William Cohen, M.D.
William Cohen, M.D. is a Child & Adolescent Psychiatry Physician in Washington, DC, registered under NPI 1477865046. 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 3800 RESERVOIR RD NW, Washington, DC 20007. 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 |
|---|---|---|
| MD042426 | DC | Child & Adolescent Psychiatry Physician primary |
This provider holds licence MD042426 issued in DC. 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
- 6709172059
- Enrollment ID
- I20160913000489
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 Child & Adolescent Psychiatry covers
Child & Adolescent Psychiatry is a subspecialty of psychiatry with additional skills and training in the diagnosis and treatment of developmental, behavioral, emotional, and mental disorders of childhood and adolescence. NUCC Health Care Provider Taxonomy, code 2084P0804X
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 | 1477865046 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 11, 2010 |
| Last updated | Mar 16, 2017 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
3800 RESERVOIR RD NW Washington, DC 20007 (202) 944-5400 |
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 | 4 | 7 | 7 | 8 | 6 | 5 | 0 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 5 | 7 | 7 | 6 | 1 | 0 | 8 |
Sum = 64 · next multiple of 10 = 70 · 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.