Gregory Leong, M.D.
Gregory Leong, M.D. is a Forensic Psychiatry Physician in Patton, CA, registered under NPI 1174592158. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 3102 E HIGHLAND AVE, Patton, CA 92369. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| G34482 | CA | Forensic Psychiatry Physician primary |
| MD00025101 | WA | Psychiatry Physician |
| MD00025101 | WA | Forensic Psychiatry Physician |
| G34482 | CA | Psychiatry Physician |
Licences are recorded in 2 states: CA, WA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
Licensed in 2 states
This provider holds licences in 2 states: California and Washington. The practice address on file is in Patton, CA, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- G34482
- Specialty
- Forensic Psychiatry Physician
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Forensic Psychiatry covers
Forensic Psychiatry is a subspecialty with psychiatric focus on interrelationships with civil, criminal and administrative law, evaluation and specialized treatment of individuals involved with the legal system, incarcerated in jails, prisons, and forensic psychiatry hospitals. NUCC Health Care Provider Taxonomy, code 2084F0202X
All registered taxonomy codes
This provider registers 4 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 2084F0202X | Forensic Psychiatry Physician Forensic Psychiatry | G34482 | CA | primary |
| 2084P0800X | Psychiatry Physician Psychiatry | MD00025101 | WA | |
| 2084F0202X | Forensic Psychiatry Physician Forensic Psychiatry | MD00025101 | WA | |
| 2084P0800X | Psychiatry Physician Psychiatry | G34482 | CA |
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1174592158 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 14, 2006 |
| Last updated | Jul 5, 2012 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
3102 E HIGHLAND AVE Patton, CA 92369 (909) 425-6509 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 1 | 7 | 4 | 5 | 9 | 2 | 1 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 5 | 4 | 1 | 9 | 4 | 1 | 1 |
Sum = 52 · next multiple of 10 = 60 · check digit = 8 · actual last digit = 8
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.