Dr. Tom Chang, MD
What this data tells you about Dr. Chang
Dr. Tom Chang is an ophthalmology specialist in Pasadena, CA, with 20 years of NPI registration. Based on federal Medicare data, Dr. Chang performed 14,043 Medicare services across 2,521 unique beneficiaries.
Between the years covered by Open Payments, Dr. Chang received a total of $803 from 7 pharmaceutical and/or device companies across 11 individual payments. These payments are legal, publicly disclosed under the federal Sunshine Act, and common in ophthalmology. Most payments are for meals and travel — low-value interactions common across virtually all practicing physicians. Patients may wish to discuss these relationships with their provider.
The Data Coverage level for Dr. Chang is Very High — reflecting how much public federal data is available about this provider. Patients are encouraged to use this data as one of several factors when choosing a healthcare provider.
Medicare Practice Summary
Medicare Utilization ↗Top procedures by volume
Ranked by number of services performed for Medicare patients. Avg. submitted charge is what the provider billed; avg. Medicare payment is what CMS paid.
| Procedure | Volume | Avg. paid | Avg. submitted |
|---|---|---|---|
| Injection, ranibizumab, 0.1 mg | 3,990 | $186 | $500 |
| Retinal imaging (OCT scan) This procedure involves imaging the retina to visualize its structure. It is used to examine the back of the eye. |
2,659 | $32 | $88 |
| Ranibizumab-eqrn injection, 0.1 mg An injection of the biosimilar medication ranibizumab-eqrn (Cimerli) in a 0.1 mg dose. |
2,037 | $216 | $500 |
| Eye injection for retinal disease A procedure involving the administration of medication directly into the eye. |
1,889 | $92 | $552 |
| Pegcetacoplan intravitreal injection, 1 mg An injection of pegcetacoplan administered into the vitreous humor of the eye. The dose specified is 1 milligram. |
1,096 | $120 | $398 |
| Eye exam, established patient, focused A limited examination of the visual system for an existing patient. The provider focuses on a specific eye-related concern or symptom. |
461 | $68 | $198 |
| Comprehensive eye exam, established patient A comprehensive examination of the visual system performed for a patient who has previously been seen by the provider. |
439 | $97 | $276 |
| Aflibercept eye injection (Eylea) | 412 | $693 | $2,000 |
| Compounded drug, not otherwise classified A medication prepared specifically for an individual patient by a pharmacist or physician, tailored to meet unique needs that cannot be fulfilled by commercially available products. |
250 | $69 | $110 |
| Retinal photography (fundus photo) This procedure involves taking photographs of the retina, the light-sensitive tissue at the back of the eye. It is used to document the condition of the eye's interior structures. |
155 | $26 | $82 |
| Retinal angiography with dye injection This procedure uses a special camera to examine the blood vessels in the retina after a dye has been injected into the body. |
154 | $108 | $307 |
| Tear duct plug insertion A procedure to insert a small plug into the tear duct opening to help retain tears on the eye surface. |
84 | $154 | $554 |
| Unclassified drug A medication that does not fit into standard HCPCS or CPT classification categories. |
80 | $464 | $1,312 |
| Retinal laser treatment for leaking blood vessels This procedure uses a laser to seal leaking blood vessels in the retina. It is performed to prevent vision loss caused by fluid leakage from damaged retinal vessels. |
58 | $287 | $1,250 |
| Comprehensive eye exam, new patient A comprehensive examination of the visual system performed for a new patient. |
50 | $111 | $321 |
| Office visit, established patient (30-39 min) A follow-up office visit for an existing patient lasting between 30 and 39 minutes. The visit involves medical evaluation and management of the patient's condition. |
44 | $110 | $281 |
| Office visit, established patient (10-19 min) An office visit for an existing patient lasting 10 to 19 minutes. The visit involves medical evaluation and management of the patient's condition. |
43 | $46 | $124 |
| New patient eye exam, problem focused A focused examination of the visual system performed during a new patient visit. |
26 | $61 | $184 |
| Visual field test, extended A test that maps your complete field of vision to detect blind spots or peripheral vision loss. Extended testing provides a more detailed assessment than a standard visual field exam. |
25 | $46 | $118 |
| Office visit for established patient An office visit for an existing patient that may not require the healthcare professional to be present. |
25 | $20 | $52 |
| Bevacizumab injection, 10 mg Administration of a 10 mg dose of bevacizumab medication via injection. |
25 | $52 | $92 |
| Fluorescein angiography of retina A special camera captures images of the blood vessels in the retina and the area between the white part of the eye and the retina after a dye is injected. |
24 | $210 | $582 |
| Office visit, established patient (20-29 min) An office visit for an existing patient lasting between 20 and 29 minutes. The visit involves medical evaluation and management of the patient's condition. |
17 | $72 | $194 |
Industry Payment Transparency
Open Payments through 2024 ↗Payment profile
Industry payments classified by relationship type. Not all payments are equal — research and consulting reflect different relationships than speaking programs or meals.
Payment trend by year
Annual totals from pharmaceutical and medical device companies.
Payments by company (2024)
All-time payments by company (2018-2024) ›
Associated products mentioned in payments ›
Most payments (100%) are for meals and travel — low-value interactions that are common across virtually all practicing physicians.
Geographic Context
3.1 mi
Data Sources
| Provider Registry | ✓ NPPES | Weekly updates |
| Medicare Enrollment | ✓ PECOS | Monthly updates |
| Practice Data | ✓ Medicare Util. | Annual (CY lag) |
| Industry Payments | ✓ Open Payments | CY 2024 |
| Disciplinary History | — Not public | N/A |
This provider has data in 4 of 4 available federal datasets, with a Data Coverage level of Very High. This reflects how much public data is available about a provider. How we calculate this →
Summary
Dr. Chang is a mixed practice specialist, with above-average Medicare volume (top 8% in CA), with low-engagement industry engagement, with 20 years of NPI registration.
This summary is auto-generated from federal data, describing data availability and patterns. Read our methodology →
Frequently Asked Questions
Is Dr. Chang experienced with injection, ranibizumab, 0.1 mg?
Does Dr. Chang receive payments from pharmaceutical companies?
How do Dr. Chang's costs compare to other ophthalmologists in Pasadena?
What does Data Coverage mean?
Is this data up to date?
Explore related providers
All data on this page is sourced verbatim from public federal records published by the U.S. Centers for Medicare & Medicaid Services (CMS): NPPES ↗, Open Payments ↗, Medicare Provider Utilization ↗, and PECOS. Publication is mandated by the Physician Payments Sunshine Act (§6002 ACA, 42 U.S.C. §1320a-7h) and the Freedom of Information Act.
This page is not medical advice, an endorsement, a recommendation, or a quality rating. Data Coverage reflects data completeness — how much federal information exists for this provider — not clinical performance, patient outcomes, or quality of care. Always verify information directly with the provider and consult a licensed clinician before making medical decisions.
Provider corrections: Provider portal · Privacy questions: Privacy Policy · Terms: Terms of Use · Methodology: Methodology