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Diagnostic Radiology

John F. Hamer, MD

Works at hospitals in Menomonee Falls, WI · New Berlin, WI · Milwaukee, WI … · Wisconsin

Summary

Dr. John F. Hamer, MD is a radiologist at 1155 N Mayfair Rd, Wauwatosa, WI 53226. Phone: (414) 955-5990. Accepts Medicare assignment. In 2024, John F. Hamer had 783 Original Medicare patients and 1,353 services. NPI 1093763864. 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.

From official Medicare data

This page shows what Medicare's official clinician data says about John F. Hamer, 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 John F. Hamer accept Medicare assignment?
Yes. Medicare's clinician data says John F. Hamer 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 John F. Hamer see?
In 2024, CMS data shows 783 Original Medicare patients and 1,353 services for John F. Hamer. This counts Original Medicare only and measures volume, not quality.
What is John F. Hamer's NPI number?
1093763864. 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 John F. Hamer, 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 patients783
Services billed to Medicare1,353
Different services or procedures64
Participating Medicare providerYes
Average age of these patients74

Most frequent services

  1. Ct scan head or brain without contrast (70450)233 services
  2. Mri scan of brain without contrast (70551)175 services
  3. Screening 3d breast mammography (77063)156 services
  4. Screening mammography (77067)156 services
  5. Ct scan of upper spine without contrast (72125)76 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 pressure74%
  • Arthritis49%
  • Anxiety35%
  • Depression32%
  • Ischemic heart disease31%

Hospitals where John F. Hamer works

Medicare's Facility Affiliation Data lists John F. Hamer 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 John F. Hamer is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 20; the Medicare profile lists all.

Group practices

Medicare enrollment lists John F. Hamer as a member of these groups (CMS data updated October 2, 2026).

  • The Medical College of Wisconsin Inc2,115 clinicians in the group
  • Froedtert Andthe Medical College of Wisconsin Community Physicians Inc1,285 clinicians in the group

Specialties

Find other Diagnostic Radiology doctors in Wisconsin →

Other radiologists in Wauwatosa

Clinicians with the same Medicare primary specialty in Wauwatosa, WI — not a recommendation.

All radiologists in Wauwatosa →

Other clinicians in The Medical College of Wisconsin Inc

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

Clinician information

CredentialMD
Medical schoolMedical College Of Wisconsin
Graduation year1999 (27 years since medical school)
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1093763864
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