HCPList Know more before you call. About
A DIFFERENT WAY TO EXPLORE

Similar work.
More providers to explore.

Compare the published Medicare service mix of Aaron Clark, MD, PHD with clinicians in the same registry specialty: Neurosurgery (CMS).

SAN FRANCISCO, CA · Exact areaEdit location

2024 published service data · 43 eligible profiles compared. Similarity describes billing patterns, not quality, outcomes, or suitability for your care.

Lee A Tan, M.D.

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
77%Service-mix similarityView profile →

Christopher P. Ames, MD

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
73%Service-mix similarityView profile →

Praveen V. Mummaneni, M.D.

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • Partial removal of spine bone with release of spinal cord and/or nerves, each additional segment (63048)
  • Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)
71%Service-mix similarityView profile →

Nima Alan, M.D.

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
68%Service-mix similarityView profile →

Leslie Christine Robinson, MD, PHARMD, MBA

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
65%Service-mix similarityView profile →

Marc Andrew Prablek, MD

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
58%Service-mix similarityView profile →

Nathan Byoungjun Han, MD

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
56%Service-mix similarityView profile →

Hesham Mostafa Zakaria, MD

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
54%Service-mix similarityView profile →

Tarun Arora, MD

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
54%Service-mix similarityView profile →

Timothy Chryssikos, MD

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
  • Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)
54%Service-mix similarityView profile →

Samer Zammar, M.D.

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)
51%Service-mix similarityView profile →

John Burke, MD

Neurosurgery (CMS) · San Francisco, CA

Shared published services
3 shared services · view billing descriptions
  • Fusion of additional segment of spine (22614)
  • New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)
  • Insertion of cage or mesh device to spine bone and disc space during spine fusion (22853)
48%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.