Mark Douglas Diamond, PHD
Mark Douglas Diamond is a Clinical Psychologist provider (Psychologist) practicing in Temecula, CA, registered in the NPPES registry with NPI 1831247998 since 2007. The credential PHD stands for Doctor of Philosophy.
✓ Active NPI ✓ Valid NPI checksum Sole proprietor
| NPI | 1831247998 |
|---|---|
| Entity type | Individual (Type 1) |
| Name | Mark Douglas Diamond |
| Credential | PHD |
| Sex | Male |
| Practice address | Temecula, CA, 92591 |
| Phone | 9516932486 |
| Enumeration date | 2007-01-08 |
| Last updated in NPPES | 2007-07-08 |
Street address withheld — NPPES sole-proprietor addresses can be home addresses. See our data policy.
Taxonomy & licenses
| Taxonomy code | Specialty | Primary | License | State |
|---|---|---|---|---|
| 103TC0700X | Clinical Psychologist | Primary | PSY8771 | CA |
PHD — Doctor of Philosophy: A doctoral degree; in healthcare often held by clinical psychologists and researchers. About the PHD credential
Other identifiers
| Identifier | Type | State | Issuer |
|---|---|---|---|
| PJ0087710 | Other | CA | MEDICAL |
Copy-ready billing details
Provider: Mark Diamond, PHD NPI: 1831247998 Taxonomy: 103TC0700X (Clinical Psychologist) Address: Temecula, CA, 92591
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Verify this record
Cross-check NPI 1831247998 against the authoritative CMS record: view Mark Douglas Diamond on the official NPPES registry .
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes — even if the provider moves or changes specialty. Read the full guide or validate an NPI number.
Frequently asked questions
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Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2007-07-08.