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DR. JOHN ILSUN RYU O.D.
NPI 1609946847
Optometrist in Simi Valley, CA

Active since November 08, 2006PECOS Enrolled
690 E LOS ANGELES AVE, SUITE A, SIMI VALLEY, CA 93065(626) 376-3513(905) 250-1001 Get Directions Write a Review

NPPES record last updated: July 15, 2024. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Dr. John Ilsun Ryu O.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. JOHN ILSUN RYU O.D. (NPI 1609946847) is an individual optometrist in Simi Valley, California, licensed in California (11209T) and active in the NPI registry since November 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1609946847
Entity TypeIndividualMale
Primary Taxonomy152W00000X
Provider Legal NameDR. JOHN ILSUN RYUCredential: O.D.
Location Address690 E LOS ANGELES AVE, SUITE ASimi Valley, CA 93065-1857
Mailing Address1194 Knottingham StSimi Valley, CA 93065-5167 · (626) 376-3513 · Fax (805) 250-1001
Phone(626) 376-3513
Fax(905) 250-1001
Sole ProprietorYes
Enumeration DateNovember 8, 2006
Last NPPES UpdateJuly 15, 2024
NPPES CertifiedJuly 15, 2024
✔ NPI 1609946847 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyOptometristEye and Vision Services Providers
Taxonomy Code152W00000X
License✔ Licensed in CA · 11209T
Definition
Doctors of optometry (ODs) are the primary health care professionals for the eye. Optometrists examine, diagnose, treat, and manage diseases, injuries, and disorders of the visual system, the eye, and associated structures as well as identify related systemic conditions affecting the eye. An optometrist has completed pre-professional undergraduate education in a college or university and four years of professional education at a college of optometry, leading to the doctor of optometry (O.D.) degree. Some optometrists complete an optional residency in a specific area of practice. Optometrists are eye health care professionals state-licensed to diagnose and treat diseases and disorders of the eye and visual system.
690 E LOS ANGELES AVE, Simi Valley, CA 93065
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Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield, Blue Cross and Blue Shield of Louisiana, Blue Cross and Blue Shield of Montana and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. John Ilsun Ryu O.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency– Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignment

Medicare enrollment records show John Ryu reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Summit Optometric Eyecare
Same address
Optometrist
690 E LOS ANGELES AVE, SUITE A
Simi Valley, CA 93065
  • Reassigned Medicare billing, California enrollment
NPI 1053757039 (626) 376-3513

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 93065 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$140.72 typical visit price
range $62.32 – $185.36
Typical copayment $35.18 (range $15.58 – $46.34)
Most-billed visit code 99204
Established Patient
$77.11 typical visit price
range $20.68 – $151.85
Typical copayment $19.27 (range $5.17 – $37.96)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

SUMMIT OPTOMETRIC EYECARE
Optometrist
690 E LOS ANGELES AVE, SUITE A
SIMI VALLEY, CA 93065
Ventura County (626) 376-3513

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is John Ryu's NPI number?

The NPI number for John Ryu is 1609946847. It was assigned to this individual provider in the NPPES registry on November 8, 2006.

Where is John Ryu located?

John Ryu practices at 690 E Los Angeles Ave Suite A, Simi Valley, CA 93065. The listed phone number is (626) 376-3513.

What is John Ryu's specialty?

The primary specialty registered for this NPI is Optometrist with taxonomy code 152W00000X.

Is John Ryu enrolled in Medicare?

Yes. John Ryu is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for John Ryu's services?

According to the CMS Revalidation Reassignment List (October 2026 release), John Ryu reassigns Medicare benefits to Summit Optometric Eyecare (Simi Valley, CA). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for John Ryu's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does John Ryu accept?

Health plans from Anthem Blue Cross and Blue Shield, Blue Cross and Blue Shield of Louisiana, Blue Cross and Blue Shield of Montana, Blue Cross and Blue Shield of Oklahoma and Blue Cross and Blue Shield of Texas and 1 other insurer list John Ryu as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

When was this NPI record last updated?

The NPPES record for John Ryu was last updated on July 15, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.