Medicare Enrolled
Dr. Ruby Chang, M.D.
Radiation Oncology · Walnut Creek, CA
Practice pattern: Mixed Practice
— Diverse clinical practice across multiple procedure types
Low-engagement
Very High
DATA COVERAGE
Data in 4 of 4 federal sources
Measures public federal data availability — not provider quality
Informational, not a quality rating.
This page presents federal public records about Dr. Chang from CMS (NPPES, Open Payments, Medicare Provider Utilization, PECOS). It is not medical advice, an endorsement, or a judgment of clinical quality. Always consult the provider directly and a licensed clinician for medical decisions. Read methodology →
Are you Dr. Chang?
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What this data tells you about Dr. Chang
Dr. Ruby Chang is a radiation oncology specialist in Walnut Creek, CA, with 19 years of NPI registration. Based on federal Medicare data, Dr. Chang performed 33,037 Medicare services across 9,409 unique beneficiaries.
Between the years covered by Open Payments, Dr. Chang received a total of $121 from 5 pharmaceutical and/or device companies across 6 individual payments. These payments are legal, publicly disclosed under the federal Sunshine Act, and common in radiation oncology. 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.
✓ 19 years in practice
▲ Top 5% volume in CA
$121 industry payments
Medicare Practice Summary
Medicare Utilization ↗33,037
Medicare services
Top 5% in CA for radiation oncology
9,409
Unique beneficiaries
$28
Avg. Medicare payment
Medicare patients only (65+ / disabled) · How to read this →
~1,739 Medicare services per year of practice
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 |
|---|---|---|---|
| MRI contrast dye injection (gadoterate) Administration of gadoterate meglumine, a contrast agent, in a 0.1 ml dose. |
17,810 | $0 | $1 |
| Contrast dye for imaging (iodine-based) A contrast agent containing 300-399 mg/ml of iodine used to enhance imaging studies. It is administered per milliliter to improve the visibility of internal structures. |
5,970 | $0 | $0 |
| 3D screening mammography (tomosynthesis) A screening imaging test of the breast using 3D technology to detect potential abnormalities. |
3,661 | $57 | $250 |
| Screening mammography An X-ray of the breast used to detect breast cancer in women who have no signs or symptoms of the disease. |
3,649 | $140 | $296 |
| Digital breast tomosynthesis (3D mammogram) A specialized imaging test that creates three-dimensional pictures of the breast tissue to help detect abnormalities. |
355 | $45 | $170 |
| Diagnostic mammography of 1 breast An X-ray examination of one breast to evaluate specific breast symptoms or abnormalities. |
244 | $100 | $285 |
| Limited ultrasound of 1 breast A focused ultrasound examination of a single breast to evaluate specific areas of concern. |
231 | $75 | $199 |
| Diagnostic mammography of both breasts | 204 | $128 | $357 |
| MRI scan of both breasts A magnetic resonance imaging test that creates detailed pictures of both breasts to help evaluate breast tissue. |
107 | $298 | $1,500 |
| Chest X-ray, 2 views An X-ray imaging test of the chest that captures two different angles to visualize the lungs, heart, and chest wall. |
97 | $25 | $92 |
| Bone density scan (DEXA) A test that uses low-dose X-rays to measure bone mineral density in the hip, pelvis, and spine. It helps assess bone strength and risk of fractures. |
91 | $42 | $293 |
| Chest X-ray, 1 view An X-ray image of the chest taken from a single angle. This imaging test is used to visualize the structures within the chest cavity. |
80 | $7 | $28 |
| CT scan of chest, without contrast A computed tomography scan of the chest area that uses X-rays to create detailed images without the use of contrast dye. |
53 | $117 | $612 |
| Bone density scan (DEXA) of forearm, finger, hand, or foot A DEXA scan measures bone mineral density in the forearm, finger, hand, or foot. This test helps assess bone strength and risk of fracture. |
50 | $34 | $87 |
| CT scan of abdomen and pelvis with contrast A CT scan that uses dye to create detailed images of the abdomen and pelvis. This imaging test helps doctors examine internal organs and structures in these areas. |
