William Patrick Mazur, M.D.
Infectious Disease Physician · Wilmington, DE
William Patrick Mazur, M.D. is an infectious disease physician with a practice address in Wilmington, Delaware, and NPI 1518250828, issued on May 19, 2011. Check the license (Delaware C1-0008683, as entered in NPPES) on the Delaware Board of Medical Licensure and Discipline; the Medicare figures below come from public CMS files.
- Name
- William Patrick Mazur
- Credential
- M.D.
- Primary taxonomy
- Infectious Disease Physician 207RI0200X
- License number
- C1-0008683 DE
Self-reported in NPPES; status is on the state search - Practice location
- 1400 N Washington St, Wilmington, DE 19801
- Phone
- (302) 320-1300
- Enumerated
- May 19, 2011
- Record last updated
- Nov 4, 2014 (not updated in 12 years: call before relying on the address or phone)
- Fax
- (302) 320-1374
- Medicare enrollment
- Enrolled (PECOS I20111026000289); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest infectious disease physician records → All 32 in Delaware → Look up another NPI →
Also registered at 1400 N Washington St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Karen Antell, MDFamily Medicine Physician1346288230
- Christopher James, PHARM.D.Pharmacist Clinician (PhC)/ Clinical Pharmacy Specialist1376807685
- Sharon MinerPrimary Care Nurse Practitioner1336540657
- Janice Nevin, MDFamily Medicine Physician1487625117
- Lee Preininger, PHARMDPharmacist1477642221
- Susan Szabo, MDInfectious Disease Physician1407834229
Verify William Patrick Mazur in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersDelaware Board of Medical Licensure and Discipline
Search for license C1-0008683Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.2 times the Medicare Part D claims of the average infectious disease physician in 2024
1,519 Medicare Part D claims for 136 beneficiaries, against an average of 689 among the 7,388 providers of this specialty who prescribed in Part D. Brand-name drugs were 68% of claims.
Most prescribed
- Biktarvy352 claims
- Prezcobix96 claims
- Juluca89 claims
- Dovato87 claims
- Triumeq85 claims
- Rosuvastatin Calcium81 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.
Bills Medicare through one group practice
- Christiana Care Health Services IncSmyrna, DE
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Patrick Mazur among 32 infectious disease physician records in Delaware
William Patrick Mazur, M.D. is one of 32 infectious disease physician records with a practice address in Delaware. 91% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2011, is newer than 66% of them.
- NPI issued2011 · 66% of these records are older, 28% newer
- In a Medicare fileYes · 91% of these records are
- In the CMS Doctors and Clinicians fileYes · 88% of these records are
- Graduated1996 · median 2002 among the 28 with a school on file
- Record last updated2014 · 56% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RI0200X and a Delaware practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Infectious Disease Physician providers in Delaware
There are 32 infectious disease physician records in Delaware.
All 32 in Delaware → Every provider in Wilmington → Infectious Disease Physician nationwide →
The 8 infectious disease physician records with the nearest ZIP codes
- Wayne Duffus, M.D.Wilmington, DE 198011174590392
- Robert Jakubowski, M.D.Wilmington, DE 198011043624463
- Deborah Kahal, MD, MPHWilmington, DE 198011821227315
- Susan Szabo, MDWilmington, DE 198011407834229
- Kirsten Hauer, MDWilmington, DE 198051922100023
- Kristen FaccioloNewark, DE 197181487914834
- Shruti Puri, MDNewark, DE 197181003234451
- Alfred Bacon, MDNewark, DE 197131902967508
Common questions
What is William Patrick Mazur, M.D.'s NPI number?
William Patrick Mazur, M.D.'s National Provider Identifier (NPI) is 1518250828, issued on May 19, 2011. An NPI identifies a provider in billing; it is not a license.
Where is William Patrick Mazur, M.D. located?
The NPPES record lists a practice address at 1400 N Washington St, Wilmington, DE, 19801. Phone: (302) 320-1300. Providers update this record themselves, so call before visiting.
How can I verify William Patrick Mazur, M.D.'s license?
NPPES lists Delaware license number C1-0008683, as entered by the provider. Search the Delaware Board of Medical Licensure and Discipline at https://delpros.delaware.gov/OH_VerifyLicense. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William Patrick Mazur, M.D. prescribe under Medicare Part D?
In 2024, William Patrick Mazur, M.D. had 1,519 Medicare Part D claims for 136 beneficiaries; the average among infectious disease physician prescribers was 689. 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.