Christopher O'brien, M.D.
Christopher O'brien, M.D. is a Pediatric Ophthalmology and Strabismus Specialist Physician in Knoxville, TN, registered under NPI 1629263421. 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 6311 KINGSTON PIKE SUITE 6W, Knoxville, TN 37919. 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 |
|---|---|---|
| MD-49470 | TN | Ophthalmology Physician |
| A116707 | CA | Ophthalmology Physician |
| MD-49470 | TN | Pediatric Ophthalmology and Strabismus… primary |
Licences are recorded in 2 states: TN, CA. 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
- 9537337555
Enrolled in Medicare 3 times, across 3 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Tennessee | I20150112002307 | Practitioner - Ophthalmology |
| New York | I20200409000531 | Practitioner - Ophthalmology |
| Mississippi | I20250830000737 | Practitioner - Ophthalmology |
Medicare enrolment is recorded as approved under the provider type Practitioner - Ophthalmology. There are 3 separate enrolment records across 3 states (TN, NY, MS). Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. 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: California and Tennessee. The practice address on file is in Knoxville, TN, 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
- MD-49470
- 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 Pediatric Ophthalmology and Strabismus Specialist covers
An ophthalmologist who specializes in pediatric ophthalmology and strabismus management. The subspecialty includes the medical and surgical management of eye disorders found in children. Some of the more common disorders include amblyopia, strabismus, refractive error, cataract and glaucoma. These disorders may be related to neurological and endocrinological diseases, trauma, or aging changes in the extraocular muscles requiring medical, optical and surgical management. NUCC Health Care Provider Taxonomy, code 207WX0110X
All registered taxonomy codes
This provider registers 4 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207W00000X | Ophthalmology Physician | MD-49470 | TN | |
| 207W00000X | Ophthalmology Physician | A116707 | CA | |
| 390200000X | Student in an Organized Health Care Education/Training Program | — | — | |
| 207WX0110X | Pediatric Ophthalmology and Strabismus Specialist Physician Pediatric Ophthalmology and Strabismus Specialist | MD-49470 | TN | 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 | 1629263421 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 14, 2007 |
| Last updated | Apr 18, 2020 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | M.D. |
| Practice address |
6311 KINGSTON PIKE SUITE 6W Knoxville, TN 37919 (865) 262-8473 Fax (865) 262-8550 |
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 | 6 | 2 | 9 | 2 | 6 | 3 | 4 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 4 | 9 | 4 | 6 | 6 | 4 | 4 |
Sum = 69 · next multiple of 10 = 70 · check digit = 1 · actual last digit = 1
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.