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Compare the published Medicare service mix of Glen S O'sullivan, M.D. with clinicians in the same registry specialty: Orthopedic Surgery (CMS).

CA · Exact areaEdit location

2024 published service data · 500 eligible profiles compared. This search reached its 500-profile comparison limit, using NPI order. Narrow the location for a more focused comparison. Similarity describes billing patterns, not quality, outcomes, or suitability for your care.

Randall W Armstrong, M.D.

Family Practice (CMS) · Sacramento, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • Injection of anesthetic and/or steroid drug into sacral spine nerve root using imaging guidance, each additional level (64484)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
60%Service-mix similarityView profile →

Ravi S Panjabi, MD

Anesthesiology (CMS) · Castro Valley, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Injection of anesthetic and/or steroid drug into sacral spine nerve root using imaging guidance, single level (64483)
59%Service-mix similarityView profile →

Michael Jay Hollander, M.D.

Orthopedic Surgery (CMS) · Encino, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Aspiration and/or injection of fluid from large joint (20610)
51%Service-mix similarityView profile →

R Scott Snyder, M.D.

General Surgery (CMS) · Castro Valley, CA

Shared published services
2 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
46%Service-mix similarityView profile →

Ning-Ai Liu, M.D.

Endocrinology · Internal Medicine (CMS) · Los Angeles, CA

Shared published services
2 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
45%Service-mix similarityView profile →

Niall E Roche

Rheumatology (CMS) · Pleasanton, CA

Shared published services
2 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
45%Service-mix similarityView profile →

Lilly F Ramirez-Boyd, M.D.

Specialty details in registry · Orange, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more (99205)
  • Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)
44%Service-mix similarityView profile →

Kevin Karlye Howe, M.D.

Orthopedic Surgery (CMS) · Santa Rosa, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Aspiration and/or injection of fluid from large joint (20610)
43%Service-mix similarityView profile →

Tony Frazer Feuerman, M.D.

Neurosurgery (CMS) · Encino, CA

Shared published services
2 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more (99205)
43%Service-mix similarityView profile →

Peter Nicholas Sfakianos, M.D.

Orthopedic Surgery (CMS) · Folsom, CA

Shared published services
2 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • Aspiration and/or injection of fluid from large joint (20610)
42%Service-mix similarityView profile →

Scott Gordon Kantor, M.D.

Orthopedic Surgery (CMS) · Monterey, CA

Shared published services
3 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Aspiration and/or injection of fluid from large joint (20610)
42%Service-mix similarityView profile →

Dorothy J. Buckner, M.D.

Dermatology (CMS) · Los Gatos, CA

Shared published services
2 shared services · view billing descriptions
  • Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
42%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.