Doctor profile · Federal record

Dr. Themistocles Dassopoulos, MD

Gastroenterology Physician (CMS: Gastroenterology) · Gastroenterology Physician · Dallas, TX

  • NPI 1326083148
  • Accepts Medicare
  • 35 yrs in practice
  • Licensed in 2 states
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
3409 Worth Street, Suite 640
Dallas, TX 75246
(469) 800-7180
fax (469) 800-7190

Credentials & registration

NPPES · NUCC
NPI registered
June 2006 — 20 yrs on file
Profile last updated
September 2, 2016
Year of graduation
1991 — 35 yrs since
Specialty taxonomy
207RG0100X — NUCC code
State licenses (2)
Texas #Q0899 · Missouri #2008001013
Medicaid
TX #3445801-01

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1326083148. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
159
Distinct HCPCS
6
Medicare allowed
$13,805
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 43 34 $125
36415 Insertion of needle into vein for collection of blood sample 30 21 $8
99221 Initial hospital care with straightforward or low level of medical decision making, per day, if using time, at least 40 minutes 27 26 $82
45380 Biopsy of large bowel using a flexible endoscope 24 22 $144
99231 Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 18 15 $45
43239 Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 17 17 $101

In context: peer comparison

Among 53 peers in this city , average services per provider: 41. This provider delivers 3.9× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$3,439
Transactions
106
Manufacturers
13
Payer (manufacturer) Industry Txns Amount
Merck Sharp & Dohme LLC 14 $1,506.37
ABBVIE INC. 31 $650.44
Takeda Pharmaceuticals U.S.A., Inc. 16 $392.20
Celgene Corporation 9 $151.60
Janssen Biotech, Inc. 6 $134.41
Organon Llc 11 $122.08
Celltrion USA Inc. 1 $119.63
AIMMUNE THERAPEUTICS, INC. 6 $102.08
Lilly USA, LLC 4 $89.39
PFIZER INC. 3 $64.84
Boehringer Ingelheim Pharmaceuticals, Inc. 3 $58.71
Medtronic, Inc. 1 $24.90
Janssen Scientific Affairs, LLC 1 $22.56

By nature of payment

Food and Beverage
$2,196
Travel and Lodging
$1,243

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Themistocles Dassopoulos's medical specialty?
Dr. Themistocles Dassopoulos practices Gastroenterology Physician in Dallas, TX.
Where does Dr. Themistocles Dassopoulos practice?
Dr. Themistocles Dassopoulos practices at 3409 Worth Street, Dallas, TX 75246. Office phone: 4698007180.
What is Dr. Themistocles Dassopoulos's NPI?
Dr. Themistocles Dassopoulos's National Provider Identifier (NPI) is 1326083148, issued by NPPES.
Does Dr. Themistocles Dassopoulos accept Medicare assignment?
Yes. Dr. Themistocles Dassopoulos accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Themistocles Dassopoulos 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); Initial hospital care with straightforward or low level of medical decision making (HCPCS 99221). Source: CMS Medicare Physician & Other Practitioners file.