Colonoscopy clinicians in Torrance, California

CMS lists 40 clinicians with a primary specialty of Gastroenterology, Internal Medicine, Family Practice, or General Practice who have billed Medicare for at least one colonoscopy and practice in Torrance, California (details below).

Colonoscopy volume

Clinician	Colonoscopies billed	Percentile rank
David Kim, MD	244	93%
James Sattler, MD	237	92%
Jerome Cohen, MD	208	90%
Karl Fukunaga, MD	165	83%
Oren Zaidel, MD	159	82%
Tonny Lee, MD	154	81%
Gloria Sze, MD	151	80%
John Kasher, MD	139	77%
Waleed Shindy, MD	131	75%
Daniel Cho, MD	127	74%
Minh Nguyen, MD	117	70%
Chirag Patel, MD	114	69%
Robert Webman, MD	111	68%
Azam Riyaz, MD	105	66%
David Chung, MD	103	65%
Timothy Tran, MD	102	65%
James Kao, MD	95	62%
Wei-Chung Chen, MD	89	59%
Robert Mecum, MD	89	59%
Shahina Hakim, MD	87	59%
Alexander Nguyen, MD	85	58%
John Zeroogian, MD	79	54%
Thai Ha, MD	77	53%
Chun Hsu, MD	75	52%
Adrienne Lenhart, MD	65	47%
Daniel Shue, MD	63	46%
Bao Sean Nguyen, MD	62	45%
Sonya Dasharathy, MD	57	42%
Melissa Munsell, MD	52	40%
Didi Mwengela, MD	51	39%
Ellie Chen, MD	49	38%
Kelsey Collins, MD	48	37%
Nazir Khaja, MD	46	36%
Jennifer Kolb, MD	41	32%
Nimah Ather, MD	34	28%
Fouzia Oza, MD	23	21%
Sutha Sachar, MD	22	20%
Kenneth Holt, MD	13	14%
Viktor Eysselein, MD	1-10	13% or below
Marcil Mamita, MD	1-10	13% or below

Sorted by the number of colonoscopies 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 "Colonoscopy" category combines specific billing codes for colonoscopy to calculate the number of times each clinician billed Medicare for a "Colonoscopy." These include screening colonoscopy, diagnostic colonoscopy, and colonoscopy with biopsy or polyp removal. CMS's list also includes flexible sigmoidoscopy and laparoscopic appendectomy, so a clinician's count may include those procedures. CMS counts one procedure per patient per day, so a colonoscopy that included both a biopsy and a polyp removal counts once. 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 colonoscopies a clinician performed during the reporting period. Lastly, only clinicians with a primary specialty of Gastroenterology, Internal Medicine, Family Practice, or General Practice (as reported to Medicare) are presented.

Source: Centers for Medicare & Medicaid Services (October 2, 2026 release).