Dr. William Weiming Chang, DO
- Medicare services, 2024
- 5,736
- Medicare patients, 2024
- 628
- Part D claims, 2024
- 5,085
- MIPS score, 2024
- 80
- Hospital affiliations
- 4
- Practice address
- 30230 Rancho Viejo Rd, San Juan Capistrano, CA 92675
- Practice phone
- Call (949) 443-4303
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Paloma Medical Group Inc
San Juan Capistrano, California
Find Dr. Chang's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. William Weiming Chang is a pulmonologist in San Juan Capistrano, California
Dr. Chang practices at Paloma Medical Group Inc in San Juan Capistrano, California.
Dr. Chang's NPI, 1417902149, was assigned on May 23, 2006. Dr. Chang graduated from Michigan State University College Of Osteopathic Medicine in 2000. Dr. Chang holds California license 20A7942.
- NPI
- 1417902149NPI Registry (opens in a new tab)
- Medicare PAC ID
- 3274639091
- NPI enumeration date
- May 23, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
- Practice phone
- (949) 443-4303
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 52
- Medical school graduation
- 2000
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. William Weiming Chang practices at Paloma Medical Group Inc in San Juan Capistrano, California
Dr. Chang's primary practice is Paloma Medical Group Inc, at 30230 Rancho Viejo Rd, San Juan Capistrano, CA 92675 in Orange County. The practice phone is (949) 443-4303.
- Paloma Medical Group Inc30230 Rancho Viejo Rd, San Juan Capistrano, CA 92675 · Orange CountyPhone(949) 443-4303
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. William Weiming Chang is affiliated with 10 sites of care and 4 medical groups
Dr. Chang's primary practice is Paloma Medical Group Inc in San Juan Capistrano, California. Dr. Chang is also affiliated with Hoag Hospital Newport Beach. The medical group on file is UCI Health Physicians. Dmand AI also links Dr. Chang to 3 more hospitals, 4 group practices and clinics, 3 medical groups and 1 home health agency, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. William Weiming Chang's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Chang practices, 9 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Paloma Medical Group Inc | Available with a free account |
| +9 more sites and 3 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. William Weiming Chang is one of 1,339 pulmonologists in California
Pulmonary disease is Dr. Chang's primary specialty in the NPI Registry, under taxonomy code 207RP1001X. Dr. Chang is board certified in critical care medicine by the American Board of Internal Medicine. Dr. Chang is licensed in California.
Specialties and state licenses
- Pulmonary disease, CaliforniaPrimary
Clinical focus
Dmand AI lists acute sinusitis, asthma, bronchitis, chronic lung disease, chronic obstructive pulmonary disease (COPD), chronic respiratory failure, chronic sinusitis and hypersomnia among the conditions Dr. Chang treats.
Pulmonologists near Dr. Chang
Counts of pulmonologists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. William Weiming Chang billed Medicare for 5,736 services in 2024
CMS data shows 5,736 Medicare services from Dr. Chang across 25 procedure codes in 2024, for 628 Medicare patients. Medicare paid $419,956 for them.
Dr. Chang's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 3,1482024: 2,56319%
- Tests and treatments
- 2023: 1,6012024: 2,20338%
- Other services
- 2023: 1152024: 970743%
Where Dr. Chang's Medicare services took place, 2024
- In an office5,49996%
- In a facility2374%
Dr. Chang compared with the California median for pulmonologists, 2024
- Dr. Chang
- California median
- Medicare services
- 5,736vs 6498.8 times
- Medicare patients
- 628vs 2722.3 times
- Part D claims
- 4,635vs 42111.0 times
Medians across 1,263 pulmonologists in California with Dmand AI profiles that report each measure.
Dr. Chang's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
Need commercial claims for Dr. Chang?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Chang and other pulmonologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. William Weiming Chang treated 628 Medicare patients in 2024, average age 76
CMS counts 628 Medicare patients who saw Dr. Chang in 2024. The largest group is 75 to 84, with 259 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 23% are also on Medicaid. Their average risk score is 1.72, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Chang's median patient age at 70, with 51% women.
Dr. Chang's Medicare patients by age, 2024
Dr. Chang's Medicare patients by sex, 2024
- Women33754%
- Men29146%
Chronic conditions among Dr. Chang's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis54%
- COPD46%
- Asthma39%
- Ischemic heart disease34%
- Diabetes33%
- Mood disorders29%
Share of Medicare patients with each condition. A patient can have several.
Dr. Chang's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 70
Patient panel by sex, all payers
- Women51%
- Men49%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. William Weiming Chang wrote 5,085 Medicare Part D claims in 2024
In 2024, Dr. Chang wrote 5,085 Medicare Part D claims for 748 patients. 63% of them were for generic drugs. CMS names the drug for 4,635 of them, across 69 drugs with 11 or more claims each, at $2,266,404 in total drug cost. In 2023, CMS named 3,995 claims across 68 drugs.
Dr. Chang's Part D claims by kind of drug, 2024
- Generic3,201 claims63%
- Brand-name and other1,884 claims37%
Dr. Chang's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Chang's Part D claims, 2024
- Antibiotics7%358 of 5,085 claims
- Antipsychotics, patients 65 and over0%12 of 5,085 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 3,9952024: 4,63516%
Drugs named by CMS: 69 in 2024, 68 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
Dr. William Weiming Chang scored 80 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 80 out of 100 for Dr. Chang for performance year 2024, reported as part of a group. Dr. Chang accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Dr. Chang as offering telehealth.