38 | $262 | $1,000 |
| Breast biopsy with ultrasound-guided localization device placement This procedure involves taking a tissue sample from a breast growth and placing a marker device to locate it, guided by ultrasound imaging. |
33 | $429 | $2,032 |
| X-ray of lower and sacral spine, 2-3 views An X-ray imaging test that captures 2 to 3 views of the lower back and sacral spine to visualize the bones and joints in this area. |
28 | $34 | $122 |
| Shoulder X-ray, 2+ views An X-ray imaging test of the shoulder joint using at least two different angles to visualize the bones and surrounding structures. |
28 | $28 | $92 |
| Foot X-ray, 3+ views An X-ray imaging test of the foot that captures at least three different views to evaluate the bones and joints. |
27 | $28 | $93 |
| CT scan of chest with contrast A computed tomography scan of the chest using a contrast dye to enhance the visibility of internal structures. |
23 | $102 | $768 |
| CT scan of abdomen and pelvis, without contrast A computed tomography scan that creates detailed images of the abdominal and pelvic organs. The procedure is performed without the use of intravenous contrast dye. |
22 | $156 | $755 |
| Limited retroperitoneal ultrasound A focused ultrasound exam of the area behind the abdominal cavity to evaluate specific structures. |
20 | $49 | $209 |
| Knee X-ray, 3 views An X-ray imaging test of the knee joint that captures three different angles to evaluate the bones and surrounding structures. |
19 | $32 | $111 |
| Ultrasound of head and neck soft tissue This procedure uses sound waves to create images of the soft tissues in the head and neck area. It allows for the visualization of structures beneath the skin without using radiation. |
19 | $68 | $236 |
| CT scan of head/brain, without contrast A CT scan uses X-rays to create detailed images of the head or brain without the use of contrast dye. |
18 | $85 | $483 |
| Complete breast ultrasound, 1 breast A complete ultrasound examination of one breast to visualize internal structures. |
18 | $89 | $367 |
| Hip X-ray, 2-3 views An X-ray imaging test of the hip joint using two to three different angles to visualize the bones and surrounding structures. |
17 | $41 | $125 |
| CT scan of heart for calcium evaluation A CT scan of the heart used to evaluate calcium levels in the blood vessels. |
17 | $81 | $260 |
| Breast biopsy with localization device using X-ray A procedure to remove a sample of breast tissue for testing, using X-ray guidance to place a device that marks the location of the first growth. |
15 | $424 | $2,046 |
| CT scan of chest blood vessels with contrast A CT scan that uses contrast dye to create detailed images of the blood vessels in the chest. |
15 | $68 | $279 |
| Limited abdominal ultrasound A focused ultrasound examination of the abdomen to evaluate specific organs or areas. This procedure uses sound waves to create images of internal structures. |
15 | $72 | $208 |
| CT scan of abdomen and pelvis with contrast A CT scan of the abdomen and pelvis using contrast dye before and after administration to visualize internal structures. |
13 | $310 | $1,291 |
| Transvaginal pelvic ultrasound An ultrasound exam using a probe inserted into the vagina to image the uterus, ovaries, fallopian tubes, cervix, and surrounding pelvic structures. |
13 | $98 | $245 |
| Complete pelvic ultrasound An imaging test using sound waves to create pictures of the organs and structures within the pelvis. |
13 | $85 | $243 |
| CT scan of upper spine, without contrast A CT scan uses X-rays to create detailed images of the upper spine. This procedure is performed without the use of contrast dye. |
12 | $39 | $145 |
| Complete ultrasound of retroperitoneum An ultrasound examination of the structures located behind the abdominal cavity. |
12 | $77 | $257 |
How to read this data: This reflects Medicare patients only (typically 65+). Payment amounts are what Medicare paid the provider, not your out-of-pocket cost. A higher procedure volume generally indicates more experience with that procedure.
