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Obstetrics/Gynecology

Thomas M. Kazmierczak Jr., DO

Works at hospitals in New Lenox, IL · Illinois

Summary

Dr. Thomas M. Kazmierczak Jr., DO is an OB-GYN at 2100 Glenwood Ave, Joliet, IL 60435. Phone: (815) 725-2121. Accepts Medicare assignment. In 2024, Thomas M. Kazmierczak Jr. had 30 Original Medicare patients and 53 services. NPI 1225033871. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

  • Specialty: OB-GYN (Medicare lists Obstetrics/Gynecology)
  • Address: 2100 Glenwood Ave, Joliet, IL 60435 · Directions (1 more location)
  • Phone: (815) 725‑2121
  • Medicare: Accepts Medicare assignment
  • Hospital: Silver Cross Hospital and Medical Centers
  • Group practice: Dupage Medical Group Ltd
  • Medical school: graduated 2000 (26 years since medical school)
  • Gender (as listed): Male

From official Medicare data

This page shows what Medicare's official clinician data says about Thomas M. Kazmierczak Jr., joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Thomas M. Kazmierczak Jr. accept Medicare assignment?
Yes. Medicare's clinician data says Thomas M. Kazmierczak Jr. accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
How many Medicare patients does Thomas M. Kazmierczak Jr. see?
In 2024, CMS data shows 30 Original Medicare patients and 53 services for Thomas M. Kazmierczak Jr.. This counts Original Medicare only and measures volume, not quality.
What is Thomas M. Kazmierczak Jr.'s NPI number?
1225033871. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Medicare activity in 2024

Official CMS public-use data for Thomas M. Kazmierczak Jr., data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Original Medicare patients30
Services billed to Medicare53
Different services or procedures14
Participating Medicare providerYes
Average age of these patients70

Most frequent services

  1. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)24 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

  • High cholesterol75%
  • High blood pressure50%
  • Arthritis37%
  • Anxiety37%

Hospitals where Thomas M. Kazmierczak Jr. works

Medicare's Facility Affiliation Data lists Thomas M. Kazmierczak Jr. at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

Practice locations

Addresses where Thomas M. Kazmierczak Jr. is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Thomas M. Kazmierczak Jr. as a member of this group (CMS data updated October 2, 2026).

  • Dupage Medical Group Ltd1,322 clinicians in the group

Specialties

Find other Obstetrics/Gynecology doctors in Illinois →

Other OB-GYNs in Joliet

Clinicians with the same Medicare primary specialty in Joliet, IL — not a recommendation.

All OB-GYNs in Joliet →

Other clinicians in Dupage Medical Group Ltd

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialDO
Graduation year2000 (26 years since medical school)
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1225033871
CorrectionsReport an error or suggest an update →

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
  2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
  3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  6. Medicare Care Compare — official Medicare tool to look up clinicians