William Dellefield, M.A., MFT
NPI 1689773061 · Marriage & Family Therapist · Aliso Viejo, CA
William Dellefield, M.A., MFT is a Marriage & Family Therapist provider in Aliso Viejo, CA (NPI 1689773061).
Provider details
- NPI number
- 1689773061
- Entity type
- Individual
- Primary specialty
- Marriage & Family TherapistBehavioral Health & Social Service Providers
- Credential
- M.A., MFT
- Sex
- Male
- Sole proprietor
- No
- License
- MFC 35855 (CA)
Specialties & taxonomies
Behavioral Health & Social Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-09-21
- Last updated
- 2007-07-10
Frequently asked questions
- What is William Dellefield's NPI number?
- William Dellefield's National Provider Identifier (NPI) is 1689773061, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Dellefield's specialty?
- William Dellefield is listed in the NPPES registry with a primary specialty of Marriage & Family Therapist (Behavioral Health & Social Service Providers).
- Where is William Dellefield located?
- William Dellefield's practice location on file with NPPES is 5 Mareblu, Aliso Viejo, CA 92656-3014.
- What is William Dellefield's phone number?
- The practice phone number listed in the NPPES registry for William Dellefield is (949) 643-6930.
- Is William Dellefield's NPI active?
- Yes — William Dellefield's NPI (1689773061) is active in the NPPES registry as of the last update on 2007-07-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.