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Emergency Medicine

Chao A. Yuan, MD

Works at hospitals in Greenbrae, CA · California

Summary

Dr. Chao A. Yuan, MD is an emergency medicine doctor at 250 Bon Air Rd, Greenbrae, CA 94904. Phone: (415) 925-7000. Accepts Medicare assignment. In 2024, Chao A. Yuan had 481 Original Medicare patients and 841 services. NPI 1851617906. 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: 250 Bon Air Rd, Greenbrae, CA 94904 · Directions
  • Phone: (415) 925‑7000
  • Medicare: Accepts Medicare assignment
  • Hospital: Marinhealth Medical Center
  • Group practice: Cep America - California
  • Medical school: graduated 2006 (20 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Chao A. Yuan, 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 Chao A. Yuan accept Medicare assignment?
Yes. Medicare's clinician data says Chao A. Yuan 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 Chao A. Yuan see?
In 2024, CMS data shows 481 Original Medicare patients and 841 services for Chao A. Yuan. This counts Original Medicare only and measures volume, not quality.
What is Chao A. Yuan's NPI number?
1851617906. 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 Chao A. Yuan, 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 patients481
Services billed to Medicare841
Different services or procedures23
Participating Medicare providerYes
Average age of these patients78

Most frequent services

  1. Emergency department visit with high level of medical decision making (99285)354 services
  2. Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (93010)283 services
  3. Emergency department visit with moderate level of medical decision making (99284)91 services
  4. Critical care, first 30-74 minutes (99291)40 services
  5. X-ray of chest, 1 view (71045)29 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%
  • Arthritis54%
  • Anxiety39%
  • Ischemic heart disease38%
  • Depression31%

Hospitals where Chao A. Yuan works

Medicare's Facility Affiliation Data lists Chao A. Yuan 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.

  • Marinhealth Medical CenterGreenbrae, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050360

Practice locations

Addresses where Chao A. Yuan is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Chao A. Yuan as a member of this group (CMS data updated October 2, 2026).

  • Cep America - California1,292 clinicians in the group

Specialties

Find other Emergency Medicine doctors in California →

Other emergency medicine doctors in Greenbrae

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

All emergency medicine doctors in Greenbrae →

Other clinicians in Cep America - California

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

Clinician information

CredentialMD
Graduation year2006 (20 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1851617906
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