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Anesthesiology

Ashley M. Tollefson, MD

Works at hospitals in Kirkland, WA · Washington

Summary

Dr. Ashley M. Tollefson, MD is an anesthesiologist at 1035 116th Ave NE, Bellevue, WA 98004. Phone: (425) 688-5000. Accepts Medicare assignment. In 2024, Ashley M. Tollefson had 61 Original Medicare patients and 80 services. NPI 1891228508. 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: Anesthesiologist (Medicare lists Anesthesiology)
  • Address: 1035 116th Ave NE, Bellevue, WA 98004 · Directions
  • Phone: (425) 688‑5000
  • Medicare: Accepts Medicare assignment
  • Hospital: Evergreenhealth Medical Center
  • Group practice: Matrix Anesthesia, PS
  • Medical school: University Of Minnesota Medical School · graduated 2017 (9 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Ashley M. Tollefson, 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 Ashley M. Tollefson accept Medicare assignment?
Yes. Medicare's clinician data says Ashley M. Tollefson 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 Ashley M. Tollefson see?
In 2024, CMS data shows 61 Original Medicare patients and 80 services for Ashley M. Tollefson. This counts Original Medicare only and measures volume, not quality.
What is Ashley M. Tollefson's NPI number?
1891228508. 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 Ashley M. Tollefson, 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 patients61
Services billed to Medicare80
Different services or procedures35
Participating Medicare providerYes
Average age of these patients74

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%
  • Arthritis62%
  • Ischemic heart disease36%
  • Anxiety26%
  • Diabetes25%

Hospitals where Ashley M. Tollefson works

Medicare's Facility Affiliation Data lists Ashley M. Tollefson 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 Ashley M. Tollefson is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

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

  • Matrix Anesthesia, PS88 clinicians in the group

Specialties

Find other Anesthesiology doctors in Washington →

Other anesthesiologists in Bellevue

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

All anesthesiologists in Bellevue →

Other clinicians in Matrix Anesthesia, PS

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

Clinician information

CredentialMD
Medical schoolUniversity Of Minnesota Medical School
Graduation year2017 (9 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1891228508
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