Iwan Ong, MD
NPI 1265416739 · Internal Medicine Physician · Riverside, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Iwan Ong, MD is a Internal Medicine Physician provider in Riverside, CA (NPI 1265416739).
Provider details
- NPI number
- 1265416739
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G69360 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 50 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 306 | 199 |
| Omeprazole | 95 | 61 |
| Levothyroxine Sodium | 69 | 43 |
| Alendronate Sodium | 53 | 29 |
| Pantoprazole Sodium | 50 | 32 |
| Meloxicam | 47 | 43 |
| Amlodipine Besylate | 44 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-11-30
- Last updated
- 2021-12-01
Frequently asked questions
- What is Iwan Ong's NPI number?
- Iwan Ong's National Provider Identifier (NPI) is 1265416739, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Iwan Ong's specialty?
- Iwan Ong is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Iwan Ong located?
- Iwan Ong's practice location on file with NPPES is 10800 Magnolia Ave, Riverside, CA 92505-3043.
- What is Iwan Ong's phone number?
- The practice phone number listed in the NPPES registry for Iwan Ong is (866) 984-7483.
- Does Iwan Ong accept Medicare?
- Iwan Ong is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Iwan Ong's NPI active?
- Yes — Iwan Ong's NPI (1265416739) is active in the NPPES registry as of the last update on 2021-12-01.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.