Mark Willoughby
NPI 1174038756 · Addiction (Substance Use Disorder) Counselor · El Monte, CA
Mark Willoughby is a Addiction (Substance Use Disorder) Counselor provider in El Monte, CA (NPI 1174038756).
Provider details
- NPI number
- 1174038756
- Entity type
- Individual
- Primary specialty
- Addiction (Substance Use Disorder) CounselorBehavioral Health & Social Service Providers
- Sex
- Male
- Sole proprietor
- No
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
8 yrs in NPPES registry
- Profile completeness38% of score
83% 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
- 2017-12-05
- Last updated
- 2017-12-05
Frequently asked questions
- What is Mark Willoughby's NPI number?
- Mark Willoughby's National Provider Identifier (NPI) is 1174038756, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Willoughby's specialty?
- Mark Willoughby is listed in the NPPES registry with a primary specialty of Addiction (Substance Use Disorder) Counselor (Behavioral Health & Social Service Providers).
- Where is Mark Willoughby located?
- Mark Willoughby's practice location on file with NPPES is 3430 Cogswell Rd, El Monte, CA 91732-2785.
- What is Mark Willoughby's phone number?
- The practice phone number listed in the NPPES registry for Mark Willoughby is (626) 453-3400.
- Is Mark Willoughby's NPI active?
- Yes — Mark Willoughby's NPI (1174038756) is active in the NPPES registry as of the last update on 2017-12-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.