Colonoscopy clinicians in Madison, Wisconsin

CMS lists 42 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 Madison, Wisconsin (details below).

Colonoscopy volume

Clinician	Colonoscopies billed	Percentile rank
Michael Allan, MD	206	89%
Geoffrey Dang-Vu, MD	187	87%
Jason Gonzaga, MD	184	87%
Alexander Lee, MD	176	85%
Abby Lochmann-Bailkey, MD	176	85%
Antonio Bosch, MD	172	85%
John Williams, MD	167	84%
Alexander Larson, MD	149	80%
Siobhan Byrne, MD	125	73%
Andrew Walker, MD	123	72%
Naree Whang, MD	118	71%
Anurag Soni, MD	117	70%
Peter Stadmeyer, MD	100	64%
Patrick Pfau, MD	96	63%
Bryan Magenheim, MD	90	60%
Kevin Patel, MD	89	59%
Rodrigo Castillo, MD	81	55%
Freddy Caldera, DO	79	54%
Kerstin Austin, MD	66	47%
Eric Gaumnitz, MD	63	46%
Megan Lutz, MD	60	44%
Sumona Saha, MD	59	44%
Ian Grimes, MD	56	42%
Andrew Spiel, MD	56	42%
Mark Benson, MD	54	41%
Christopher Lindholm, MD	50	38%
Margarita German, MD	38	30%
Derek Hubbard, MD	38	30%
Luis Lomeli, MD	36	29%
Deepak Gopal, MD	35	28%
Gabriela Lobato, MD	29	25%
Gary Griglione, MD	27	23%
Vinay Patel, MD	27	23%
Jennifer Weiss, MD	25	22%
Nicole Boschuetz, MD	23	21%
Adnan Said, MD	23	21%
Mansoor Shariff, MD	21	20%
Lisa Strate, MD	20	19%
Praveena Narayanan, MD	17	17%
Anne Kolan, MD	1-10	13% or below
Jessica Musto, MD	1-10	13% or below
Paulina Phillips, 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).