Fiachra O'Sullivan, LMFT

NPI 1760785927 · on the registry since 2010 · sole proprietor

Practice

Address: 999 Sutter St
San Francisco, CA 94109
Phone: (415) 967-3447
Organisation at this address: Defina Health
Bay Area Children First
Understanding Behavior Inc.
Inferred from a shared address, not stated in the registry.
Clinicians at this address: 27

Registry record

Primary taxonomy: 106H00000X
106H00000X
Licence states on file: CA
From the registry's licence fields, which are often incomplete.
Sex: Male
Record last updated: 2026-02-08

Source: CMS National Plan and Provider Enumeration System. Registration is not the same as practising, and the registry records no retirement — some people listed here no longer practise. More in California