1. Home
  2. Directory
  3. California
  4. San Mateo
  5. Optometrist
  6. NPI Profile

WILLIAM Y. TO, O.D., INC
NPI 1700448925
Optometrist in San Mateo, CA

Active since July 08, 2019
194 HILLSDALE SHOPPING CENTER, SAN MATEO, CA 94403(650) 341-8080(650) 341-8565 Get Directions Write a Review

NPPES record last updated: September 3, 2025. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Sep 3, 2025, Mar 20, 2025, Jul 2, 2024 and 6 more (9 updates tracked since 2019).

About William Y. To, O.d., Inc NPPES

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

WILLIAM Y. TO, O.D., INC (NPI 1700448925), doing business as Lifetime Eyecare By Optical Illusions, is a healthcare organization registered as an optometrist in San Mateo, California and active in the NPI registry since July 2019. The organization maintains 3 additional practice locations and lists Katalina Ashe Rowland Yandell, Chief Operations Officer, as its authorized official.

NPPES Registry Identity

NPI1700448925
Entity TypeOrganization
Primary Taxonomy152W00000X
Legal Business NameWILLIAM Y. TO, O.D., INC
Location Address194 HILLSDALE SHOPPING CENTERSan Mateo, CA 94403-3409
Mailing Address1750 Lundy Ave Unit 612899San Jose, CA 95161-7117 · (408) 960-4498
Phone(650) 341-8080
Fax(650) 341-8565
Organization SubpartNo
Authorized OfficialKatalina Ashe Rowland YandellChief Operations Officer · (425) 445-6120
Enumeration DateJuly 8, 2019
Last NPPES UpdateSeptember 3, 20259 updates tracked since enumeration
NPPES CertifiedSeptember 3, 2025
✔ NPI 1700448925 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyOptometristEye and Vision Services Providers
Taxonomy Code152W00000X
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.
194 HILLSDALE SHOPPING CENTER, San Mateo, CA 94403
Open in Google Maps ↗

Other Names 5

Doing Business AsLifetime Eyecare By Optical Illusions
Doing Business AsOptical Illusions Of San Jose: An Optometric Practice
Doing Business AsOptical Illusions Of San Mateo: An Optometric Practice
Doing Business AsOptical Illusions Of San Ramon: An Optometric Practice
Doing Business AsOptical Illusions: An Optometric Practice

Secondary Practice Locations 3

Location 19309 Glacier Hwy Ste A103Juneau, AK 99801-9300 · Phone (907) 789-3175 · Fax (844) 903-4362
Location 26000 Bollinger Canyon Rd Ste 1104San Ramon, CA 94583-2305 · Phone (925) 725-1745 · Fax (925) 725-7922
Location 3377 Santana Row Ste 1115San Jose, CA 95128-2058 · Phone (408) 502-5020 · Fax (408) 389-8261

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

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 Montana, Blue Cross and Blue Shield of Oklahoma and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

William Y. To, O.d., Inc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

8

Medicare enrollment records show 8 clinicians reassign Medicare billing to William Y. To, O.D., Inc, which bills Medicare for the services they deliver. Of these, 3 practice at this address. They are listed nearest first.

Clinicians, nearest first (8)

Paris Montgomery, OD
Optometry
NPI 1134737794
194 HILLSDALE SHOPPING CENTER
San Mateo, CA 94403
(650) 341-8080
✔ PECOSSame address
Erica Ngo, O.D.
Optometry
NPI 1124575790
194 HILLSDALE SHOPPING CENTER
San Mateo, CA 94403
(650) 341-8080
✔ PECOS✔ Accepts MedicareSame address
William To, OD
Optometry
NPI 1952756678
194 HILLSDALE SHOPPING CENTER
San Mateo, CA 94403
(650) 341-8080
✔ PECOS✔ Accepts MedicareSame address
Katalina Yandell, OD
Optometry
NPI 1871071589
377 SANTANA ROW STE 1115
San Jose, CA 95128
(408) 502-5020
✔ PECOS✔ Accepts Medicare24 mi
Tina Shafa, OD
Optometry
NPI 1164370052
6000 BOLLINGER CANYON RD STE 1104
San Ramon, CA 94583
(925) 725-1745
✔ PECOS25 mi
Lizeth Gonzalez, OD
Optometry
NPI 1598376113
4060 FAIRMOUNT AVE
San Diego, CA 92105
(619) 280-4213
✔ PECOS✔ Accepts Medicare442 mi
Atean Asslani, OD
Optometry
NPI 1568352276
2743 HIGHLAND AVE
National City, CA 91950
(844) 200-2426
✔ PECOS✔ Accepts Medicare447 mi
Elizabeth Hunt, OD
Optometry
NPI 1942589783
3100 CHANNEL DR
Juneau, AK 99801
(907) 463-4040
✔ PECOS✔ Accepts Medicare1,538 mi

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

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 William Y. To, O.D., Inc's NPI number?

The NPI number for William Y. To, O.D., Inc is 1700448925. It was assigned to this organization in the NPPES registry on July 8, 2019. The provider is doing business as Lifetime Eyecare by Optical Illusions, Optical Illusions of San Jose: An Optometric Practice, Optical Illusions of San Mateo: An Optometric Practice and Optical Illusions of San Ramon: An Optometric Practice. Additional names are listed in the Other Names section above.

Where is William Y. To, O.D., Inc located?

William Y. To, O.D., Inc is located at 194 Hillsdale Shopping Center, San Mateo, CA 94403. The listed phone number is (650) 341-8080.

What is William Y. To, O.D., Inc's specialty?

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

Is William Y. To, O.D., Inc enrolled in Medicare?

Yes. William Y. To, O.D., Inc is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through William Y. To, O.D., Inc?

According to the CMS Revalidation Reassignment List (October 2026 release), 8 clinicians, all in Optometry, reassign their Medicare billing to William Y. To, O.D., Inc. A 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 the clinician's services. Of these, 3 practice at this address. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

What insurance does William Y. To, O.D., Inc accept?

Health plans from Anthem Blue Cross and Blue Shield, Blue Cross and Blue Shield of Montana, Blue Cross and Blue Shield of Oklahoma, Blue Cross and Blue Shield of Texas and BlueCross BlueShield of Tennessee and 1 other insurer list William Y. To, O.D., Inc 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 William Y. To, O.D., Inc was last updated on September 3, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 months 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.