Dr. Guy A. Weiss, M.D.
Gastroenterology (Gastroenterology Physician)
462 Grider St, Internal Medicine Residency Training Program
Buffalo, NY 14215
- Medicare participating
At a glance
- Years since graduation
- 16
- In the NPI registry since
- 2010
- Medicare patients seen, 2024
- 407
Licensed in California since 2013, according to the Medical Board of California. We show license dates only for the states that publish them in bulk; see which states do. For other states, check the state medical board.
The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. What an NPI is
Education and training
- 2010Registered with an NPI (national billing number; not a license date)
Medicare’s Care Compare data doesn’t list this clinician’s medical school. Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).
Specialties and state licenses
-
Gastroenterology Physician primary
CA license A125480 (first issued 2013; current) - Student in an Organized Health Care Education/Training Program
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- Ronald Reagan UCLA Medical Center Los Angeles, CA
- Santa Monica - UCLA Med Ctr & Orthopaedic Hospital Santa Monica, CA
Medical groups
- The Regents of the University of California (1,462 clinicians)
Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.
Medicare patients and services
- Medicare patients, 2024
- 407
- Services billed
- 966
- Patients’ average age
- 71
| Service | Times | Patients |
|---|---|---|
| New patient office or other outpatient visit, 45-59 minutes | 100 | 100 |
| Established patient office or other outpatient visit, 30-39 minutes | 91 | 73 |
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | 80 | 77 |
| Biopsy of large bowel using a flexible endoscope | 78 | 77 |
| Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 51 | 33 |
| Established patient office or other outpatient visit, 40-54 minutes | 36 | 35 |
| Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes | 35 | 35 |
| Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | 18 | 16 |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | 18 | 18 |
| Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | 18 | 18 |
Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.
Medicare prescriptions
| Drug | Prescriptions |
|---|---|
| Linzess (linaclotide) Other prescribers in Buffalo, NY | 105 |
| Gavilyte-C (peg3350/sod sulf,bicarb,cl/kcl) Other prescribers in Buffalo, NY | 61 |
| Motegrity (prucalopride succinate) | 61 |
| Omeprazole Other prescribers in Buffalo, NY | 57 |
| Pantoprazole Sodium Other prescribers in Buffalo, NY | 47 |
| Mesalamine Other prescribers in Buffalo, NY | 23 |
| Famotidine Other prescribers in Buffalo, NY | 17 |
| Esomeprazole Magnesium Other prescribers in Buffalo, NY | 16 |
| Xifaxan (rifaximin) Other prescribers in Buffalo, NY | 11 |
| Trulance (plecanatide) | 11 |
Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.
Payments from drug and device companies
In 2025, 4 companies reported 14 payments worth $649 in total to this clinician.
| Genzyme Corporation | $339 |
|---|---|
| Ardelyx, Inc. | $169 |
| AbbVie Inc. | $126 |
| Regeneron Pharmaceuticals, Inc. | $14.76 |
| Food and Beverage | $649 |
|---|
From CMS Open Payments. A payment is not evidence of wrongdoing; many are for consulting, teaching or meals. Clinicians can review and dispute their records with CMS.
Industry-funded research
Named as a principal investigator on 1 industry-funded study in 2025, from 1 company. The companies reported $28,555 in research payments for these studies, mostly to the institutions running them.
- A Study to Learn How Well Dupilumab Works in Adult and Adolescent Participants With Eosinophilic Gastritis With or Without Eosinophilic Duodenitis and the Side Effects it May Have
Regeneron Pharmaceuticals, Inc. · Active, not recruiting · NCT05831176
From CMS Open Payments research payments, where companies name up to five principal investigators per payment. Research payments usually go to hospitals, universities and research sites, not to the investigator personally. A payment is not evidence of wrongdoing.