John Gialousakis, O.D.
NPI 1184038606 · Optometrist · Downers Grove, IL
Enrolled with Medicare as Practitioner - Optometry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Gialousakis, O.D. is a Optometrist provider in Downers Grove, IL (NPI 1184038606).
Provider details
- NPI number
- 1184038606
- Entity type
- Individual
- Primary specialty
- OptometristEye and Vision Services Providers
- Credential
- O.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 046011186 (IL)
Specialties & taxonomies
Eye and Vision Services Providers
Eye and Vision Services Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
12 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$300 across 6 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2014-06-12
- Last updated
- 2019-06-05
Frequently asked questions
- What is John Gialousakis's NPI number?
- John Gialousakis's National Provider Identifier (NPI) is 1184038606, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Gialousakis's specialty?
- John Gialousakis is listed in the NPPES registry with a primary specialty of Optometrist (Eye and Vision Services Providers).
- Where is John Gialousakis located?
- John Gialousakis's practice location on file with NPPES is 3450 Lacey Rd, Downers Grove, IL 60515-5430.
- What is John Gialousakis's phone number?
- The practice phone number listed in the NPPES registry for John Gialousakis is (630) 743-4500.
- Does John Gialousakis accept Medicare?
- John Gialousakis is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Gialousakis's NPI active?
- Yes — John Gialousakis's NPI (1184038606) is active in the NPPES registry as of the last update on 2019-06-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.