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

Dr. Larry Johnston, DO

Individual provider Gastroenterology Physician · NPI 1386036333

Dr. Larry Johnston, DO practises Gastroenterology in Ames, Iowa. Graduated from Oklahoma State University College of Osteopathic Medicine in 2015, 11 years ago. Practices with McFarland Clinic PC, a 353-clinician group and accepts Medicare assignment. Licensed in Iowa and Oklahoma.

Years since qualifying
11
Trained at
Oklahoma State University College of Osteopathic Medicine
Licensed in
IA, OK
In the registry since
2015
Specialties on file
2
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

1215 Duff Ave
Ames, IA 50010-5469
Phone: (515) 239-4450
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Gastroenterology Physician (primary) Taxonomy 207RG0100X · Licence 05983 (IA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 6004 (OK)

Record details

NPI number1386036333
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorYes
NPI enumeratedFebruary 28, 2015
Last updated in NPPESAugust 2, 2022
Certification dateAugust 2, 2022

Medicare enrollment

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

Medicare specialtyGASTROENTEROLOGY
Medical schoolOKLAHOMA STATE UNIVERSITY COLLEGE OF OSTEOPATHIC MEDICINE
Graduated 2015 (11 years in practice)
Group practice McFarland Clinic Pc — 353 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 234 times · 95th percentile
Upper gastrointestinal (GI) endoscopy for acid reflux 290 times · 95th 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 patients418
Services billed 1,247 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.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $437 19 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

Colleagues at McFarland Clinic PC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 353 clinicians in the practice; 12 are shown here.

Other providers in Ames