Doctor profile · Federal record
Dr. Chester Zahn, MD
Gastroenterology Physician (CMS: Gastroenterology) · San Gabriel, CA
- NPI 1639146442
- Accepts Medicare
- MIPS 30.8 / 100 · 2023
- 43 yrs in practice
- Male
- Solo practice
- No sanctions
Practice & contact
- Primary practice
-
1026 E Las Tunas Dr
San Gabriel, CA 917761633
(626) 287-7222
fax (626) 287-1991
Credentials & registration
- NPI registered
- March 2006 — 20 yrs on file
- Profile last updated
- March 20, 2020
- Year of graduation
- 1983 — 43 yrs since
- Specialty taxonomy
- 207RG0100X — NUCC code
- State license (1)
- California #G69510
- Medicaid
- CA #00G695100
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1639146442. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
2,713
Distinct HCPCS
10
Medicare allowed
$304,371
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99213 |
Established patient office or other outpatient visit, 20-29 minutes | 841 | 370 | $99 | |
99232 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 429 | 215 | $85 | |
99222 |
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes | 285 | 265 | $139 | |
99231 |
Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes | 224 | 108 | $53 | |
99204 |
New patient office or other outpatient visit, 45-59 minutes | 201 | 200 | $183 | |
43239 |
Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | 153 | 150 | $83 | |
99213 |
Established patient office or other outpatient visit, 20-29 minutes | 139 | 137 | $71 | |
G0105 |
Colorectal cancer screening; colonoscopy on individual at high risk | 63 | 63 | $179 | |
45388 |
Destruction of polyp or growth of large bowel using a flexible endoscope | 58 | 58 | $287 | |
99221 |
Initial hospital care with straightforward or low level of medical decision making, per day, if using time, at least 40 minutes | 53 | 52 | $88 |
In context: peer comparison
Among 1 peers in this city , average services per provider: 135. This provider delivers 20× the peer median.Open Payments
Industry payments received
All-time total
$296
Transactions
17
Manufacturers
5
| Payer (manufacturer) | Industry | Txns | Amount |
|---|---|---|---|
| Gilead Sciences, Inc. | 13 | $194.61 | |
| ABBVIE INC. | 1 | $30.37 | |
| Janssen Biotech, Inc. | 1 | $24.93 | |
| ALBIREO PHARMA, INC. | 1 | $23.33 | |
| Phathom Pharmaceuticals, Inc. | 1 | $22.82 |
By nature of payment
Medicare Part D · 2023
Top prescriptions
Total claims
2,873
Patients
992
Total drug cost
$230,199
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Bethanechol Chloride | Generic | 1,251 | 393 | $122,744 |
| Omeprazole | Generic | 546 | 178 | $9,721 |
| Gavilyte-G (Peg3350/Sod Sulf,bicarb,cl/Kcl) | Brand | 223 | 218 | $3,999 |
| Isosorbide Mononitrate Er (Isosorbide Mononitrate) | Brand | 183 | 58 | $6,546 |
| Entecavir | Generic | 112 | 16 | $62,061 |
| Rosuvastatin Calcium | Generic | 109 | 31 | $4,495 |
| Ursodiol | Generic | 96 | 21 | $11,325 |
| Clopidogrel (Clopidogrel Bisulfate) | Brand | 74 | 29 | $1,616 |
| Pantoprazole Sodium | Generic | 57 | 16 | $858 |
| Metformin Hcl | Generic | 43 | 0 | $353 |
Hospital affiliations
Frequently asked questions
What is Dr. Chester Zahn's medical specialty?
Dr. Chester Zahn practices Gastroenterology Physician in San Gabriel, CA.
Where does Dr. Chester Zahn practice?
Dr. Chester Zahn practices at 1026 E Las Tunas Dr, San Gabriel, CA 917761633. Office phone: 6262877222.
What is Dr. Chester Zahn's NPI?
Dr. Chester Zahn's National Provider Identifier (NPI) is 1639146442, issued by NPPES.
Does Dr. Chester Zahn accept Medicare assignment?
Yes. Dr. Chester Zahn accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Chester Zahn commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99213); Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Initial hospital care with straightforward or low-level medical decision making (HCPCS 99222). Source: CMS Medicare Physician & Other Practitioners file.