William Chang, MD
NPI 1003236688 · Critical Care Medicine (Internal Medicine) Physician · Monterey Park, CA
Enrolled with Medicare as Practitioner - Critical Care (intensivists) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Chang, MD is a Critical Care Medicine (Internal Medicine) Physician provider in Monterey Park, CA (NPI 1003236688).
Provider details
- NPI number
- 1003236688
- Entity type
- Individual
- Primary specialty
- Critical Care Medicine (Internal Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A140305 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
12 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
3,990 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) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 2,107 | $122 |
| Critical Care, First 30-74 Minutes99291 | 636 | $217 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 261 | $138 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 209 | $81 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 147 | $179 |
| Telephone Medical Discussion With Physician, 21-30 Minutes99443 | 131 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 27 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Fluticasone/Umeclidin/Vilanterbrand: Trelegy Ellipta | 304 | 60 |
| Albuterol Sulfatebrand: Albuterol Sulfate Hfa | 279 | 82 |
| Montelukast Sodium | 200 | 55 |
| Umeclidinium Brm/Vilanterol Trbrand: Anoro Ellipta | 172 | 40 |
| Budesonide/Glycopyr/Formoterolbrand: Breztri Aerosphere | 153 | 38 |
| Fluticasone Propionate | 101 | 36 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,941 across 65 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
Additional practice locations (1)
- 8700 Beverly BlvdWest Hollywood, CA 90048-1804Phone: (310) 423-3277
Registry dates
- Enumerated
- 2014-04-22
- Last updated
- 2021-08-18
- Certified
- 2021-08-18
Frequently asked questions
- What is William Chang's NPI number?
- William Chang's National Provider Identifier (NPI) is 1003236688, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Chang's specialty?
- William Chang is listed in the NPPES registry with a primary specialty of Critical Care Medicine (Internal Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is William Chang located?
- William Chang's practice location on file with NPPES is 500 N Garfield Ave Ste 204, Monterey Park, CA 91754-1242.
- What is William Chang's phone number?
- The practice phone number listed in the NPPES registry for William Chang is (626) 280-4393.
- Does William Chang accept Medicare?
- William Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Chang's NPI active?
- Yes — William Chang's NPI (1003236688) is active in the NPPES registry as of the last update on 2021-08-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.