Colonoscopy clinicians in Olney, Maryland
CMS lists 27 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 Olney, Maryland (details below).
Colonoscopy volume
| Clinician | Colonoscopies billed | Percentile rank |
|---|---|---|
| Michael Schindler, MD | 163 | 83% |
| Robert Finkel, MD | 160 | 82% |
| Rudrajit Rai, MD | 156 | 81% |
| Joshua Rosenbloom, DO | 145 | 79% |
| Stephen Humm, MD | 126 | 73% |
| Marc Kozam, MD | 118 | 70% |
| Alexander Mamunes, MD | 118 | 70% |
| Zaifi Shanavas, MD | 116 | 70% |
| Nissrin Ezmerli, MD | 102 | 65% |
| Dabo Xu, MD | 102 | 65% |
| Neil Julie, MD | 100 | 64% |
| Eduardo Castillo Del Castillo, MD | 92 | 61% |
| Ruben Acosta, MD | 89 | 59% |
| Akriti Saxena, MD | 88 | 59% |
| Joseph Genovese, MD | 75 | 52% |
| Roderick Kreisberg, MD | 60 | 45% |
| Dhruv Lowe, MD | 54 | 41% |
| Shaffer Mok, MD | 54 | 41% |
| Farzin Rashti, MD | 53 | 41% |
| Eric Margulies, MD | 42 | 34% |
| Urooj Ahmed, MD | 41 | 33% |
| Thi Khuc, MD | 41 | 33% |
| Monica Passi, MD | 37 | 31% |
| Pia Prakash, MD | 36 | 30% |
| Rushi Talati, MD | 21 | 20% |
| Robert Byrne | 20 | 19% |
| Jennie Zhang, DO | 12 | 14% |
Sorted by the number of colonoscopies billed to Medicare, highest first, not by quality or skill.
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 (August 18, 2026 release).