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Compare the published Medicare service mix of Zachary Daniel Preefer, DO with clinicians in the same registry specialty: Anesthesiology.

SAN JOSE, CA · Exact areaEdit location

2024 published service data · 45 eligible profiles compared. Similarity describes billing patterns, not quality, outcomes, or suitability for your care.

Steven Naleway, MD

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
100%Service-mix similarityView profile →

Richard Chiang, MD

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
100%Service-mix similarityView profile →

Florence Lin, M.D.

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
100%Service-mix similarityView profile →

Bobby John Mathew, MD

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
74%Service-mix similarityView profile →

Mark Allen Jamieson, MD

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
74%Service-mix similarityView profile →

Paul Byron Kennedy, MD

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
71%Service-mix similarityView profile →

Audrey Lee

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
69%Service-mix similarityView profile →

Johnathan P. Pak, M.D.

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
65%Service-mix similarityView profile →

Chia-Bing Chang, M.D

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
63%Service-mix similarityView profile →

Cynthia Siu-San Yuan, MD

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
63%Service-mix similarityView profile →

John Bret Cellar, MD

Anesthesiology · San Jose, CA

Shared published services
1 shared services · view billing descriptions
  • Anesthesia for lens surgery (00142)
61%Service-mix similarityView profile →
How this comparison works

We use the same calendar year of CMS Medicare Physician & Other Practitioners data for both providers. Published non-drug service counts are combined by HCPCS code across places of service. We apply log(1 + count), normalize the vectors, and compare them using cosine similarity.

Candidates share the reference provider’s current NPPES primary taxonomy and match the location you enter. We examine up to 500 candidates in NPI order, then show up to 12 with the highest positive similarity within that set. The score is not a percentile, medical recommendation, or prediction. Suppressed services are not estimated. Medicare fee-for-service data does not describe a provider’s entire practice.

Source: CMS Medicare Physician & Other Practitioners - by Provider and Service : 2024-12-01 · Published May 21, 2026.