Ronald Chang, M.D.
NPI 1861810863 · Hospitalist Physician · Pomona, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Ronald Chang, M.D. is a Hospitalist Physician provider in Pomona, CA (NPI 1861810863).
Provider details
- NPI number
- 1861810863
- Entity type
- Individual
- Primary specialty
- Hospitalist PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- A141360 (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
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
665 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 | 362 | $122 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 156 | $179 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 147 | $119 |
Typical Medicare-allowed amounts for these services range $119–$179 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 9 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Furosemide | 23 | 18 |
| Atorvastatin Calcium | 18 | 13 |
| Apixabanbrand: Eliquis | 18 | — |
| Amlodipine Besylate | 16 | 13 |
| Metoprolol Tartrate | 14 | — |
| Tamsulosin Hcl | 14 | — |
| Hydrocodone/Acetaminophen |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$42 across 2 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
Registry dates
- Enumerated
- 2014-04-07
- Last updated
- 2018-10-03
Frequently asked questions
- What is Ronald Chang's NPI number?
- Ronald Chang's National Provider Identifier (NPI) is 1861810863, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Ronald Chang's specialty?
- Ronald Chang is listed in the NPPES registry with a primary specialty of Hospitalist Physician (Allopathic & Osteopathic Physicians).
- Where is Ronald Chang located?
- Ronald Chang's practice location on file with NPPES is 1880 N Orange Grove Ave, Pomona, CA 91767-3006.
- What is Ronald Chang's phone number?
- The practice phone number listed in the NPPES registry for Ronald Chang is (909) 630-7158.
- Does Ronald Chang accept Medicare?
- Ronald Chang is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Ronald Chang's NPI active?
- Yes — Ronald Chang's NPI (1861810863) is active in the NPPES registry as of the last update on 2018-10-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.