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Anesthesiology

Orestes Y. Mavrothalassitis, MD

Works at hospitals in San Francisco, CA · California

Summary

Dr. Orestes Y. Mavrothalassitis, MD is an anesthesiologist at 1600 Divisadero St, San Francisco, CA 94115. Phone: (415) 476-1000. Accepts Medicare assignment. In 2024, Orestes Y. Mavrothalassitis had 76 Original Medicare patients and 85 services. NPI 1265937205. 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: 1600 Divisadero St, San Francisco, CA 94115 · Directions (1 more location)
  • Phone: (415) 476‑1000
  • Medicare: Accepts Medicare assignment
  • Hospitals: UCSF Health Stanyan Hospital, UCSF Medical Center
  • Group practice: University Anesthesia Medical Group
  • Medical school: University Of Maryland School Of Medicine · graduated 2018 (8 years since medical school)
  • Gender (as listed): Male

From official Medicare data

This page shows what Medicare's official clinician data says about Orestes Y. Mavrothalassitis, 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 Orestes Y. Mavrothalassitis accept Medicare assignment?
Yes. Medicare's clinician data says Orestes Y. Mavrothalassitis 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 Orestes Y. Mavrothalassitis see?
In 2024, CMS data shows 76 Original Medicare patients and 85 services for Orestes Y. Mavrothalassitis. This counts Original Medicare only and measures volume, not quality.
What is Orestes Y. Mavrothalassitis's NPI number?
1265937205. 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 Orestes Y. Mavrothalassitis, 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 patients76
Services billed to Medicare85
Different services or procedures41
Participating Medicare providerYes
Average age of these patients73

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%
  • Diabetes49%
  • Arthritis49%
  • Chronic kidney disease42%
  • Depression34%

Hospitals where Orestes Y. Mavrothalassitis works

Medicare's Facility Affiliation Data lists Orestes Y. Mavrothalassitis 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 Orestes Y. Mavrothalassitis is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Orestes Y. Mavrothalassitis as a member of this group (CMS data updated October 2, 2026).

  • University Anesthesia Medical Group408 clinicians in the group

Specialties

Find other Anesthesiology doctors in California →

Other anesthesiologists in San Francisco

Clinicians with the same Medicare primary specialty in San Francisco, CA — not a recommendation.

All anesthesiologists in San Francisco →

Other clinicians in University Anesthesia Medical Group

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

Clinician information

CredentialMD
Medical schoolUniversity Of Maryland School Of Medicine
Graduation year2018 (8 years since medical school)
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1265937205
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