Colonoscopy clinicians in Murrieta, California

CMS lists 39 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 Murrieta, California (details below).

Colonoscopy volume

Clinician	Colonoscopies billed	Percentile rank
Roxanne Lim, MD	562	99%
Philip Chen, MD	474	99%
Brian Lim, MD	430	99%
Kalpana Patel, MD	295	96%
Huafeng Shen, MD	285	95%
Alan Naim, MD	271	95%
Omar Shahbaz, MD	232	92%
Abbass Shafii, MD	191	87%
Saeid Goshtasbi, MD	170	84%
Diana Yao, MD	161	82%
Dhuha Alhankawi, MD	160	82%
Naishadh Raghuwanshi, MD	151	80%
Gustavo Machicado, MD	137	77%
Seyedehsan Navabi, MD	135	76%
Gregory Ardigo, MD	127	74%
Daniel Eshaghian, DO	124	73%
Mark Davidson, MD	120	71%
Vinod Mishra, MD	119	71%
Jack Dinh, MD	105	66%
Arian Teymoorian, MD	100	64%
Adebambo Ojuri, MD	98	63%
Liza Plafsky, MD	93	61%
Thomas Kemmerly, MD	89	59%
Scott Lee, MD	88	59%
James Hwang, MD	81	55%
Marco Paez, MD	78	54%
Christina Steinhauser, DO	78	54%
Galen Huang, MD	50	38%
Adnan Ameer, MD	45	35%
Jim Amerian, MD	45	35%
Erick Argueta, MD	39	31%
Adam Deising, DO	19	18%
Khaled Selim, MD	13	14%
Dalia Al-Mudallal, MD	1-10	13% or below
Taruna Bhatia, MD	1-10	13% or below
David Nguyen, MD	1-10	13% or below
Nghia Nguyen, MD	1-10	13% or below
John Pyne, MD	1-10	13% or below
Robert Wen, 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).