Doctor profile · Federal record

Dr. Thomas Defer, MD

Internal Medicine Physician (CMS: Internal Medicine) · Saint Louis, MO

  • NPI 1023036464
  • Accepts Medicare
  • MIPS 79.3 / 100 · 2023
  • 37 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
4950 Childrens Pl, Dept Internal MED
Saint Louis, MO 631101000
(314) 362-5060
fax (314) 362-6959
Mailing address
Po Box 7412011
Chicago, IL 606742011

Credentials & registration

NPPES · NUCC
NPI registered
July 2006 — 20 yrs on file
Profile last updated
April 17, 2025
Year of graduation
1989 — 37 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
Missouri #R4N34
Medicaid
MO #203721238

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1023036464. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
281
Distinct HCPCS
6
Medicare allowed
$24,892
HCPCS Description Services Patients Avg allowed
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 83 30 $76
99214 Established patient office or other outpatient visit, 30-39 minutes 64 59 $95
99213 Established patient office or other outpatient visit, 20-29 minutes 60 56 $64
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 47 13 $117
99238 Hospital discharge day management, 30 minutes or less 15 15 $77
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 12 12 $172

In context: peer comparison

Among 216 peers in this city , average services per provider: 171. This provider delivers 1.6× the peer median.

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Thomas Defer's medical specialty?
Dr. Thomas Defer practices Internal Medicine Physician in Saint Louis, MO.
Where does Dr. Thomas Defer practice?
Dr. Thomas Defer practices at 4950 Childrens Pl, Saint Louis, MO 631101000. Office phone: 3143625060.
What is Dr. Thomas Defer's NPI?
Dr. Thomas Defer's National Provider Identifier (NPI) is 1023036464, issued by NPPES.
Does Dr. Thomas Defer accept Medicare assignment?
Yes. Dr. Thomas Defer accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Thomas Defer commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Established patient office or other outpatient visit (HCPCS 99214); Established patient office or other outpatient visit (HCPCS 99213). Source: CMS Medicare Physician & Other Practitioners file.