David Williams, M.D.
David Williams, M.D. is an Ophthalmology Physician in Elizabethtown, PA, registered under NPI 1821176959.
Getting there
The practice address on file is 1676 S MARKET ST, Elizabethtown, PA 17022. 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 |
|---|---|---|
| MD439951 | PA | Ophthalmology Physician primary |
| TRN9942 | FL | Ophthalmology Physician |
| ME103721 | FL | Ophthalmology Physician |
Licences are recorded in 2 states: PA, FL. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Ophthalmology
- PAC ID
- 7416009766
- Enrollment ID
- I20100816000408
Medicare enrolment is recorded as approved under the provider type Practitioner - Ophthalmology. 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.
Licensed in 2 states
This provider holds licences in 2 states: Florida and Pennsylvania. The practice address on file is in Elizabethtown, PA, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- MD439951
- Specialty
- Ophthalmology Physician
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Ophthalmology covers
An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses. NUCC Health Care Provider Taxonomy, code 207W00000X
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 | |
|---|---|---|---|---|
| 207W00000X | Ophthalmology Physician | MD439951 | PA | primary |
| 207W00000X | Ophthalmology Physician | TRN9942 | FL | |
| 207W00000X | Ophthalmology Physician | ME103721 | FL |
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 | 1821176959 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 2, 2006 |
| Last updated | Dec 17, 2024 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
1676 S MARKET ST Elizabethtown, PA 17022 (717) 361-9727 Fax (717) 361-2460 |
| Mailing address |
233 W PENN AVE Cleona, PA 17042 |
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 | 8 | 2 | 1 | 1 | 7 | 6 | 9 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 4 | 1 | 2 | 7 | 3 | 9 | 1 |
Sum = 61 · next multiple of 10 = 70 · check digit = 9 · actual last digit = 9
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.