John Matthews, MD
John Matthews, MD is an Addiction Psychiatry Physician in Boston, MA, registered under NPI 1386627164. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 55 FRUIT ST WRN 12, 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 |
|---|---|---|
| 50815 | MA | Psychiatry Physician |
| 50815 | MA | Addiction Psychiatry Physician primary |
This provider holds licence 50815 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
- 7517942964
- Enrollment ID
- I20040621001298
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 Addiction Psychiatry covers
Addiction Psychiatry is a subspecialty of psychiatry that focuses on evaluation and treatment of individuals with alcohol, drug, or other substance-related disorders, and of individuals with dual diagnosis of substance-related and other psychiatric disorders. NUCC Health Care Provider Taxonomy, code 2084P0802X
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 | |
|---|---|---|---|---|
| 2084P0800X | Psychiatry Physician Psychiatry | 50815 | MA | |
| 2084P0802X | Addiction Psychiatry Physician Addiction Psychiatry | 50815 | MA | primary |
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 | 1386627164 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 25, 2005 |
| Last updated | Jul 13, 2026 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | MD |
| Practice address |
55 FRUIT ST WRN 12 Boston, MA 02114 (617) 724-9144 Fax (617) 724-9155 |
| Mailing address |
PO BOX 9142 MASS. GENERAL PHYSICIAN ORGANIZATION Charlestown, MA 02129 |
| Other identifiers |
3004066
· Medicaid (MA) 735411 · Other (MA) J03365 · 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 | 8 | 6 | 6 | 2 | 7 | 1 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 3 | 7 | 6 | 3 | 2 | 5 | 1 | 3 |
Sum = 56 · next multiple of 10 = 60 · check digit = 4 · actual last digit = 4
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.