Christopher Johnston, DO
Christopher Johnston, DO is a Critical Care Medicine (Internal Medicine) Physician in Philadelphia, PA, registered under NPI 1548589948. This provider registers 4 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 3998 RED LION RD STE 213, Philadelphia, PA 19114. 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 |
|---|---|---|
| OS017185 | PA | Critical Care Medicine (Internal… primary |
| OS017185 | PA | Neurocritical Care Physician |
| OS017185 | PA | Neurology Physician |
This provider holds licence OS017185 issued in PA. 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 - Neurology
- PAC ID
- 4082907233
Enrolled in Medicare 9 times, across 9 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Pennsylvania | I20160726000147 | Practitioner - Neurology |
| Iowa | I20251224001499 | Practitioner - Neurology |
| Louisiana | I20251230003455 | Practitioner - Neurology |
| Oklahoma | I20251230003552 | Practitioner - Neurology |
| Minnesota | I20251231003377 | Practitioner - Neurology |
| Alabama | I20260102000041 | Practitioner - Neurology |
| Kansas | I20260127001690 | Practitioner - Neurology |
| Wisconsin | I20260211004009 | Practitioner - Neurology |
| South Dakota | I20260223003047 | Practitioner - Neurology |
Medicare enrolment is recorded as approved under the provider type Practitioner - Neurology. There are 9 separate enrolment records across 9 states (PA, IA, LA, OK, MN, AL, KS, WI, SD). Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. 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 Critical Care Medicine covers
An internist who diagnoses, treats and supports patients with multiple organ dysfunction. This specialist may have administrative responsibilities for intensive care units and may also facilitate and coordinate patient care among the primary physician, the critical care staff and other specialists. NUCC Health Care Provider Taxonomy, code 207RC0200X
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 | |
|---|---|---|---|---|
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | OS017185 | PA | primary |
| 2084A2900X | Neurocritical Care Physician Neurocritical Care | OS017185 | PA | |
| 2084N0400X | Neurology Physician Neurology | OS017185 | PA | |
| 390200000X | Student in an Organized Health Care Education/Training Program | — | — |
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 | 1548589948 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 25, 2010 |
| Last updated | Jun 29, 2022 |
| Status | Active |
| Sole proprietor | No |
| Credential | DO |
| Practice address |
3998 RED LION RD STE 213 Philadelphia, PA 19114 (215) 938-7730 |
| Mailing address |
3501 MASONS MILL RD STE 503 Huntingdon Valley, PA 19006 |
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 | 5 | 4 | 8 | 5 | 8 | 9 | 9 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 8 | 8 | 1 | 8 | 9 | 9 | 8 |
Sum = 82 · next multiple of 10 = 90 · 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.