetron Odt (Ondansetron) Brand 14 14 $85
Oxycodone Hcl Generic 11 11 $29

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Lonnie Seo's medical specialty?
Dr. Lonnie Seo practices Emergency Medicine Physician in New Haven, CT.
Where does Dr. Lonnie Seo practice?
Dr. Lonnie Seo practices at 464 Congress Ave Ste 260, New Haven, CT 065191362. Office phone: 2037372644.
What is Dr. Lonnie Seo's NPI?
Dr. Lonnie Seo's National Provider Identifier (NPI) is 1740785211, issued by NPPES.
Does Dr. Lonnie Seo accept Medicare assignment?
Yes. Dr. Lonnie Seo accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Lonnie Seo commonly perform?
Top Medicare-reported procedures in 2023: Emergency department visit with high level of medical decision making (HCPCS 99285); Critical care (HCPCS 99291); Emergency department visit with moderate level of medical decision making (HCPCS 99284). Source: CMS Medicare Physician & Other Practitioners file.