Joseph Chen, M.D.
NPI 1639496953 · Ophthalmology Physician · Westlake Village, CA
Enrolled with Medicare as Practitioner - Ophthalmology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Joseph Chen, M.D. is a Ophthalmology Physician provider in Westlake Village, CA (NPI 1639496953).
Provider details
- NPI number
- 1639496953
- Entity type
- Individual
- Primary specialty
- Ophthalmology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- BP20036802 (TX)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
16 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
3,540 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 Problem Focused Exam of Visual System92012 | 651 | $99 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 454 | $136 |
| Exam of Visual Field With Extended Testing92083 | 393 | $58 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 389 | $97 |
| Imaging of Optic Nerve92133 | 288 | $40 |
| Measurement of Corneal Curvature and Depth of Eye92136 | 193 | $31 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 32 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Latanoprost | 676 | 207 |
| Dorzolamide Hcl/Timolol Maleatbrand: Dorzolamide-Timolol | 397 | 112 |
| Prednisolone Acetate | 359 | 192 |
| Timolol Maleate | 331 | 124 |
| Brimonidine Tartrate | 224 | 75 |
| Bimatoprostbrand: Lumigan | 219 | 69 |
| Moxifloxacin Hclbrand: Moxifloxacin | 204 | 124 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$2,471 across 63 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
- 2010-04-26
- Last updated
- 2023-07-10
- Certified
- 2023-07-10
Frequently asked questions
- What is Joseph Chen's NPI number?
- Joseph Chen's National Provider Identifier (NPI) is 1639496953, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Joseph Chen's specialty?
- Joseph Chen is listed in the NPPES registry with a primary specialty of Ophthalmology Physician (Allopathic & Osteopathic Physicians).
- Where is Joseph Chen located?
- Joseph Chen's practice location on file with NPPES is 4353 Park Terrace Dr Ste 150, Westlake Village, CA 91361-4639.
- What is Joseph Chen's phone number?
- The practice phone number listed in the NPPES registry for Joseph Chen is (805) 987-5300.
- Does Joseph Chen accept Medicare?
- Joseph Chen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Joseph Chen's NPI active?
- Yes — Joseph Chen's NPI (1639496953) is active in the NPPES registry as of the last update on 2023-07-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.