Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
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Dr. Timmothy O Merrigan, MD

Individual provider Family Medicine Physician · NPI 1063442945

Dr. Timmothy O Merrigan, MD is a Family Practice in Walnut Creek, California. Graduated from Medical College of Wisconsin in 1995, 31 years ago. Practices with Permanente Medical Group Inc, a 10,941-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
31
Trained at
Medical College of Wisconsin
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

320 Lennon Ln
Walnut Creek, CA 94598-2419
Phone: (924) 906-2326
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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 A63055 (CA)

Record details

NPI number1063442945
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedJuly 4, 2006
Last updated in NPPESFebruary 11, 2022

Medicare enrollment

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

Medicare specialtyFAMILY PRACTICE
Medical schoolMEDICAL COLLEGE OF WISCONSIN
Graduated 1995 (31 years in practice)
Group practice Permanente Medical Group Inc — 10941 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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