Mark Benjamin, OPTOMETRIST OD DEGRE
Mark Benjamin, OPTOMETRIST OD DEGRE is a provider specialising in Vision Therapy Optometrist in Merrillville, IN, registered under NPI 1669599403. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 759 EAST 81ST AVENUE, Merrillville, IN 46410. 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 |
|---|---|---|
| 18002462B | IN | Vision Therapy Optometrist primary |
| 18002462A | IN | Optometrist |
This provider holds licence 18002462B issued in IN. 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 Vision Therapy covers
Optometrists who specialize in vision therapy as a treatment process used to improve vision function. It includes a broad range of developmental and rehabilitative treatment programs individually prescribed to remediate specific sensory, motor and/or visual perceptual dysfunctions. NUCC Health Care Provider Taxonomy, code 152WV0400X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 152WV0400X | Vision Therapy Optometrist Vision Therapy | 18002462B | IN | primary |
| 152W00000X | Optometrist | 18002462A | IN |
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 | 1669599403 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 26, 2007 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | OPTOMETRIST OD DEGRE |
| Practice address |
759 EAST 81ST AVENUE Merrillville, IN 46410 (219) 736-0013 Fax (219) 769-8842 |
| Mailing address |
823 WEST 89TH PLACE Merrillville, IN 46410 |
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 | 6 | 9 | 5 | 9 | 9 | 4 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 3 | 9 | 1 | 9 | 9 | 4 | 0 |
Sum = 67 · next multiple of 10 = 70 · check digit = 3 · actual last digit = 3
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.