Physician Profile
Daniel Rengstorff, M.D.
Unclaimed ProfileAbout Dr. Rengstorff
Daniel Rengstorff, M.D. practices gastroenterology in San Mateo, CA. Daniel is a 1998 graduate of Georgetown University School of Medicine. According to Medicare claims data, Daniel cared for 475 Medicare patients across 520 services. The services billed most often include established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more, established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more, and biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope.
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it — free, and no identity document with a practice or institutional email.
Education & Training
Specialty
Credentials & Licensing
License numbers are what the provider reported to NPPES when the NPI was issued or updated. NPPES does not verify licensure; confirm current standing with the state licensing board.
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
- (650) 341-9131
- Email not available
Practice Locations
218 DE ANZA BLVD
San Mateo, CA 94402
2900 Whipple Ave Ste 245
Redwood City, CA 94062
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
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
- Diverticulitis
Digestive Symptoms
- Constipation
Gallbladder & Bile Ducts
- Blocked Bile Duct
Procedures & services
Most searched procedures
- Colonoscopy
- Endoscopy
- Gallbladder removal
- Hernia repair
- Liver biopsy
Lower endoscopy
- Colon polyp removal
- Endoscopic control of gastrointestinal bleeding
- Flexible sigmoidoscopy
Upper endoscopy
- Endoscopic submucosal dissection
- Esophageal dilation
Capsule and physiology testing
- Anorectal manometry
- Capsule endoscopy
- Esophageal manometry
Diagnostic Testing
- 24-Hour Acid Reflux Test
- EUS-Guided Fine Needle Biopsy
- H. Pylori Breath Test
- SIBO Breath Test
Liver procedures
- Esophageal variceal banding
- Liver elastography
- Paracentesis
Treatments
- Stool Transplant
Procedures Most Often Billed to Medicare
520 services · 475 patients · 8 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | Procedure | 43239 |
73 | As often as other peers in Gastroenterology |
| Biopsy of large bowel using a flexible endoscope | Procedure | 45380 |
57 | As often as other peers in Gastroenterology |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | Procedure | 45385 |
29 | Less often than most peers in Gastroenterology |
| Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | Office visit | 99214 |
118 | More often than most peers in Gastroenterology |
| Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more | Office visit | 99213 |
82 | More often than most peers in Gastroenterology |
| New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more | Office visit | 99203 |
57 | More often than most peers in Gastroenterology |
| New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more | Office visit | 99204 |
55 | More often than most peers in Gastroenterology |
| Colorectal cancer screening; colonoscopy on individual not meeting criteria for high risk | Billing code | G0121 |
49 | More than most peers in Gastroenterology |
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 4
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 Mateo 3
Same specialty, same city.
Trained at Georgetown 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 1998 at Georgetown 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 Daniel Rengstorff specialize in?
Daniel Rengstorff is a gastroenterologist in San Mateo, CA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Gastroenterology”.
NPI registry
Where is Daniel Rengstorff located?
Daniel Rengstorff is listed at 218 de Anza Blvd, San Mateo, CA 94402. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
What is Daniel Rengstorff's phone number?
The number on file is (650) 341-9131. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is Daniel Rengstorff's NPI number?
Daniel Rengstorff's National Provider Identifier is 1033295662. 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 Daniel Rengstorff train?
Daniel Rengstorff attended Georgetown University School of Medicine, graduating in 1998. This comes from the CMS National Downloadable File.
CMS public data
How long has Daniel Rengstorff been practicing?
Daniel Rengstorff has 28 years experience. Calculated from a graduation year of 1998, reported in the CMS National Downloadable File.
CMS public data
What does Daniel Rengstorff do most often?
According to Medicare billing data, Daniel Rengstorff performs procedures including biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope, biopsy of large bowel using a flexible endoscope and removal of polyps or growths of large bowel using an endoscope with mechanical snare, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Has Daniel Rengstorff confirmed this information?
Not yet. This profile is built from public federal data and has not been confirmed by Daniel Rengstorff. If this is you, claiming it is free.
Guide.md
Provider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.