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
Dr. Chang's MIPS scores, performance year 2024
- 80of 100Final score
- 59.7of 100Quality
- 40of 100Improvement Activities
- 67of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Sources: Doctors and Clinicians National Downloadable File (CMS); and Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026
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Dr. William Weiming Chang received $20,040 in industry payments from 2016 to 2025
CMS Open Payments shows 1,068 general payments to Dr. Chang from 65 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 98% of the total. GlaxoSmithKline, LLC. paid the most, $5,026.
General payments to Dr. Chang by program year, 2016 to 2025
General payments to Dr. Chang by kind, 2016 to 2025
- Food and beverage$19,64498%
- Education$3622%
- Speaker and faculty fees$330%
Companies that paid Dr. Chang the most, 2016 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. William Weiming Chang has 1 award and honors on record
Dmand AI lists 1 award for Dr. Chang, most recently CMS Stage 1 EHR in 2013.
Awards and honors for Dr. Chang
- 2013
- CMS Stage 1 EHR
Source: Dmand AI Professional Profile Data
Dr. William Weiming Chang graduated from Michigan State University College Of Osteopathic Medicine
Dr. Chang graduated from Michigan State University College Of Osteopathic Medicine in 2000. Dr. Chang is a member of AOA.
- Medical school
- Board certified in critical care medicine
- Board certified in internal medicine
- Board certified in pulmonary disease
Source: Dmand AI Professional Profile Data
Dr. William Weiming Chang accepts plans from 15 insurance carriers
Dr. Chang is in network with 15 carriers, including Aetna, Blue Cross Blue Shield of Michigan and Elevance. Medicare plans come from the most carriers, 10. Check the plan with the practice before a visit.
- Aetna
- Blue Cross Blue Shield of Michigan
- Elevance
- United Healthcare
- HCSC
- Humana
- Blue Cross Blue Shield of Massachusetts
- Molina
- +7 more carriersWith a free account
Plan types Dr. Chang accepts, by number of carriers
- Medicare10
- PPO10
- HMO8
- EPO4
- POS3
Source: Dmand AI Insurance Network Data
Sources for Dr. William Weiming Chang's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Clinician Public Reporting: Overall MIPS Performance (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Awards and committee roles | Dmand AI Professional Profile Data |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| Insurance carriers and plan types | Dmand AI Insurance Network Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. William Weiming Chang
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. William Weiming Chang's NPI number?
Dr. William Weiming Chang's NPI number is 1417902149. It was assigned on May 23, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. William Weiming Chang?
Dr. William Weiming Chang is a pulmonologist in San Juan Capistrano, California. The primary specialty in the NPI Registry is Pulmonary Disease Physician (taxonomy code 207RP1001X).
Where does Dr. William Weiming Chang practice?
Dr. Chang practices at 30230 Rancho Viejo Rd, San Juan Capistrano, CA 92675. Dr. Chang's primary practice is Paloma Medical Group Inc in San Juan Capistrano, California. Dmand AI also links Dr. Chang to 3 hospitals, 4 group practices and clinics, 3 medical groups and 1 home health agency.
What is Dr. William Weiming Chang's office phone number?
The practice phone on file for Dr. Chang is (949) 443-4303.
What is Dr. William Weiming Chang's medical license number?
Dr. Chang holds California license 20A7942.
Which hospitals is Dr. William Weiming Chang affiliated with?
Dr. Chang is affiliated with Hoag Hospital Newport Beach. Dmand AI links Dr. Chang to 3 more hospitals.
What medical group is Dr. William Weiming Chang part of?
Dr. Chang is linked to UCI Health Physicians. Dmand AI links Dr. Chang to 3 more medical groups.
Does Dr. William Weiming Chang accept Medicare?
Yes. CMS data shows Dr. Chang billed Medicare for 5,736 services in 2024, and Dr. Chang accepts Medicare assignment.
Does Dr. William Weiming Chang offer telehealth?
Yes. The CMS Doctors and Clinicians file lists Dr. Chang as offering telehealth services.
What is Dr. William Weiming Chang's MIPS score?
Dr. Chang's MIPS final score for performance year 2024 is 80 out of 100, reported as part of a group.
Show 8 more questionsShow fewer questions
How many Medicare patients does Dr. William Weiming Chang see?
CMS counts 628 Medicare patients who saw Dr. Chang in 2024, with an average age of 76.
Is Dr. William Weiming Chang board certified?
Yes. Dr. Chang is board certified in critical care medicine by the American Board of Internal Medicine.
What services does Dr. William Weiming Chang bill to Medicare?
In 2024, Dr. Chang's most billed Medicare services were office visit, established patient (99215), medicare service (G2211) and lung function service (94664).
Where did Dr. William Weiming Chang go to medical school?
Dr. Chang graduated from Michigan State University College Of Osteopathic Medicine in 2000.
What drugs does Dr. William Weiming Chang prescribe most?
In 2024 Medicare Part D data, Dr. Chang's most prescribed drugs by claims were Albuterol Sulfate Hfa, Fluticasone Propionate and Trelegy Ellipta.
Has Dr. William Weiming Chang received payments from drug or device companies?
CMS Open Payments shows $20,040 in general payments to Dr. Chang from 65 companies from 2016 to 2025. The largest total came from GlaxoSmithKline, LLC.
How long has Dr. William Weiming Chang been practicing?
Dr. Chang graduated from medical school in 2000, 26 years ago.
What insurance does Dr. William Weiming Chang accept?
Dr. Chang is in network with 15 carriers, including Aetna, Blue Cross Blue Shield of Michigan and Elevance. Medicare plans come from the most carriers, 10. Check the plan with the practice before a visit.
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