Larry Mastrogianakis, MD
Larry Mastrogianakis, MD is a Pediatrics Physician in Jacksonville, FL, registered under NPI 1023090800. This provider registers 3 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 12428 SAN JOSE BLVD STE 3, Jacksonville, FL 32223. 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 |
|---|---|---|
| 65705 | GA | Pediatrics Physician primary |
| ME44927 | FL | Specialist |
| 44927 | FL | Hospitalist Physician |
Licences are recorded in 2 states: GA, FL. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Pediatric Medicine
- PAC ID
- 6204158678
Medicare enrolment is recorded as approved under the provider type Practitioner - Pediatric Medicine. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
Licensed in 2 states
This provider holds licences in 2 states: Florida and Georgia. The practice address on file is in Jacksonville, FL, 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 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 Pediatrics covers
A pediatrician is concerned with the physical, emotional and social health of children from birth to young adulthood. Care encompasses a broad spectrum of health services ranging from preventive healthcare to the diagnosis and treatment of acute and chronic diseases. A pediatrician deals with biological, social and environmental influences on the developing child, and with the impact of disease and dysfunction on development. NUCC Health Care Provider Taxonomy, code 208000000X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 208000000X | Pediatrics Physician | 65705 | GA | primary |
| 174400000X | Specialist | ME44927 | FL | |
| 208M00000X | Hospitalist Physician | 44927 | FL |
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 | 1023090800 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 16, 2005 |
| Last updated | Jul 23, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
12428 SAN JOSE BLVD STE 3 Jacksonville, FL 32223 (904) 260-9495 Fax (904) 260-3009 |
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 | 0 | 2 | 3 | 0 | 9 | 0 | 8 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 4 | 3 | 0 | 9 | 0 | 8 | 0 |
Sum = 50 · next multiple of 10 = 50 · check digit = 0 · actual last digit = 0
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.