Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Emergency Medicine

Michael P. Zimmerman, MD

Works at hospitals in Round Rock, TX · Texas

Summary

Dr. Michael P. Zimmerman, MD is an emergency medicine doctor at 2400 Round Rock Ave, Round Rock, TX 78681. Phone: (512) 341-1000. Accepts Medicare assignment. In 2024, Michael P. Zimmerman had 50 Original Medicare patients and 61 services. NPI 1518909647. 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: Emergency medicine doctor (Medicare lists Emergency Medicine)
  • Address: 2400 Round Rock Ave, Round Rock, TX 78681 · Directions (1 more location)
  • Phone: (512) 341‑1000
  • Medicare: Accepts Medicare assignment
  • Hospital: Round Rock Medical Center
  • Group practice: Longhorn Emergency Medical Associates PA
  • Medical school: Loyola University Of Chicago, Stritch School Of Medicine · graduated 1999 (27 years since medical school)
  • Gender (as listed): Male

From official Medicare data

This page shows what Medicare's official clinician data says about Michael P. Zimmerman, 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 Michael P. Zimmerman accept Medicare assignment?
Yes. Medicare's clinician data says Michael P. Zimmerman 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 Michael P. Zimmerman see?
In 2024, CMS data shows 50 Original Medicare patients and 61 services for Michael P. Zimmerman. This counts Original Medicare only and measures volume, not quality.
What is Michael P. Zimmerman's NPI number?
1518909647. 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 Michael P. Zimmerman, 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 patients50
Services billed to Medicare61
Different services or procedures7
Participating Medicare providerYes
Average age of these patients74

Most frequent services

  1. Emergency department visit with moderate level of medical decision making (99284)22 services
  2. Emergency department visit with high level of medical decision making (99285)18 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 blood pressure75%
  • High cholesterol75%
  • Arthritis56%
  • Ischemic heart disease50%
  • Anxiety42%
  • Diabetes36%

Hospitals where Michael P. Zimmerman works

Medicare's Facility Affiliation Data lists Michael P. Zimmerman 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 Michael P. Zimmerman is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Michael P. Zimmerman as a member of this group (CMS data updated October 2, 2026).

  • Longhorn Emergency Medical Associates PA159 clinicians in the group

Specialties

Find other Emergency Medicine doctors in Texas →

Other emergency medicine doctors in Round Rock

Clinicians with the same Medicare primary specialty in Round Rock, TX — not a recommendation.

All emergency medicine doctors in Round Rock →

Other clinicians in Longhorn Emergency Medical Associates PA

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

Clinician information

CredentialMD
Medical schoolLoyola University Of Chicago, Stritch School Of Medicine
Graduation year1999 (27 years since medical school)
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1518909647
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