Warren Johnston, MD
NPI 1427052802 · Cardiovascular Disease Physician · Orange, CA
Enrolled with Medicare as Practitioner - Cardiovascular Disease (cardiology) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Warren Johnston, MD is a Cardiovascular Disease Physician provider in Orange, CA (NPI 1427052802).
Provider details
- NPI number
- 1427052802
- Entity type
- Individual
- Primary specialty
- Cardiovascular Disease PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G33255 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
21 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
1,223 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 Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 574 | $137 |
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report93000 | 120 | $15 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 108 | $98 |
| Ultrasound of Heart With Color-Depicted Blood Flow, Rate, Direction and Valve Function93306 | 88 | $211 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 82 | $177 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 49 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Rosuvastatin Calcium | 1,105 | 387 |
| Metoprolol Succinate | 551 | 184 |
| Amlodipine Besylate | 436 | 137 |
| Apixabanbrand: Eliquis | 359 | 118 |
| Atorvastatin Calcium | 328 | 107 |
| Losartan Potassium | 311 | 97 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$542 across 39 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
- 2005-06-13
- Last updated
- 2021-11-03
- Certified
- 2021-11-03
Frequently asked questions
- What is Warren Johnston's NPI number?
- Warren Johnston's National Provider Identifier (NPI) is 1427052802, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Warren Johnston's specialty?
- Warren Johnston is listed in the NPPES registry with a primary specialty of Cardiovascular Disease Physician (Allopathic & Osteopathic Physicians).
- Where is Warren Johnston located?
- Warren Johnston's practice location on file with NPPES is 1140 W La Veta Ave Ste 430, Orange, CA 92868-4226.
- What is Warren Johnston's phone number?
- The practice phone number listed in the NPPES registry for Warren Johnston is (714) 543-5555.
- Does Warren Johnston accept Medicare?
- Warren Johnston is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Warren Johnston's NPI active?
- Yes — Warren Johnston's NPI (1427052802) is active in the NPPES registry as of the last update on 2021-11-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.