Total Payments
$4,734
2024 Payments
$1,421
Companies
26
Transactions
216
Medicare Patients
3,053
Medicare Billing
$883,281
Payment Breakdown by Category
Food & Beverage$4,676 (98.8%)
Education$58.62 (1.2%)
Payments by Nature
| Nature of Payment | Amount | Transactions | Share |
|---|---|---|---|
| Food and Beverage | $4,676 | 213 | 98.8% |
| Education | $58.62 | 3 | 1.2% |
Top Paying Companies
| Company | Total | Records | Latest Year |
|---|---|---|---|
| AstraZeneca Pharmaceuticals LP | $1,055 | 50 | $0 (2024) |
| Amgen Inc. | $681.27 | 25 | $0 (2024) |
| Otsuka America Pharmaceutical, Inc. | $398.74 | 18 | $0 (2024) |
| Fresenius USA Marketing, Inc. | $343.62 | 19 | $0 (2024) |
| Mallinckrodt Hospital Products Inc. | $323.92 | 13 | $0 (2024) |
| Janssen Pharmaceuticals, Inc | $260.61 | 8 | $0 (2024) |
| Bayer Healthcare Pharmaceuticals Inc. | $211.56 | 11 | $0 (2023) |
| Relypsa, Inc. | $208.30 | 20 | $0 (2019) |
| Vifor Pharma, Inc. | $167.29 | 7 | $0 (2024) |
| Otsuka Pharmaceutical Development & Commercialization, Inc. | $131.55 | 5 | $0 (2024) |
Payment History by Year
| Year | Amount | Transactions | Top Company |
|---|---|---|---|
| 2024 | $1,421 | 58 | AstraZeneca Pharmaceuticals LP ($258.31) |
| 2023 | $1,138 | 45 | AstraZeneca Pharmaceuticals LP ($234.07) |
| 2022 | $384.08 | 21 | AstraZeneca Pharmaceuticals LP ($117.12) |
| 2021 | $658.88 | 31 | AstraZeneca Pharmaceuticals LP ($185.71) |
| 2020 | $376.66 | 21 | AstraZeneca Pharmaceuticals LP ($260.26) |
| 2019 | $460.12 | 27 | Janssen Pharmaceuticals, Inc ($223.66) |
| 2018 | $163.98 | 6 | ZOLL Services LLC (A/K/A ZOLL LifeCor Corp) ($70.83) |
| 2017 | $131.14 | 7 | Fresenius USA Marketing, Inc. ($40.34) |
All Payment Transactions
216 individual payment records from CMS Open Payments — Page 1 of 9
| Date | Company | Product | Nature | Form | Amount | Type |
|---|---|---|---|---|---|---|
| 12/19/2024 | Otsuka America Pharmaceutical, Inc. | JYNARQUE (Drug) | Food and Beverage | In-kind items and services | $22.92 | General |
| Category: NEPHROLOGY | ||||||
| 12/12/2024 | Travere Therapeutics, Inc. | — | Food and Beverage | In-kind items and services | $35.21 | General |
| 12/06/2024 | Mallinckrodt Hospital Products Inc. | ACTHAR (Biological) | Food and Beverage | In-kind items and services | $31.89 | General |
| Category: IMMUNOLOGY | ||||||
| 11/23/2024 | AstraZeneca Pharmaceuticals LP | FARXIGA (Drug) | Food and Beverage | In-kind items and services | $28.77 | General |
| Category: Cardiovascular and Metabolism | ||||||
| 11/22/2024 | Lilly USA, LLC | JARDIANCE (Drug) | Food and Beverage | In-kind items and services | $30.99 | General |
| Category: Diabetes | ||||||
| 11/21/2024 | Amgen Inc. | TAVNEOS (Drug) | Food and Beverage | In-kind items and services | $17.05 | General |
| Category: Inflammation | ||||||
| 11/16/2024 | Vifor Pharma, Inc. | Veltassa (Drug) | Food and Beverage | In-kind items and services | $34.70 | General |
| Category: Hyperkalemia | ||||||
| 11/09/2024 | Mallinckrodt Hospital Products Inc. | ACTHAR (Biological) | Food and Beverage | In-kind items and services | $34.88 | General |
| Category: IMMUNOLOGY | ||||||
| 11/08/2024 | AstraZeneca Pharmaceuticals LP | FARXIGA (Drug) | Food and Beverage | In-kind items and services | $28.35 | General |
| Category: Cardiovascular and Metabolism | ||||||
| 11/05/2024 | Novartis Pharmaceuticals Corporation | Fabhalta (Drug) | Food and Beverage | In-kind items and services | $34.76 | General |
| Category: Immunology | ||||||
| 10/24/2024 | Novo Nordisk Inc | Ozempic (Drug), Rybelsus | Food and Beverage | In-kind items and services | $19.10 | General |
| Category: Diabetes | ||||||
| 10/18/2024 | Mallinckrodt Hospital Products Inc. | ACTHAR (Biological) | Food and Beverage | In-kind items and services | $27.55 | General |
| Category: IMMUNOLOGY | ||||||
| 10/10/2024 | Fresenius USA Marketing, Inc. | Velphoro (Drug) | Food and Beverage | In-kind items and services | $22.32 | General |
