Mary Gessner-peterson, DO
Mary Gessner-peterson, DO is an Emergency Medical Services (Emergency Medicine) Physician in Alpine, CA, registered under NPI 1861662884. 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 2710 ALPINE BLVD # 205, Alpine, CA 91901. 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 |
|---|---|---|
| OS014103 | PA | Emergency Medical Services (Emergency… primary |
| 20A1174 | CA | Internal Medicine Physician |
Licences are recorded in 2 states: PA, CA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Internal Medicine
- PAC ID
- 9638200033
Medicare enrolment is recorded as approved under the provider type Practitioner - Internal 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: California and Pennsylvania. The practice address on file is in Alpine, 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
- 20A1174
- Specialty
- Internal Medicine Physician
- Licence
- OS014103
- Specialty
- Emergency Medical Services (Emergency…
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 Emergency Medical Services covers
An emergency medicine physician who specializes in non-hospital based emergency medical services (e.g., disaster site, accident scene, transport vehicle, etc.) to provide pre-hospital assessment, treatment, and transport patients. NUCC Health Care Provider Taxonomy, code 207PE0004X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207PE0004X | Emergency Medical Services (Emergency Medicine) Physician Emergency Medical Services | OS014103 | PA | primary |
| 207R00000X | Internal Medicine Physician | 20A1174 | 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 | 1861662884 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 5, 2008 |
| Last updated | Sep 26, 2018 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | DO |
| Practice address |
2710 ALPINE BLVD # 205 Alpine, CA 91901 (619) 326-4445 |
| Mailing address |
2710 ALPINE BLVD Alpine, CA 91901 |
| Other identifiers |
825521721
· URGENT CARE TAX ID (CA) |
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 | 8 | 6 | 1 | 6 | 6 | 2 | 8 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 3 | 1 | 3 | 6 | 4 | 8 | 7 |
Sum = 66 · next multiple of 10 = 70 · check digit = 4 · actual last digit = 4
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.