Industry Payment Transparency
Open Payments through 2024 ↗$121
Total received (2019-2024)
Avg $30/year across 4 years
Bottom 39% in CA for radiation oncology
5
Companies
6
Individual payments
All payments are legal and publicly reported · Not evidence of wrongdoing · How to interpret →
Payment profile
Industry payments classified by relationship type. Not all payments are equal — research and consulting reflect different relationships than speaking programs or meals.
Meals & Travel
Food, beverages, travel, and lodging — typically low-value
$121 (100.0%)
Payment trend by year
Annual totals from pharmaceutical and medical device companies.
2024
$23
2021
$16
2020
$35
2019
$48
Payments by company (2024)
Consulting
Speaking
Meals & Travel
Research
Incyte Corporation
$23
Top 3 companies account for 100.0% of 2024 payments
All-time payments by company (2019-2024) ›
Incyte Corporation
$38
Janssen Biotech, Inc.
$24
Puma Biotechnology, Inc.
$24
Eisai Inc.
$19
MAYNE PHARMA INC.
$16
Top 3 companies account for 71.0% of all-time payments
Associated products mentioned in payments ›
Erleada · JAKAFI · Lenvima · Nerlynx
Should you be concerned? Payments from pharmaceutical and device companies are legal and common — 57% of U.S. physicians receive at least one. They often reflect legitimate consulting, research, or education. What matters is whether a recommended drug or device appears in your doctor's payment records. If so, consider asking your doctor about it. How to interpret this data →
Most payments (100%) are for meals and travel — low-value interactions that are common across virtually all practicing physicians.
Geographic Context
Radiation oncologists within 10 mi
331
Per 100K population
28.5
County median income
$125,727
Nearest hospital
JOHN MUIR MEDICAL CENTER - WALNUT CREEK CAMPUS
0.0 mi
0.0 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 5% in CA), with low-engagement industry engagement, with 19 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 mri contrast dye injection (gadoterate)?
Based on Medicare claims data, Dr. Chang performed 17,810 mri contrast dye injection (gadoterate) services. Research suggests that higher procedure volume is often associated with better outcomes, particularly for complex procedures. Note that Medicare data only captures patients aged 65 and older, so the total practice volume across all patients is likely higher.
Does Dr. Chang receive payments from pharmaceutical companies?
Yes. Dr. Chang received a total of $121 from 5 companies across 6 individual payments. These payments are legal, publicly disclosed under the federal Sunshine Act, and common among physicians — 57% of all U.S. physicians receive at least one industry payment. Patients may wish to ask their doctor about these relationships, especially if a recommended drug or device appears in the payment records.
How do Dr. Chang's costs compare to other radiation oncologists in Walnut Creek?
Dr. Chang's average Medicare payment per service is $28. Note that these figures represent what Medicare pays, not your out-of-pocket cost, which depends on your specific insurance plan and deductible. Procedure-level data above shows both what was submitted and what Medicare paid for each service type.
What does Data Coverage mean?
Data Coverage (currently Very High for Dr. Chang) measures how much public federal data is available about a provider. It is not a quality rating. A "Very High" or "High" level means the provider has data across multiple federal sources (NPPES, PECOS, Medicare Utilization, Open Payments), indicating a long track record of practice, Medicare participation, and industry disclosure. A "Low" or "Moderate" level may simply mean the provider is newer, does not see Medicare patients, or has not received any industry payments — none of which are inherently negative. Read our full methodology →
Is this data up to date?
Each data source has its own update cycle. Provider registry data (NPPES) is updated weekly. Medicare enrollment (PECOS) is updated monthly. Medicare practice data has a ~2 year lag — the most recent available is typically 2 years prior. Industry payment data (Open Payments) is published annually, usually in June, covering the prior calendar year. We display the data date prominently on each section so you always know how current it is. See our data freshness policy →
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About this page
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.
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