Bret A. Witter, M.D.
Cardiovascular Disease Physician · Los Alamitos, CA
Bret A. Witter, M.D. is a cardiovascular disease physician with a practice address in Los Alamitos, California, and NPI 1396783387, issued on Jun 3, 2006. Check the license (California A45250, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Bret A. Witter
- Credential
- M.D.
- Primary taxonomy
- Cardiovascular Disease Physician 207RC0000X
- License number
- A45250 CA
Self-reported in NPPES; status is on the state search - Practice location
- 5300 Katella Ave, Los Alamitos, CA 90720
- Phone
- (562) 430-7533
- Enumerated
- Jun 3, 2006
- Record last updated
- Oct 11, 2018 (not updated in 8 years: call before relying on the address or phone)
- Fax
- (562) 430-8055
- Medicaid ID
- 00A452500 CA
- Medicare enrollment
- Enrolled (PECOS I20071128000346); accepts Medicare assignment
- Medical or professional school
- Baylor College Of Medicine, 1987
- Entity
- Type 1 · individual
8 nearest cardiovascular disease physician records → All 2,574 in California → Look up another NPI →
Also registered at 5300 Katella Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Carlos ArguedasInternal Medicine Physician1023075579
- Ramandeep Brar, M.D.Cardiovascular Disease Physician1821165549
- Valerie Cacho, MDSleep Medicine (Internal Medicine) Physician1528296845
- Stuart Fischer, M.D.Cardiovascular Disease Physician1083656086
- Steven Forman, M.D.Cardiovascular Disease Physician1023059763
- Diana GlovaciCardiovascular Disease Physician1366805590
Verify Bret A. Witter in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A45250Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
91% more Medicare Part D claims than the average cardiovascular disease physician in 2024
5,889 Medicare Part D claims for 795 beneficiaries, against an average of 3,078 among the 20,728 providers of this specialty who prescribed in Part D. Brand-name drugs were 25% of claims.
Most prescribed
- Eliquis702 claims
- Metoprolol Succinate558 claims
- Amlodipine Besylate400 claims
- Atorvastatin Calcium389 claims
- Xarelto315 claims
- Losartan Potassium271 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.
The MIPS final score for 2023 (Medicare payment program): 88.7 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $212.12
8 payments; by number, the most common kind was food and beverage; the largest payer was Atricure, Inc. 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
- Los Alamitos Internal Medical Group IncLos Alamitos, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Bret A. Witter among 2,574 cardiovascular disease physician records in California
Bret A. Witter, M.D. 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 2006, is newer than 10% of them.
- NPI issued2006 · 10% of these records are older, 45% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated1987 · median 1999 among the 1,742 with a school on file
- Record last updated2018 · 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 Los Alamitos → Cardiovascular Disease Physician nationwide →
The 8 cardiovascular disease physician records with the nearest ZIP codes
- Ramandeep Brar, M.D.Los Alamitos, CA 907201821165549
- Mark Castellanet, M.D.Los Alamitos, CA 907201538165782
- Stuart Fischer, M.D.Los Alamitos, CA 907201083656086
- Steven Forman, M.D.Los Alamitos, CA 907201023059763
- Diana GlovaciLos Alamitos, CA 907201366805590
- Fernando Mendoza, M.D.Los Alamitos, CA 907201063637320
- Timothy O'Neill, M.D.Los Alamitos, CA 907201467493155
- Adrian Shandling, MDLos Alamitos, CA 907201386640522
Common questions
What is Bret A. Witter, M.D.'s NPI number?
Bret A. Witter, M.D.'s National Provider Identifier (NPI) is 1396783387, issued on Jun 3, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Bret A. Witter, M.D. located?
The NPPES record lists a practice address at 5300 Katella Ave, Los Alamitos, CA, 90720. Phone: (562) 430-7533. Providers update this record themselves, so call before visiting.
How can I verify Bret A. Witter, M.D.'s license?
NPPES lists California license number A45250, 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 Bret A. Witter, M.D. prescribe under Medicare Part D?
In 2024, Bret A. Witter, M.D. had 5,889 Medicare Part D claims for 795 beneficiaries; the average among cardiovascular disease physician prescribers was 3,078. Part D covers Medicare prescriptions only.
What is Bret A. Witter, M.D.'s MIPS final score?
The 2023 MIPS final score is 88.7 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.