Warren David Johnston, MD
Cardiovascular Disease Physician · Orange, CA
Warren David Johnston, MD is a cardiovascular disease physician with a practice address in Orange, California, and NPI 1427052802, issued on Jun 13, 2005. Check the license (California G33255, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Warren David Johnston
- Credential
- MD
- Primary taxonomy
- Cardiovascular Disease Physician 207RC0000X
- License number
- G33255 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1140 W LA Veta Ave Ste 430, Orange, CA 92868
- Phone
- (714) 543-5555
- Enumerated
- Jun 13, 2005
- Record last updated
- Nov 3, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (714) 836-2427
- Medicaid ID
- 00G332550 CA
- Medicare enrollment
- Enrolled (PECOS I20080301000100); accepts Medicare assignment
- Medical or professional school
- University Of Rochester School Of Medicine And Dentistry, 1975
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest cardiovascular disease physician records → All 2,574 in California → Look up another NPI →
Also registered at 1140 W LA Veta Ave Ste 430
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Erum Bajwa, M.D,Cardiovascular Disease Physician1184069239
- Michael Chan, M.D.Interventional Cardiology Physician1487660833
- Lauren Daggett, PA-CPhysician Assistant1801525621
- Aileen Jiras, PAMedical Physician Assistant1063054641
- Thomas Kim, M.D.Specialist1144225301
- Danny Lee, M.D.Clinical Cardiac Electrophysiology Physician1740568427
Verify Warren David Johnston in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G33255Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
79% more Medicare Part D claims than the average cardiovascular disease physician in 2024
5,505 Medicare Part D claims for 897 beneficiaries, against an average of 3,078 among the 20,728 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims.
Most prescribed
- Rosuvastatin Calcium1,105 claims
- Metoprolol Succinate551 claims
- Amlodipine Besylate436 claims
- Eliquis359 claims
- Atorvastatin Calcium328 claims
- Losartan Potassium311 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $542.28
39 payments; by number, the most common kind was food and beverage; the largest payer was Novartis Pharmaceuticals Corporation. The 16,686 providers of this specialty with any payment received $3,819.56 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Providence Medical FoundationOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Warren David Johnston among 2,574 cardiovascular disease physician records in California
Warren David Johnston, MD is one of 2,574 cardiovascular disease physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 90% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated1975 · median 1999 among the 1,742 with a school on file
- Record last updated2021 · 63% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RC0000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Cardiovascular Disease Physician providers in California
There are 2,574 cardiovascular disease physician records in California.
All 2,574 in California → Every provider in Orange → Cardiovascular Disease Physician nationwide →
The 8 cardiovascular disease physician records with the nearest ZIP codes
- Hossein Alimadadian, M.D.Orange, CA 928681285664029
- Dicran Baron, MDOrange, CA 928681881689347
- Michael Dam, MDOrange, CA 928681376547000
- Irmina Gradus-Pizlo, M.D.Orange, CA 928681356305254
- Morton Kern, MDOrange, CA 928681770587131
- Jessica Li, M.D.Orange, CA 928681982638649
- Donald Mahon, M.D.Orange, CA 928681255335659
- Joseph Ruggio, MDOrange, CA 928681124023163
Common questions
What is Warren David Johnston, MD's NPI number?
Warren David Johnston, MD's National Provider Identifier (NPI) is 1427052802, issued on Jun 13, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Warren David Johnston, MD located?
The NPPES record lists a practice address at 1140 W LA Veta Ave Ste 430, Orange, CA, 92868. Phone: (714) 543-5555. Providers update this record themselves, so call before visiting.
How can I verify Warren David Johnston, MD's license?
NPPES lists California license number G33255, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Warren David Johnston, MD prescribe under Medicare Part D?
In 2024, Warren David Johnston, MD had 5,505 Medicare Part D claims for 897 beneficiaries; the average among cardiovascular disease physician prescribers was 3,078. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.