IndividualActive
Diana Mah, PSY.D.
NPI 1023321734 · Psychologist · Rialto, CA
Diana Mah, PSY.D. is a Psychologist provider in Rialto, CA (NPI 1023321734).
Provider details
- NPI number
- 1023321734
- Entity type
- Individual
- Primary specialty
- PsychologistBehavioral Health & Social Service Providers
- Credential
- PSY.D.
- Sex
- Female
- Sole proprietor
- Yes
Specialties & taxonomies
Behavioral Health & Social Service Providers
Profile Score
Detailed profile(77/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
15 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
850 E Foothill Blvd
Rialto, CA 92376-5230
Phone: (909) 421-9380
Street-level locationGet directions
Mailing address
303 E Vanderbilt Way
San Bernardino, CA 92415-0026
Registry dates
- Enumerated
- 2010-07-22
- Last updated
- 2019-01-09
Frequently asked questions
- What is Diana Mah's NPI number?
- Diana Mah's National Provider Identifier (NPI) is 1023321734, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Diana Mah's specialty?
- Diana Mah is listed in the NPPES registry with a primary specialty of Psychologist (Behavioral Health & Social Service Providers).
- Where is Diana Mah located?
- Diana Mah's practice location on file with NPPES is 850 E Foothill Blvd, Rialto, CA 92376-5230.
- What is Diana Mah's phone number?
- The practice phone number listed in the NPPES registry for Diana Mah is (909) 421-9380.
- Is Diana Mah's NPI active?
- Yes — Diana Mah's NPI (1023321734) is active in the NPPES registry as of the last update on 2019-01-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.