Jeffrey Friedman, M.D.
Jeffrey Friedman, M.D. is a Geriatric Psychiatry Physician in Cambridge, MA, registered under NPI 1356308126. 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 875 MASSACHUSETTS AVE SUITE 51, Cambridge, MA 02139. 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 |
|---|---|---|
| 51517 | MA | Geriatric Psychiatry Physician primary |
| 51517 | MA | Forensic Psychiatry Physician |
| 51517 | MA | Psychiatry Physician |
This provider holds licence 51517 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 - Psychiatry
- PAC ID
- 8224084199
- Enrollment ID
- I20050323001042
Medicare enrolment is recorded as approved under the provider type Practitioner - 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 3 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 | 51517 | MA | primary |
| 2084F0202X | Forensic Psychiatry Physician Forensic Psychiatry | 51517 | MA | |
| 2084P0800X | Psychiatry Physician Psychiatry | 51517 | 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 | 1356308126 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 27, 2006 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
875 MASSACHUSETTS AVE SUITE 51 Cambridge, MA 02139 (617) 864-5560 Fax (617) 864-5560 |
| Other identifiers |
J02871
· Other (MA) |
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 | 3 | 5 | 6 | 3 | 0 | 8 | 1 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 3 | 1 | 6 | 6 | 0 | 7 | 1 | 4 |
Sum = 54 · next multiple of 10 = 60 · check digit = 6 · actual last digit = 6
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.