Mary Gercke, CRNP
Mary Gercke, CRNP is an Adult Health Nurse Practitioner in Baltimore, MD, registered under NPI 1528408895. This provider registers 3 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 323 N CALVERT ST, Baltimore, MD 21202. 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 |
|---|---|---|
| R065950 | MD | Adult Health Nurse Practitioner primary |
| R065950 | MD | Primary Care Nurse Practitioner |
| R065950 | MD | Gerontology Clinical Nurse Specialist |
This provider holds licence R065950 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 Adult Health covers
Definition to come... NUCC Health Care Provider Taxonomy, code 363LA2200X
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 | |
|---|---|---|---|---|
| 363LA2200X | Adult Health Nurse Practitioner Adult Health | R065950 | MD | primary |
| 363LP2300X | Primary Care Nurse Practitioner Primary Care | R065950 | MD | |
| 364SG0600X | Gerontology Clinical Nurse Specialist Gerontology | R065950 | MD |
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 | 1528408895 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 1, 2013 |
| Last updated | Jul 15, 2013 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Credential | CRNP |
| Practice address |
323 N CALVERT ST Baltimore, MD 21202 (410) 332-9083 |
| Mailing address |
1402 MARYWOOD DR Bel Air, MD 21014 |
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 | 2 | 8 | 4 | 0 | 8 | 8 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 4 | 8 | 8 | 0 | 7 | 8 | 9 |
Sum = 75 · next multiple of 10 = 80 · check digit = 5 · actual last digit = 5
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.