Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. Margaret Janina Slowik, OD

Individual provider Optometrist · NPI 1124222591

Dr. Margaret Janina Slowik, OD is registered under Optometry in LA Grange, Illinois. Graduated from Illinois College of Optometry at Chicago in 1994, 32 years ago. Practices with Rosin Optical Co Inc, a 51-clinician group and accepts Medicare assignment. Licensed in Illinois.

Years since qualifying
32
Trained at
Illinois College of Optometry at Chicago
Licensed in
IL
In the registry since
2007
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

100 W Calendar Ave
LA Grange, IL 60525-2325
Phone: (708) 354-0500
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Optometrist (primary) Taxonomy 152W00000X · Licence 046008760 (IL)

Record details

NPI number1124222591
Entity typeIndividual (Type 1)
GenderFemale
Credentials OD
Sole proprietorNo
NPI enumeratedJune 12, 2007
Last updated in NPPESJanuary 25, 2024
Certification dateJanuary 25, 2024

Medicare enrollment

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

Medicare specialtyOPTOMETRY
Medical schoolILLINOIS COLLEGE OF OPTOMETRY AT CHICAGO
Graduated 1994 (32 years in practice)
Group practice Rosin Optical Co Inc — 51 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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 patients62
Services billed 68 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 $599 8 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.

Colleagues at Rosin Optical Co Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 51 clinicians in the practice; 12 are shown here.

Other providers in LA Grange