Bryan Dieffenbach, M.D.
Vascular Surgery Physician · San Diego, CA
Bryan Dieffenbach, M.D. is a vascular surgery physician with a practice address in San Diego, California, and NPI 1326466137, issued on Mar 31, 2014. Check the license (California A188066, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Bryan Dieffenbach
- Credential
- M.D.
- Primary taxonomy
- Vascular Surgery Physician 2086S0129X
- License number
- A188066 CA
Self-reported in NPPES; status is on the state search - Practice location
- 550 Washington St Ste 641, San Diego, CA 92103
- Phone
- (619) 299-2600
- Enumerated
- Mar 31, 2014
- Record last updated
- May 14, 2025
- Fax
- (619) 299-3923
- Medicare enrollment
- Enrolled (PECOS I20230919002984); accepts Medicare assignment
- Medical or professional school
- University Of California, San Diego School Of Medicine, 2014
- Entity
- Type 1 · individual
8 nearest vascular surgery physician records → All 580 in California → Look up another NPI →
Also registered at 550 Washington St Ste 641
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Vishal Bansal, M.D.Trauma Surgery Physician1194889410
- Richard Blum, M.D.Cardiovascular Disease Physician1043310030
- Michael Krzyzaniak, M.D.Trauma Surgery Physician1164626594
- Kimberly Peck, MDSurgery Physician1215018403
- Fakhri Salem, M.D.Specialist1659416485
- Amelia Simpson, M.D.Trauma Surgery Physician1538484084
Verify Bryan Dieffenbach in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A188066Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
64% fewer Medicare Part D claims than the average vascular surgery physician in 2024
72 Medicare Part D claims for 30 beneficiaries, against an average of 201 among the 3,936 providers of this specialty who prescribed in Part D. 17 claims were for opioids.
Most prescribed
- Cilostazol17 claims
- Clopidogrel14 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: $1,464.12
18 payments; by number, the most common kind was food and beverage; the largest payer was Endologix LLC. The 4,059 providers of this specialty with any payment received $6,178.00 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 2 group practices
- ON Call Specialists Medical Group OF San Diego IncSan Diego, CA
- Regents OF The University OF CaliforniaSan Diego, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Bryan Dieffenbach among 580 vascular surgery physician records in California
Bryan Dieffenbach, M.D. is one of 580 vascular surgery physician records with a practice address in California. 84% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2014, is newer than 82% of them.
- NPI issued2014 · 82% of these records are older, 16% newer
- In a Medicare fileYes · 84% of these records are
- In the CMS Doctors and Clinicians fileYes · 71% of these records are
- Graduated2014 · median 2003 among the 411 with a school on file
- Record last updated2025 · 53% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2086S0129X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Vascular Surgery Physician providers in California
There are 580 vascular surgery physician records in California.
All 580 in California → Every provider in San Diego → Vascular Surgery Physician nationwide →
The 8 vascular surgery physician records with the nearest ZIP codes
- Warner Bundens, M.D.San Diego, CA 921031336179027
- Sadia Ilyas, M.D.San Diego, CA 921031699093807
- John Lane, MDSan Diego, CA 921031043390172
- Erik Owens, MDSan Diego, CA 921031578506523
- Elsie Ross, MDSan Diego, CA 921031316237548
- Steven Shackford, M.D.San Diego, CA 921031144244419
- Michael Sise, M.D.San Diego, CA 921031487617627
- Jeffrey Weiss, MDSan Diego, CA 921031699833012
Common questions
What is Bryan Dieffenbach, M.D.'s NPI number?
Bryan Dieffenbach, M.D.'s National Provider Identifier (NPI) is 1326466137, issued on Mar 31, 2014. An NPI identifies a provider in billing; it is not a license.
Where is Bryan Dieffenbach, M.D. located?
The NPPES record lists a practice address at 550 Washington St Ste 641, San Diego, CA, 92103. Phone: (619) 299-2600. Providers update this record themselves, so call before visiting.
How can I verify Bryan Dieffenbach, M.D.'s license?
NPPES lists California license number A188066, 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 Bryan Dieffenbach, M.D. prescribe under Medicare Part D?
In 2024, Bryan Dieffenbach, M.D. had 72 Medicare Part D claims for 30 beneficiaries; the average among vascular surgery physician prescribers was 201. 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.