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Anesthesiology

William S. Mondzac, MD

Sees patients in Seattle, WA · Washington

Summary

Dr. William S. Mondzac, MD is an anesthesiologist at 1229 Madison St, Suite 1440, Seattle, WA 98104. Phone: (206) 625-0578. Accepts Medicare assignment. In 2024, William S. Mondzac had 11 Original Medicare patients and 12 services. NPI 1033262464. Source: CMS National Downloadable File, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

  • Specialty: Anesthesiologist (Medicare lists Anesthesiology)
  • Address: 1229 Madison St, Suite 1440, Seattle, WA 98104 · Directions
  • Phone: (206) 625‑0578
  • Medicare: Accepts Medicare assignment
  • Group practice: Physicians Anesthesia Service PLLC
  • Medical school: Georgetown University School Of Medicine · graduated 1987 (39 years since medical school)
  • Gender (as listed): Male

From official Medicare data

This page shows what Medicare's official clinician data says about William S. Mondzac, 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 William S. Mondzac accept Medicare assignment?
Yes. Medicare's clinician data says William S. Mondzac 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 William S. Mondzac see?
In 2024, CMS data shows 11 Original Medicare patients and 12 services for William S. Mondzac. This counts Original Medicare only and measures volume, not quality.
What is William S. Mondzac's NPI number?
1033262464. 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 William S. Mondzac, 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 patients11
Services billed to Medicare12
Different services or procedures9
Participating Medicare providerYes
Average age of these patients76

Practice locations

Addresses where William S. Mondzac is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists William S. Mondzac as a member of this group (CMS data updated October 2, 2026).

  • Physicians Anesthesia Service PLLC172 clinicians in the group

Specialties

Find other Anesthesiology doctors in Washington →

Other anesthesiologists in Seattle

Clinicians with the same Medicare primary specialty in Seattle, WA — not a recommendation.

All anesthesiologists in Seattle →

Other clinicians in Physicians Anesthesia Service PLLC

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

Clinician information

CredentialMD
Medical schoolGeorgetown University School Of Medicine
Graduation year1987 (39 years since medical school)
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1033262464
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. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  2. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians