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

Matthew Krewer, OD

Individual provider Optometrist · NPI 1003269721

Matthew Krewer, OD is registered under Optometry in Waterloo, Iowa. Qualified in 2016, 10 years ago. Practices with Cedar Valley Medical Specialists PC, a 76-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in Iowa and Washington.

Years since qualifying
10
Licensed in
IA, WA
In the registry since
2016
Specialties on file
2
What do these letters mean?
OD — Doctor of Optometry
An optometrist: examines eyes, prescribes glasses and contacts, and treats many eye conditions.

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Practice location Address checks out

909 E San Marnan Dr
Waterloo, IA 50702-5611
Phone: (319) 233-2020
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 1409 W 1st St, Cedar Falls, IA 50613-2115 — (319) 268-2020

Specialties & licences

Optometrist (primary) Taxonomy 152W00000X · Licence 097765 (IA)
Optometrist Taxonomy 152W00000X · Licence OD60679692 (WA)

Record details

NPI number1003269721
Entity typeIndividual (Type 1)
GenderMale
Credentials OD
Sole proprietorNo
NPI enumeratedJuly 18, 2016
Last updated in NPPESJanuary 31, 2023
Certification dateJanuary 31, 2023

Medicare enrollment

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

Medicare specialtyOPTOMETRY
Medical schoolOTHER
Graduated 2016 (10 years in practice)
Group practice Cedar Valley Medical Specialists Pc — 76 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations4 on file with Medicare

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 patients286
Services billed 381 a service is one billed item, such as a visit, a test or a procedure
Average patient age73

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 $112 5 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.

  • Allen Hospital Hospital · Waterloo, IA · listed as Allen Memorial Hospital

Colleagues at Cedar Valley Medical Specialists PC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 76 clinicians in the practice; 12 are shown here.

Other providers in Waterloo