Dr. Chester Zahn, MD
What this data tells you about Dr. Zahn
Dr. Chester Zahn is a gastroenterology specialist in San Gabriel, CA, with 20 years of NPI registration. Based on federal Medicare data, Dr. Zahn performed 2,574 Medicare services across 1,729 unique beneficiaries.
Between the years covered by Open Payments, Dr. Zahn received a total of $1,253 from 14 pharmaceutical and/or device companies across 77 individual payments. These payments are legal, publicly disclosed under the federal Sunshine Act, and common in gastroenterology. Most payments are for meals and travel — low-value interactions common across virtually all practicing physicians. Patients may wish to discuss these relationships with their provider.
The Data Coverage level for Dr. Zahn is Very High — reflecting how much public federal data is available about this provider. Patients are encouraged to use this data as one of several factors when choosing a healthcare provider.
Medicare Practice Summary
Medicare Utilization ↗Top procedures by volume
Ranked by number of services performed for Medicare patients. Avg. submitted charge is what the provider billed; avg. Medicare payment is what CMS paid.
| Procedure | Volume | Avg. paid | Avg. submitted |
|---|---|---|---|
| Office visit, established patient (20-29 min) An office visit for an existing patient lasting between 20 and 29 minutes. The visit involves medical evaluation and management of the patient's condition. |
841 | $74 | $135 |
| Hospital follow-up visit, moderate complexity Follow-up hospital visit for an existing patient involving moderate medical decision making. The visit requires at least 35 minutes of time spent on the date of service. |
429 | $68 | $125 |
| Initial hospital admission, moderate complexity Initial hospital inpatient or observation care for a new patient involving moderate-level medical decision making, with at least 55 minutes total time on the date of the encounter. |
285 | $110 | $304 |
| Hospital follow-up visit, low complexity Follow-up hospital visit for an established patient with straightforward or low-level medical decision making. The visit requires at least 25 minutes of time spent on the day of service. |
224 | $42 | $105 |
| New patient office visit (45-59 min) An initial office visit for a new patient lasting between 45 and 59 minutes. This code covers the total time spent by the physician or qualified healthcare professional on the date of the encounter. |
201 | $136 | $300 |
| Upper GI endoscopy with biopsy A procedure to collect tissue samples from the esophagus, stomach, or upper small intestine using a flexible tube with a camera. The samples are examined to check for abnormalities. |
153 | $66 | $850 |
| Colonoscopy for colorectal cancer screening, high risk A colonoscopy performed to screen for colorectal cancer in individuals identified as being at high risk for the disease. |
63 | $179 | $950 |
| Destruction of large bowel polyp via endoscope Removal of a polyp or growth in the large intestine using a flexible tube with a camera. The procedure is performed through the endoscope to destroy the tissue. |
58 | $230 | $1,650 |
| Initial hospital admission, low complexity Initial hospital inpatient or observation care for a new patient involving straightforward or low-level medical decision making, with at least 40 minutes total time on the date of the encounter. |
53 | $71 | $195 |
| Endoscopic insertion of stomach tube A flexible endoscope is used to guide the placement of a tube into the stomach. |
52 | $161 | $1,000 |
| Hospital follow-up visit, high complexity Subsequent hospital inpatient or observation care for an existing patient involving high-level medical decision making, with at least 50 minutes total time on the date of the encounter. |
47 | $102 | $285 |
| Endoscopic control of upper GI bleeding A flexible endoscope is used to locate and stop bleeding in the esophagus, stomach, or upper small intestine. |
32 | $160 | $1,000 |
| Endoscopic removal of esophagus, stomach, or small bowel polyps This procedure uses an endoscope and a mechanical snare to remove polyps or growths from the esophagus, stomach, or upper small bowel. |
31 | $139 | $1,000 |
| Upper endoscopy (EGD) A diagnostic exam of the esophagus, stomach, and upper small bowel using a flexible endoscope. |
24 | $92 | $800 |
| Initial hospital admission, high complexity Initial hospital inpatient or observation care for a new patient involving high-level medical decision making, with at least 75 minutes total time on the date of the encounter. |
22 | $149 | $385 |
| Endoscopic control of bleeding in large intestine A flexible tube with a camera is inserted into the large intestine to locate and stop bleeding. |
16 | $112 | $1,700 |
| Endoscopic incision of pancreatic outlet A procedure where a flexible endoscope is used to make an incision in the pancreatic outlet. |
15 | $66 | $1,950 |
| Colonoscopy with biopsy A procedure to collect tissue samples from the large intestine using a flexible tube with a camera. The samples are examined to check for abnormalities or disease. |
15 | $77 | $1,150 |
| Repositioning of oral or nasal feeding tube in small bowel This procedure involves adjusting the position of a feeding tube that enters through the mouth or nose to ensure it is correctly placed within the small intestine. |
13 | $84 | $300 |
Industry Payment Transparency
Open Payments through 2024 ↗Payment profile
Industry payments classified by relationship type. Not all payments are equal — research and consulting reflect different relationships than speaking programs or meals.
Payment trend by year
Annual totals from pharmaceutical and medical device companies.
Payments by company (2024)
All-time payments by company (2018-2024) ›
Associated products mentioned in payments ›
Most payments (99%) are for meals and travel — low-value interactions that are common across virtually all practicing physicians.
Geographic Context
0.0 mi
Data Sources
| Provider Registry | ✓ NPPES | Weekly updates |
| Medicare Enrollment | ✓ PECOS | Monthly updates |
| Practice Data | ✓ Medicare Util. | Annual (CY lag) |
| Industry Payments | ✓ Open Payments | CY 2024 |
| Disciplinary History | — Not public | N/A |
This provider has data in 4 of 4 available federal datasets, with a Data Coverage level of Very High. This reflects how much public data is available about a provider. How we calculate this →
Summary
Dr. Zahn is a clinical cardiology specialist, with above-average Medicare volume (top 6% in CA), with low-engagement industry engagement, with 20 years of NPI registration.
This summary is auto-generated from federal data, describing data availability and patterns. Read our methodology →
Frequently Asked Questions
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All data on this page is sourced verbatim from public federal records published by the U.S. Centers for Medicare & Medicaid Services (CMS): NPPES ↗, Open Payments ↗, Medicare Provider Utilization ↗, and PECOS. Publication is mandated by the Physician Payments Sunshine Act (§6002 ACA, 42 U.S.C. §1320a-7h) and the Freedom of Information Act.
This page is not medical advice, an endorsement, a recommendation, or a quality rating. Data Coverage reflects data completeness — how much federal information exists for this provider — not clinical performance, patient outcomes, or quality of care. Always verify information directly with the provider and consult a licensed clinician before making medical decisions.
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