DR. THOMAS MICHAEL DEFER MD
NPI 1023036464
Internal Medicine in Saint Louis, MO

Active since July 17, 2006PECOS EnrolledAccepts Medicare Assignment
79.29/100
CMS Quality Rating
4950 CHILDRENS PL, DEPT INTERNAL MED, SAINT LOUIS, MO 63110(314) 362-5060(314) 362-6959 Get Directions Write a Review

NPPES record last updated: April 17, 2025. Verified against the NPPES registry weekly; last sync: August 16, 2026.

Record update history: Apr 25, 2024, Apr 10, 2024, Nov 15, 2021 and 2 more (5 updates tracked since 2016).

About Dr. Thomas Michael Defer Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. THOMAS MICHAEL DEFER MD (NPI 1023036464) is an individual internal medicine provider in Saint Louis, Missouri, licensed in Missouri (R4N34) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS, is affiliated with Barnes Jewish Hospital, and is a graduate of University Of Missouri, Columbia School Of Medicine (1989).

NPPES Registry Identity

NPI1023036464
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameDR. THOMAS MICHAEL DEFERCredential: MD
Location Address4950 CHILDRENS PL, DEPT INTERNAL MEDSaint Louis, MO 63110-1000
Mailing AddressPo Box 7412011Chicago, IL 60674-2011 · (314) 362-5060 · Fax (314) 362-6959
Fax(314) 362-6959
Sole ProprietorNo
Medical School CMSUniversity Of Missouri, Columbia School Of MedicineGraduated 1989
Enumeration DateJuly 17, 2006
Last NPPES UpdateApril 17, 20255 updates tracked since enumeration
NPI 1023036464 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License Licensed in MO · R4N34
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
4950 CHILDRENS PL, Saint Louis, MO 63110

Other Identifiers 1

Medicaid203721238MO

Accepted Insurance

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

Enrolled in Medicare and accepts Medicare assignment

Dr. Thomas Michael Defer Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID446395024
PECOS Enrollment IDI20100308000153
Eligible to Order & Refer Part B Labs & Imaging Durable Medical Equipment Home Health Agency Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 2

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213
This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.
86 services76 patients
Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
17 services17 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Barnes Jewish Hospital

Acute Care Hospitals · Saint Louis, MO
4/5 CMS rating
OwnershipVoluntary non-profit - Other
CMS Certification Number260032
LocationOne Barnes-Jewish Hospital PlazaSaint Louis, MO 63110 · St. Louis City County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 63110 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$128.28 typical visit price
range $55.65 – $169.38
Typical copayment $32.07 (range $13.91 – $42.34)
Most-billed visit code 99204
Established Patient
$98.37 typical visit price
range $17.76 – $137.92
Typical copayment $24.59 (range $4.44 – $34.48)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

79.29/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored as part of a group practice
Quality71.46
Promoting Interoperability100
Improvement Activities40
Cost59.51

Other Providers at the Same Location NPPES 12

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

General Practice
4950 CHILDRENS PL, DEPT INTERNAL MED
SAINT LOUIS, MO 63110
General Practice
4950 CHILDRENS PL, WOHL MEDICINE CLINIC 5TH FL
SAINT LOUIS, MO 63110
Family Medicine
4950 CHILDRENS PL
SAINT LOUIS, MO 63110
Internal Medicine
4950 CHILDRENS PL, DIV IM GEN MED, WOHL CLINIC 5TH FL
SAINT LOUIS, MO 63110
Dietitian, Registered
4950 CHILDRENS PL, DIV IM NEPHROLOGY
SAINT LOUIS, MO 63110
Internal Medicine
4950 CHILDRENS PL
SAINT LOUIS, MO 63110
Internal Medicine
4950 CHILDRENS PL, DEPT INTERNAL MED
SAINT LOUIS, MO 63110
Internal Medicine
4950 CHILDRENS PL, DEPT INTERNAL MED
SAINT LOUIS, MO 63110

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Thomas Defer's NPI number?

The NPI number for Thomas Defer is 1023036464. It was assigned to this individual provider in the NPPES registry on July 17, 2006.

Where is Thomas Defer located?

Thomas Defer practices at 4950 Childrens Pl Dept Internal Med, Saint Louis, MO 63110. The listed phone number is (314) 362-5060.

What is Thomas Defer's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Thomas Defer enrolled in Medicare?

Yes. Thomas Defer is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

What insurance does Thomas Defer accept?

Health plans from Cox HealthPlans list Thomas Defer as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Thomas Defer affiliated with any hospitals?

According to CMS data, Thomas Defer is affiliated with Barnes Jewish Hospital.

When was this NPI record last updated?

The NPPES record for Thomas Defer was last updated on April 17, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.