Ronald Sierzenski, M.D.
Ronald Sierzenski, M.D. is an Emergency Medicine Physician in Chandler, AZ, registered under NPI 1861428633. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 475 S DOBSON RD, Chandler, AZ 85224. 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 |
|---|---|---|
| 28468 | AZ | Emergency Medicine Physician primary |
| 28468 | AZ | Emergency Medical Services (Emergency… |
| 28468 | AZ | Undersea and Hyperbaric Medicine… |
This provider holds licence 28468 issued in AZ. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Emergency Medicine
- PAC ID
- 6901893619
- Enrollment ID
- I20040426001706
Medicare enrolment is recorded as approved under the provider type Practitioner - Emergency Medicine. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Emergency Medicine covers
An emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospital setting by directing emergency medical technicians and in the emergency department. The emergency physician provides immediate recognition, evaluation, care, stabilization and disposition of a generally diversified population of adult and pediatric patients in response to acute illness and injury. NUCC Health Care Provider Taxonomy, code 207P00000X
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 | |
|---|---|---|---|---|
| 207P00000X | Emergency Medicine Physician | 28468 | AZ | primary |
| 207PE0004X | Emergency Medical Services (Emergency Medicine) Physician Emergency Medical Services | 28468 | AZ | |
| 207PE0005X | Undersea and Hyperbaric Medicine (Emergency Medicine) Physician Undersea and Hyperbaric Medicine | 28468 | AZ |
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 | 1861428633 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 24, 2006 |
| Last updated | Apr 22, 2010 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
475 S DOBSON RD Chandler, AZ 85224 (480) 963-4561 |
| Mailing address |
1539 E TULSA ST Gilbert, AZ 85296 |
| Other identifiers |
537003
· Medicaid (AZ) AZ0736120 · Other (AZ) |
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 | 4 | 2 | 8 | 6 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 3 | 1 | 8 | 2 | 7 | 6 | 6 |
Sum = 67 · next multiple of 10 = 70 · check digit = 3 · actual last digit = 3
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.