Doctor profile · Federal record

Dr. Thomas Hemmen, M.D./PH.D

Vascular Neurology Physician (CMS: Neuropsychiatry) · Neurology Physician · San Diego, CA

  • NPI 1902821945
  • Accepts Medicare
  • 32 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

Operates at 3 locations .

NPPES Updated May 11, 2026
Primary practice
200 W Arbor Dr
San Diego, CA 921039000
(800) 926-8273
fax (888) 539-8781
Additional location
6655 Alvarado RD
San Diego, CA 921205208
Additional location
9350 Campus Point Dr
La Jolla, CA 920371300
Mailing address
File 57326
Los Angeles, CA 900747326

Credentials & registration

NPPES · NUCC
NPI registered
July 2006 — 20 yrs on file
Profile last updated
July 23, 2024
Year of graduation
1994 — 32 yrs since
Specialty taxonomy
2084V0102X — NUCC code
State license (1)
California #A72645
Medicaid
CA #00A726450

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1902821945. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
249
Distinct HCPCS
6
Medicare allowed
$33,516
HCPCS Description Services Patients Avg allowed
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 117 62 $123
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 74 72 $179
99214 Established patient office or other outpatient visit, 30-39 minutes 19 19 $101
99213 Established patient office or other outpatient visit, 20-29 minutes 14 13 $68
99215 Established patient office or other outpatient visit, 40-54 minutes 13 13 $149
99203 New patient office or other outpatient visit, 30-44 minutes 12 12 $85

In context: peer comparison

Among 2 peers in San Diego Vascular Neurology Physician, average services per provider: 60. This provider delivers 4.2× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$33
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Genentech USA, INC. 1 $33.33

By nature of payment

Food and Beverage
$33

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Thomas Hemmen's medical specialty?
Dr. Thomas Hemmen practices Vascular Neurology Physician in San Diego, CA.
Where does Dr. Thomas Hemmen practice?
Dr. Thomas Hemmen practices at 200 W Arbor Dr, San Diego, CA 921039000. Office phone: 8009268273.
What is Dr. Thomas Hemmen's NPI?
Dr. Thomas Hemmen's National Provider Identifier (NPI) is 1902821945, issued by NPPES.
Does Dr. Thomas Hemmen accept Medicare assignment?
Yes. Dr. Thomas Hemmen accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Thomas Hemmen commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Initial hospital care with moderate level of medical decision making (HCPCS 99223); Established patient office or other outpatient visit (HCPCS 99214). Source: CMS Medicare Physician & Other Practitioners file.