Karen Weiss, MD
Karen Weiss, MD is a Pediatric Hematology & Oncology Physician in Hatfield, PA, registered under NPI 1043790967. 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 733 CHURCH RD, Hatfield, PA 19440. 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 |
|---|---|---|
| D34387 | MD | Pediatric Hematology & Oncology Physician primary |
This provider holds licence D34387 issued in MD. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Pediatric Hematology-Oncology covers
A pediatrician trained in the combination of pediatrics, hematology and oncology to recognize and manage pediatric blood disorders and cancerous diseases. NUCC Health Care Provider Taxonomy, code 2080P0207X
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 | 1043790967 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Aug 20, 2018 |
| Last updated | Aug 20, 2018 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
733 CHURCH RD Hatfield, PA 19440 (240) 271-0350 |
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 | 4 | 3 | 7 | 9 | 0 | 9 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 8 | 3 | 5 | 9 | 0 | 9 | 3 |
Sum = 63 · next multiple of 10 = 70 · check digit = 7 · actual last digit = 7
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.