William Mallon
NPI 1558737916 · Clinical Psychologist · Roslindale, MA
William Mallon is a Clinical Psychologist provider in Roslindale, MA (NPI 1558737916).
Provider details
- NPI number
- 1558737916
- Entity type
- Individual
- Primary specialty
- Clinical PsychologistBehavioral Health & Social Service Providers
- Sex
- Male
- Sole proprietor
- No
Specialties & taxonomies
Behavioral Health & Social Service Providers
- Mental Health Counselor101YM0800X
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
10 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
- 2015-08-19
- Last updated
- 2022-07-13
- Certified
- 2022-07-13
Frequently asked questions
- What is William Mallon's NPI number?
- William Mallon's National Provider Identifier (NPI) is 1558737916, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Mallon's specialty?
- William Mallon is listed in the NPPES registry with a primary specialty of Clinical Psychologist (Behavioral Health & Social Service Providers).
- Where is William Mallon located?
- William Mallon's practice location on file with NPPES is 780 American Legion Hwy, Roslindale, MA 02131-3908.
- What is William Mallon's phone number?
- The practice phone number listed in the NPPES registry for William Mallon is (617) 529-9281.
- Is William Mallon's NPI active?
- Yes — William Mallon's NPI (1558737916) is active in the NPPES registry as of the last update on 2022-07-13.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.