Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Jason Haas, DO

Individual provider Gastroenterology Physician · NPI 1790948008

Jason Haas, DO practises Gastroenterology in Chesterfield, Missouri. Graduated from At Still University of Health Sciences, College of Osteo Med, Kirksville in 2008, 18 years ago. Practices with Gateway Gastroenterology Inc, a 25-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in Missouri.

Years since qualifying
18
Trained at
At Still University of Health Sciences, College of Osteo Med, Kirksville
Licensed in
MO
In the registry since
2008
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

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Practice location Address checks out

17298 N Outer 40 Rd Ste 406
Chesterfield, MO 63005-1455
Phone: (314) 529-4900
Fax: (314) 434-2679
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 1008 Greystone Manor Pkwy, Chesterfield, MO 63005-4941 — (608) 780-1566

Specialties & licences

Gastroenterology Physician (primary) Taxonomy 207RG0100X · Licence 2014006550 (MO)

Record details

NPI number1790948008
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorNo
NPI enumeratedJuly 7, 2008
Last updated in NPPESAugust 6, 2026
Certification dateAugust 6, 2026

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyGASTROENTEROLOGY
Medical schoolAT STILL UNIVERSITY OF HEALTH SCIENCES, COLLEGE OF OSTEO MED, KIRKSVILLE
Graduated 2008 (18 years in practice)
Group practice Gateway Gastroenterology Inc — 25 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Colonoscopy 94 times · 78th percentile
Upper gastrointestinal (GI) endoscopy for acid reflux 107 times · 78th percentile

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients446
Services billed 2,540 a service is one billed item, such as a visit, a test or a procedure
Average patient age74

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Gateway Gastroenterology Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 25 clinicians in the practice; 12 are shown here.

Other providers in Chesterfield