Jonathan Ou, M.D
NPI 1518109719 · Internal Medicine Physician · Diamond Bar, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Jonathan Ou, M.D is a Internal Medicine Physician provider in Diamond Bar, CA (NPI 1518109719).
Provider details
- NPI number
- 1518109719
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D
- Sex
- Male
- Sole proprietor
- No
- License
- A113176 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
17 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
426 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 177 | $97 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 115 | $138 |
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report93000 | 60 | $15 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 32 | $136 |
| Administration of Influenza Virus VaccineG0008 | 31 | $35 |
| Administration of Pneumococcal VaccineG0009 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 71 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 500 | 153 |
| Metformin Hcl | 310 | 90 |
| Losartan Potassium | 281 | 79 |
| Amlodipine Besylate | 246 | 73 |
| Lisinopril | 236 | 68 |
| Levothyroxine Sodium | 159 | 41 |
| Simvastatin | 144 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$25 across 1 record (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)
- 2251 N Harbor BlvdFullerton, CA 92835-2601Phone: (714) 449-6230
Registry dates
- Enumerated
- 2009-04-02
- Last updated
- 2018-08-20
Frequently asked questions
- What is Jonathan Ou's NPI number?
- Jonathan Ou's National Provider Identifier (NPI) is 1518109719, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Jonathan Ou's specialty?
- Jonathan Ou is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Jonathan Ou located?
- Jonathan Ou's practice location on file with NPPES is 2707 S Diamond Bar Blvd Ste 104, Diamond Bar, CA 91765.
- What is Jonathan Ou's phone number?
- The practice phone number listed in the NPPES registry for Jonathan Ou is (909) 594-8331.
- Does Jonathan Ou accept Medicare?
- Jonathan Ou is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Jonathan Ou's NPI active?
- Yes — Jonathan Ou's NPI (1518109719) is active in the NPPES registry as of the last update on 2018-08-20.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.