William Gross, M.D.
William Gross, M.D. is an Addiction Psychiatry Physician in Brooklyn, NY, registered under NPI 1982665907. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 591 KINGSTON AVE KINGS COUNTY HOSP., Brooklyn, NY 11203. 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 |
|---|---|---|
| 169896-1 | NY | Addiction Psychiatry Physician primary |
| 169896-1 | NY | Addiction Medicine (Psychiatry &… |
| 169896-1 | NY | Psychiatry Physician |
This provider holds licence 169896-1 issued in NY. 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 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 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 2084P0802X | Addiction Psychiatry Physician Addiction Psychiatry | 169896-1 | NY | primary |
| 2084A0401X | Addiction Medicine (Psychiatry & Neurology) Physician Addiction Medicine | 169896-1 | NY | |
| 2084P0800X | Psychiatry Physician Psychiatry | 169896-1 | NY |
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 | 1982665907 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 29, 2006 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
591 KINGSTON AVE KINGS COUNTY HOSP. Brooklyn, NY 11203 (718) 245-4871 Fax (718) 245-4890 |
| Mailing address |
225 LINCOLN PL Brooklyn, NY 11217 |
| Other identifiers |
00246117
· Medicaid (NY) 186BNI · Other (NY) |
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 | 9 | 8 | 2 | 6 | 6 | 5 | 9 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 9 | 7 | 2 | 3 | 6 | 1 | 9 | 0 |
Sum = 63 · next multiple of 10 = 70 · check digit = 7 · actual last digit = 7
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.