Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
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Dr. William Thomas O'Connor Jr., MD

Individual provider Family Medicine Physician · NPI 1639127632

Dr. William Thomas O'Connor Jr., MD is a Family Practice in Vacaville, California. Graduated from University of Cincinnati College of Medicine in 1981, 45 years ago. Practices as a sole proprietor, accepts Medicare assignment and offers telehealth. Licensed in California.

Years since qualifying
45
Trained at
University of Cincinnati College of Medicine
Licensed in
CA
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

300 Mason St
Vacaville, CA 95688-4506
Phone: (707) 446-0422
Fax: (707) 446-1655
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Family Medicine Physician (primary) Taxonomy 207Q00000X · Licence G048496 (CA)

Record details

NPI number1639127632
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedMay 4, 2006
Last updated in NPPESDecember 9, 2014

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyFAMILY PRACTICE
Also practisesGENERAL PRACTICE
Medical schoolUNIVERSITY OF CINCINNATI COLLEGE OF MEDICINE
Graduated 1981 (45 years in practice)
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

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