| Category: Phosphate binder for ESRD | ||||||
| 10/03/2024 | Novo Nordisk Inc | Ozempic (Drug), Rybelsus | Food and Beverage | In-kind items and services | $19.10 | General |
| Category: Diabetes | ||||||
| 09/28/2024 | Mallinckrodt Hospital Products Inc. | ACTHAR (Biological) | Food and Beverage | In-kind items and services | $23.61 | General |
| Category: IMMUNOLOGY | ||||||
| 09/13/2024 | AstraZeneca Pharmaceuticals LP | FARXIGA (Drug) | Food and Beverage | In-kind items and services | $27.96 | General |
| Category: Cardiovascular and Metabolism | ||||||
| 09/07/2024 | Novartis Pharmaceuticals Corporation | Fabhalta (Drug) | Food and Beverage | In-kind items and services | $31.55 | General |
| Category: Immunology | ||||||
| 09/05/2024 | Vifor Pharma, Inc. | Veltassa (Drug) | Food and Beverage | In-kind items and services | $30.50 | General |
| Category: Hyperkalemia | ||||||
| 08/30/2024 | Novartis Pharmaceuticals Corporation | Fabhalta (Drug) | Food and Beverage | In-kind items and services | $30.94 | General |
| Category: Immunology | ||||||
| 08/29/2024 | AstraZeneca Pharmaceuticals LP | FARXIGA (Drug) | Food and Beverage | In-kind items and services | $21.35 | General |
| Category: Cardiovascular and Metabolism | ||||||
| 08/22/2024 | Boehringer Ingelheim Pharmaceuticals, Inc. | JARDIANCE (Drug) | Food and Beverage | In-kind items and services | $24.91 | General |
| Category: DIABETES | ||||||
| 08/16/2024 | CALLIDITAS THERAPEUTICS US INC. | TARPEYO (Drug) | Food and Beverage | In-kind items and services | $24.97 | General |
| Category: Nephrology | ||||||
| 08/16/2024 | OPKO Pharmaceuticals, LLC | RAYALDEE (Drug) | Education | In-kind items and services | $18.87 | General |
| Category: NEPHROLOGY | ||||||
| 08/09/2024 | Amgen Inc. | KRYSTEXXA (Biological) | Food and Beverage | In-kind items and services | $14.74 | General |
| Category: Inflammation/Rare Disease | ||||||
| 08/09/2024 | Amgen Inc. | KRYSTEXXA (Biological) | Food and Beverage | In-kind items and services | $14.41 | General |
| Category: Inflammation/Rare Disease | ||||||
Medicare Billing by Year
| Year | Procedures | Beneficiaries | Services | Submitted | Medicare Paid |
|---|---|---|---|---|---|
| 2023 | 10 | 648 | 1,370 | $525,936 | $177,821 |
| 2022 | 11 | 723 | 1,656 | $581,715 | $189,859 |
| 2021 | 14 | 802 | 2,048 | $673,749 | $255,424 |
| 2020 | 13 | 880 | 2,511 | $689,151 | $260,176 |
Total Patients
3,053
Total Services
7,585
Medicare Billing
$883,281
Procedure Codes
49
All Medicare Procedures & Services
49 procedure records from CMS Medicare Utilization — Page 1 of 2
| HCPCS | Description | Setting | Year | Patients | Services | Charges | Medicare Paid | Ratio |
|---|---|---|---|---|---|---|---|---|
| 90960 | Dialysis services, 4 or more physician visits per month (20 years or older) | Office | 2023 | 35 | 169 | $133,510 | $54,539 | 40.9% |
| 99214 | Established patient office or other outpatient visit, 30-39 minutes | Office | 2023 | 143 | 327 | $97,446 | $23,468 | 24.1% |
| 99291 | Critical care, first 30-74 minutes | Facility | 2023 | 45 | 122 | $76,372 | $23,153 | 30.3% |
| 99233 | Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | Facility | 2023 | 104 | 210 | $55,020 | $21,996 | 40.0% |
| 99232 | Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | Facility | 2023 | 108 | 211 | $36,714 | $15,002 | 40.9% |
| 99223 | Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | Facility | 2023 | 72 | 76 | $29,032 | $11,413 | 39.3% |
| 99215 | Established patient office or other outpatient visit, 40-54 minutes | Office | 2023 | 56 | 122 | $50,752 | $9,642 | 19.0% |
| 90961 | Dialysis services, 2-3 physician visits per month (20 years or older) | Office | 2023 | 15 | 36 | $23,760 | $9,586 | 40.3% |
| 90935 | Hemodialysis procedure with physician evaluation | Facility | 2023 | 47 | 74 | $11,692 | $4,601 | 39.4% |
| 99205 | New patient office or other outpatient visit, 60-74 minutes | Office | 2023 | 23 | 23 | $11,638 | $4,422 | 38.0% |
