Louis Chang, M.D., PH.D.
NPI 1538295720 · Ophthalmology Physician · Los Angeles, CA
Enrolled with Medicare as Practitioner - Ophthalmology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Louis Chang, M.D., PH.D. is a Ophthalmology Physician provider in Los Angeles, CA (NPI 1538295720).
Provider details
- NPI number
- 1538295720
- Entity type
- Individual
- Primary specialty
- Ophthalmology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D., PH.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A91494 (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
5,709 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) |
|---|---|---|
| Imaging of Retina92134 | 2,238 | $54 |
| Injection of Drug Into Eye67028 | 1,315 | $156 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 991 | $116 |
| Established Patient Complete Exam of Visual System92014 | 316 | $168 |
| Established Patient Problem Focused Exam of Visual System92012 | 299 | $118 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 156 | $163 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Prednisolone Acetate | 63 | 28 |
| Ketorolac Tromethamine | 34 | 12 |
| Diclofenac Sodium | 31 | — |
| Neomycin/Polymyxin B/Dexamethabrand: Neomycin-Polymyxin-Dexameth | 25 | 17 |
| Brimonidine Tartrate | 16 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$89 across 3 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
- 2007-02-24
- Last updated
- 2007-07-08
Frequently asked questions
- What is Louis Chang's NPI number?
- Louis Chang's National Provider Identifier (NPI) is 1538295720, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Louis Chang's specialty?
- Louis Chang is listed in the NPPES registry with a primary specialty of Ophthalmology Physician (Allopathic & Osteopathic Physicians).
- Where is Louis Chang located?
- Louis Chang's practice location on file with NPPES is 100 Stein Plz, Los Angeles, CA 90095-7065.
- What is Louis Chang's phone number?
- The practice phone number listed in the NPPES registry for Louis Chang is (310) 473-8878.
- Does Louis Chang accept Medicare?
- Louis Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Louis Chang's NPI active?
- Yes — Louis Chang's NPI (1538295720) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.