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- 1026 E Las Tunas Dr, San Gabriel, CA 91776
About Dr. Zahn
Chester D. Zahn, MD practices gastroenterology in San Gabriel, CA. Chester is a 1983 graduate of Stanford University School of Medicine. According to Medicare claims data, Chester cared for 2,069 Medicare patients across 2,761 services. The services billed most often include established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more, initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes, and subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes. The provider's National Provider Identifier (NPI) is 1639146442.
Factual summary compiled by Guide.md from public records; not written by this provider.
Education & Training
Specialty
Credentials & Licensing
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (626) 287-7222
- Email not available
Is this your home address or personal number? Hide it
Practice Locations
1026 E LAS TUNAS DR
San Gabriel, CA 91776
Conditions Commonly Evaluated or Treated
Within Gastroenterology generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Conditions
Chronic conditions
Liver health
Specialized and cancer
- Short bowel syndrome
Wound care
- Feeding Tube Site Irritation
Most searched conditions
- Acid reflux
- Celiac disease
- Crohn's disease
- Hemorrhoids
- IBS
- Swallowing difficulties
- Ulcerative colitis
Biliary and pancreas
- Acute pancreatitis
- Gallstones
- Pancreatic cysts
- Primary sclerosing cholangitis
Colon and anorectal
- Anal fissure
- Colon cancer
- Colon polyps
- Lower gastrointestinal bleeding
Esophagus and swallowing
- Barrett's esophagus
- Eosinophilic esophagitis
- Esophageal stricture
- Esophagitis
Functional bowel and motility
- Chronic diarrhea
- Fecal incontinence
- Small intestinal bacterial overgrowth
Liver
- Ascites
- Autoimmune hepatitis
- Cirrhosis
- Fatty liver disease
- Hemochromatosis
- Hepatitis B
- Hepatitis C
- Portal hypertension
Stomach and duodenum
- Functional dyspepsia
- Gastritis
- Gastroparesis
- H. pylori infection
- Peptic ulcer disease
Bowel & Colon
Digestive Symptoms
Gallbladder & Bile Ducts
- Blocked Bile Duct
Procedures & services
Advanced endoscopy
- EUS-guided biopsy
Biliary and pancreatic endoscopy
- Biliary sphincterotomy
- Endoscopic bile duct stone removal
Capsule and physiology testing
- Ambulatory reflux monitoring
- Capsule endoscopy
- Hydrogen and methane breath testing
- Anorectal manometry
- Esophageal manometry
Chronic illness
- Feeding tube care and troubleshooting
Clinical Nutrition
Diagnostic Testing
- 24-Hour Acid Reflux Test
- H. Pylori Breath Test
- SIBO Breath Test
- EUS-Guided Fine Needle Biopsy
Digestive
- Bowel Retraining Program
General surgery
- Hemorrhoid banding and treatment
Infection & Microbiology Tests
Liver procedures
- Paracentesis
- Esophageal variceal banding
- Liver elastography
Lower endoscopy
- Colon polyp removal
- Diagnostic colonoscopy
- Endoscopic control of gastrointestinal bleeding
- Flexible sigmoidoscopy
Nursing care
- G-Tube Button Replacement
Nutrition & Digestion
- Feeding tube placement
Upper endoscopy
- Endoscopic mucosal resection
- Esophageal biopsy
- Esophageal dilation
- Stomach biopsy
- Endoscopic submucosal dissection
Most searched procedures
- Colonoscopy
- Endoscopy
- Gallbladder removal
- Hernia repair
- Liver biopsy
Treatments
- Stool Transplant
Procedures Most Often Billed to Medicare
2,761 services · 2,069 patients · 22 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43239 |
164 | More than most peers in Gastroenterology |
| Insertion of stomach tube using a flexible endoscope | Procedure | 43246 |
76 | More than most peers in Gastroenterology |
| Destruction of polyp or growth of large bowel using a flexible endoscope | Procedure | 45388 |
52 | More often than most peers in Gastroenterology |
| Control of bleeding of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43255 |
43 | More than most peers in Gastroenterology |
| Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43235 |
31 | More often than most peers in Gastroenterology |
| Removal of polyps or growths of esophagus, stomach, and/or upper small bowel using an endoscope with mechanical snare | Procedure | 43251 |
30 | More often than most peers in Gastroenterology |
| Replacement of stomach stoma tube | Procedure | 43762 |
26 | As often as other peers in Gastroenterology |
| Incision of pancreatic outlet using a flexible endoscope | Procedure | 43262 |
21 | More often than most peers in Gastroenterology |
| Balloon dilation of pancreatic or bile duct or sphincter using a flexible endoscope | Procedure | 43277 |
20 | More often than most peers in Gastroenterology |
| Repositioning of oral or nasal feeding tube in small bowel | Procedure | 43761 |
19 | Too few peers to compare |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Also at this address 1
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
Other gastroenterologists in San Gabriel 2
Same specialty, same city.
Trained at Stanford University School of Medicine 8
Other providers in the same specialty who trained at the same institution.
More connections — 16 related providers in 2 groups
Class of 1983 at Stanford University School of Medicine 8
Providers who graduated from the same medical school in the same year.
Also performs Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope 8
Providers in CA who bill this service to Medicare most often.
Common questions
What does Dr. Zahn specialize in?
Dr. Zahn is a gastroenterologist in San Gabriel, CA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Gastroenterology”.
NPI registry
Where is Dr. Zahn located?
Dr. Zahn is listed at 1026 E Las Tunas Dr, San Gabriel, CA 91776. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
What is Dr. Zahn's phone number?
The number on file is (626) 287-7222. Contact the office directly to confirm availability and scheduling.
NPI registry
What is Dr. Zahn's NPI number?
Dr. Zahn's National Provider Identifier is 1639146442. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Where did Dr. Zahn go to medical school?
Dr. Zahn attended Stanford University School of Medicine, graduating in 1983. This comes from the CMS National Downloadable File.
CMS public data
How long has Dr. Zahn been practicing?
Dr. Zahn has 43 years experience. Calculated from a graduation year of 1983, reported in the CMS National Downloadable File.
CMS public data
What does Dr. Zahn do most often?
According to Medicare billing data, Dr. Zahn performs procedures including biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope, insertion of stomach tube using a flexible endoscope and destruction of polyp or growth of large bowel using a flexible endoscope, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Has Dr. Zahn confirmed this information?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Zahn. If this is you, claiming it is free.
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