Deborah Blacker, MD SCD
Deborah Blacker, MD SCD is a Geriatric Psychiatry Physician in Boston, MA, registered under NPI 1205800521. This provider registers 2 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 55 FRUIT ST 149 2691 MASSACHUSETTS GENERAL HOSPITAL, Boston, MA 02114. 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 |
|---|---|---|
| 55900 | MA | Geriatric Psychiatry Physician primary |
| 55900 | MA | Psychiatry Physician |
This provider holds licence 55900 issued in MA. 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 - Geriatric Psychiatry
- PAC ID
- 9335185990
- Enrollment ID
- I20050705000828
Medicare enrolment is recorded as approved under the provider type Practitioner - Geriatric Psychiatry. 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 Geriatric Psychiatry covers
Geriatric Psychiatry is a subspecialty with psychiatric expertise in prevention, evaluation, diagnosis and treatment of mental and emotional disorders in the elderly, and improvement of psychiatric care for healthy and ill elderly patients. NUCC Health Care Provider Taxonomy, code 2084P0805X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 2084P0805X | Geriatric Psychiatry Physician Geriatric Psychiatry | 55900 | MA | primary |
| 2084P0800X | Psychiatry Physician Psychiatry | 55900 | MA |
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 | 1205800521 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Feb 14, 2006 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD SCD |
| Practice address |
55 FRUIT ST 149 2691 MASSACHUSETTS GENERAL HOSPITAL Boston, MA 02114 (617) 726-5571 Fax (617) 726-5760 |
| Mailing address |
PO BOX 9142 MASS GENERAL PHYSICIAN ORGANIZATION Charlestown, MA 02129 |
| Other identifiers |
3032663
· Medicaid (MA) J08006 · Other |
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 | 2 | 0 | 5 | 8 | 0 | 0 | 5 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 0 | 5 | 7 | 0 | 0 | 5 | 4 |
Sum = 49 · next multiple of 10 = 50 · check digit = 1 · actual last digit = 1
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.