Mark Massak, D.O.
Mark Massak, D.O. is a Vascular & Interventional Radiology Physician in Chambersburg, PA, registered under NPI 1952740532.
Getting there
The practice address on file is 12 ST. PAUL DRIVE WELLSPAN RADIOLOGY, Chambersburg, PA 17201. 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 |
|---|---|---|
| OS020464 | PA | Vascular & Interventional Radiology… primary |
This provider holds licence OS020464 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 - Interventional Radiology
- PAC ID
- 3375847361
- Enrollment ID
- I20200611000924
Medicare enrolment is recorded as approved under the provider type Practitioner - Interventional Radiology. 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 Vascular & Interventional Radiology covers
A radiologist who diagnoses and treats diseases by various radiologic imaging modalities. These include fluoroscopy, digital radiography, computed tomography, sonography and magnetic resonance imaging. NUCC Health Care Provider Taxonomy, code 2085R0204X
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 | 1952740532 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 18, 2013 |
| Last updated | Feb 2, 2026 |
| Status | Active |
| Sole proprietor | No |
| Credential | D.O. |
| Practice address |
12 ST. PAUL DRIVE WELLSPAN RADIOLOGY Chambersburg, PA 17201 (717) 217-6026 |
| Mailing address |
601 MEMORY LN York, PA 17402 |
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 | 9 | 5 | 2 | 7 | 4 | 0 | 5 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 9 | 1 | 2 | 5 | 4 | 0 | 5 | 6 |
Sum = 58 · next multiple of 10 = 60 · check digit = 2 · actual last digit = 2
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.