William Clark, M.D.
William Clark, M.D. is a Geriatric Psychiatry Physician in Laurel, MS, registered under NPI 1518987478. 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 1603 OLD AMY RD, Laurel, MS 39440. 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 |
|---|---|---|
| 15708 | MS | Geriatric Psychiatry Physician primary |
This provider holds licence 15708 issued in MS. 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 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
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 | 1518987478 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 20, 2006 |
| Last updated | Jul 8, 2013 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Male |
| Credential | M.D. |
| Practice address |
1603 OLD AMY RD Laurel, MS 39440 (601) 428-7100 Fax (601) 428-7159 |
| Other identifiers |
00118813
· Medicaid (MS) |
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 | 5 | 1 | 8 | 9 | 8 | 7 | 4 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 2 | 8 | 9 | 8 | 5 | 4 | 5 |
Sum = 72 · next multiple of 10 = 80 · check digit = 8 · actual last digit = 8
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.