| 90960 | Dialysis services, 4 or more physician visits per month (20 years or older) | Office | 2022 | 47 | 188 | $152,920 | $60,456 | 39.5% |
| 99232 | Follow-up hospital inpatient care per day, typically 25 minutes | Facility | 2022 | 149 | 430 | $68,455 | $27,641 | 40.4% |
| 99214 | Established patient office or other outpatient visit, 30-39 minutes | Office | 2022 | 149 | 333 | $100,665 | $22,663 | 22.5% |
| 99291 | Critical care, first 30-74 minutes | Facility | 2022 | 42 | 117 | $75,474 | $22,225 | 29.4% |
| 99233 | Follow-up hospital inpatient care per day, typically 35 minutes | Facility | 2022 | 92 | 185 | $42,114 | $16,844 | 40.0% |
| 99223 | Initial hospital inpatient care per day, typically 70 minutes | Facility | 2022 | 81 | 83 | $36,556 | $14,363 | 39.3% |
| 90961 | Dialysis services, 2-3 physician visits per month (20 years or older) | Office | 2022 | 20 | 40 | $27,060 | $10,975 | 40.6% |
| 90935 | Hemodialysis procedure with physician evaluation | Facility | 2022 | 74 | 144 | $23,220 | $9,247 | 39.8% |
| 99215 | Established patient office or other outpatient visit, 40-54 minutes | Office | 2022 | 41 | 105 | $44,639 | $3,041 | 6.8% |
| 99204 | New patient office or other outpatient visit, 45-59 minutes | Office | 2022 | 15 | 15 | $5,820 | $1,665 | 28.6% |
| 99443 | Telephone medical discussion with physician, 21-30 minutes | Office | 2022 | 13 | 16 | $4,792 | $740.10 | 15.4% |
| 90960 | Dialysis services (4 or more physician visits per month), patient 20 years of age and older | Office | 2021 | 40 | 227 | $181,980 | $73,032 | 40.1% |
| 99214 | Established patient outpatient visit, total time 30-39 minutes | Office | 2021 | 159 | 364 | $110,216 | $40,418 | 36.7% |
| 99232 | Subsequent hospital inpatient care, typically 25 minutes per day | Facility | 2021 | 173 | 608 | $95,435 | $38,701 | 40.6% |
| 99291 | Critical care delivery critically ill or injured patient, first 30-74 minutes | Facility | 2021 | 61 | 150 | $95,000 | $28,468 | 30.0% |
About Dr. Warren Chang, MD
Dr. Warren Chang, MD is a Nephrology healthcare provider based in Daly City, California. This provider has been registered with the National Plan and Provider Enumeration System (NPPES) since 03/27/2006. The National Provider Identifier (NPI) number assigned to this provider is 1083674550.
According to the Centers for Medicare & Medicaid Services (CMS) Open Payments database, Dr. Warren Chang, MD has received a total of $4,734 in payments from pharmaceutical and medical device companies, with $1,421 received in 2024. These payments were reported across 216 transactions from 26 companies. The most common payment nature is "Food and Beverage" ($4,676).
As a Medicare-enrolled provider, Chang has provided services to 3,053 Medicare beneficiaries, totaling 7,585 services with total Medicare billing of $883,281. Data is available for 4 years (2020–2023), covering 49 distinct procedure/service records.
Ad
Practice Information
- Specialty Nephrology
- Location Daly City, CA
- Active Since 03/27/2006
- Last Updated 08/26/2019
- Taxonomy Code 207RN0300X
- Entity Type Individual
- Practice Solo Practitioner
- NPI Number 1083674550
Products in Payments
- LOKELMA (Drug) $548.94
- JYNARQUE (Drug) $530.29
- FARXIGA (Drug) $506.53
- Veltassa (Drug) $375.59
- Velphoro (Drug) $322.62
- ACTHAR (Biological) $294.83
- Parsabiv (Drug) $226.81
- Kerendia (Drug) $211.56
- INVOKANA (Drug) $208.07
- Aranesp (Biological) $149.47
- TARPEYO (Drug) $129.91
- KRYSTEXXA (Biological) $129.25
- Parsabiv (Biological) $118.47
- JARDIANCE (Drug) $113.74
- Ozempic (Drug) $100.59
- Fabhalta (Drug) $97.25
- LifeVest (Device) $70.83
- EPOGEN (Biological) $59.86
- RAYALDEE (Drug) $58.62
- XARELTO (Drug) $52.54
Explore
Data Sources
Provider data from NPPES. Payment data from CMS Open Payments. Medicare data from CMS Medicare Provider Utilization. All data is public and updated periodically.
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