Colonoscopy clinicians in Tacoma, Washington
CMS lists 32 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 Tacoma, Washington (details below).
Colonoscopy volume
| Clinician | Colonoscopies billed | Percentile rank |
|---|---|---|
| Ajay Pabby, MD | 190 | 87% |
| Miguel Ordonez Castellanos, MD | 184 | 87% |
| Nicolas Villa Guillen, MD | 173 | 85% |
| Andrew Woolf, DO | 169 | 84% |
| Kalyan Kanneganti, MD | 166 | 84% |
| Steven Larson, MD | 161 | 82% |
| Kyung Noh, MD | 160 | 82% |
| Robert Lawson | 150 | 80% |
| Michael Lee, MD | 128 | 74% |
| John Sun, MD | 124 | 73% |
| William Holderman, MD | 120 | 71% |
| Charles Donner, MD | 105 | 66% |
| Amy Tsuchida, MD | 101 | 65% |
| Jennifer Higa, MD | 84 | 57% |
| Brian Mulhall, MD | 84 | 57% |
| Leonard Philo, MD | 83 | 57% |
| Patricia Ann Quaine, MD | 82 | 56% |
| Mark Potter, DO | 80 | 55% |
| Darren Schwartz, MD | 61 | 45% |
| Kawthar Mohamed, MD | 60 | 44% |
| Brittany Mitchell, MD | 56 | 42% |
| Asad Pervez, MD | 56 | 42% |
| Jeffrey Tokar, MD | 53 | 40% |
| Daniel Bushyhead, MD | 49 | 38% |
| Po-Hong Liu, MD | 46 | 36% |
| Sangik Oh, MD | 44 | 34% |
| Surosree Ganguli, MD | 37 | 30% |
| Pierre Nader, MD | 34 | 28% |
| Charles Scheurich, MD | 34 | 28% |
| Nicholas Procaccini, MD | 31 | 26% |
| Lillian Wang, MD | 31 | 26% |
| Pallavi Patel, 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.
Reported in previous releases
CMS does not report a colonoscopy volume for these clinicians in the October 2, 2026 release. Their pages show figures from earlier releases.
- Sanjay Agrawal, MD Last reported August 18, 2026
- Ralph Katsman, MD Last reported August 18, 2026
- Kyle Severinsen, MD Last reported August 18, 2026
- Gary Taubman, MD Last reported August 18, 2026
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).