Mohs surgery clinicians in Walnut Creek, California
CMS lists 16 clinicians with a primary specialty of dermatology, micrographic dermatologic surgery, plastic and reconstructive surgery, otolaryngology, ophthalmology, general surgery, hand surgery, or surgical oncology who have billed Medicare for at least one removal of skin cancer procedure and practice in Walnut Creek, California (details below).
Mohs surgery volume
| Clinician | Removal of skin cancer procedures billed | Percentile rank |
|---|---|---|
| Gregory Bricca, MD | 2,311 | 99% |
| Minh Dang, MD | 1,335 | 93% |
| Hovik Ashchyan, MD | 1,091 | 89% |
| Hina Ahmad, MD | 857 | 81% |
| Anne Zhuang, MD | 685 | 72% |
| Jeffrey Bortz, MD | 643 | 70% |
| Abdallah Khourdaji, MD | 424 | 54% |
| David No, MD | 408 | 53% |
| Carie Chui, MD | 309 | 43% |
| Stefanie Altmann, DO | 298 | 42% |
| Grace Sohn, MD | 253 | 38% |
| Alexandra Vaughn, MD | 140 | 26% |
| Jane Kardashian, MD | 112 | 22% |
| Andrew Menkes, MD | 104 | 21% |
| Ji Won Ahn, MD | 1-10 | 8% or below |
| Ricardo Guerra, MD | 1-10 | 8% or below |
Sorted by the number of removal of skin cancer procedures billed to Medicare, highest first, not by quality or skill. CMS suppresses counts between 1 and 10 to protect patient privacy and publishes the range instead.
Understanding CMS Data
CMS's "Removal of skin cancer" category combines specific billing codes for Mohs micrographic surgery to calculate the number of times each clinician billed Medicare for "Removal of skin cancer." In Mohs surgery, the clinician removes a skin cancer in stages and examines each stage under a microscope during the same visit. CMS counts each billing code separately, so a single skin cancer that takes more than one stage can contribute more than once to this total. CMS reports removal of a skin cancer by standard excision, without microscopic examination during the visit, in a different category, so this total does not include it. CMS reports only procedures that clinicians billed to Original Medicare and Medicare Advantage. Therefore, CMS's procedure volume data does not include procedures that clinicians may have performed on patients who have other health care coverage (e.g., commercial insurance, self-pay, or the VA). Billing variation and coding errors can also affect CMS's data. Therefore, the number of procedures that CMS reports for a clinician may be higher or lower than the actual number of removal of skin cancer procedures a clinician performed during the reporting period. Lastly, only clinicians with a primary specialty of dermatology, micrographic dermatologic surgery, plastic and reconstructive surgery, otolaryngology, ophthalmology, general surgery, hand surgery, or surgical oncology (as reported to Medicare) are presented.
Source: Centers for Medicare & Medicaid Services (August 18, 2026 release).