John Chan, M.D.
NPI 1609928837 · Ophthalmology Physician · Union City, CA
Enrolled with Medicare as Practitioner - Ophthalmology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Chan, M.D. is a Ophthalmology Physician provider in Union City, CA (NPI 1609928837).
Provider details
- NPI number
- 1609928837
- Entity type
- Individual
- Primary specialty
- Ophthalmology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A70464 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
12 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. 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 .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 12 | $103 |
Typical Medicare-allowed amounts for these services range $103–$103 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 13 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Latanoprost | 486 | 200 |
| Timolol Maleate | 267 | 95 |
| Dorzolamide Hcl/Timolol Maleatbrand: Dorzolamide-Timolol | 173 | 60 |
| Brimonidine Tartrate | 123 | 57 |
| Cyclosporine | 62 | 16 |
| Prednisolone Acetate | 47 | 31 |
| Neomycin/Polymyxin B/Dexamethabrand: Neomycin-Polymyxin-Dexameth | 44 | 29 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$43 across 1 record (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
- 2007-01-17
- Last updated
- 2021-12-06
Frequently asked questions
- What is John Chan's NPI number?
- John Chan's National Provider Identifier (NPI) is 1609928837, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Chan's specialty?
- John Chan is listed in the NPPES registry with a primary specialty of Ophthalmology Physician (Allopathic & Osteopathic Physicians).
- Where is John Chan located?
- John Chan's practice location on file with NPPES is 3553 Whipple Rd, Union City, CA 94587-1507.
- What is John Chan's phone number?
- The practice phone number listed in the NPPES registry for John Chan is (510) 454-1000.
- Does John Chan accept Medicare?
- John Chan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Chan's NPI active?
- Yes — John Chan's NPI (1609928837) is active in the NPPES registry as of the last update on 2021-12-06.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.