Marc Greenwald, MD
Marc Greenwald, MD is a Colon & Rectal Surgery Physician in Great Neck, NY, registered under NPI 1174618557. 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 310 EAST SHORE ROAD SUTE 203, Great Neck, NY 11023. 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 |
|---|---|---|
| 166588 | NY | Colon & Rectal Surgery Physician primary |
| 166588 | NY | Surgery Physician |
This provider holds licence 166588 issued in NY. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - General Surgery
- PAC ID
- 2062579097
- Enrollment ID
- I20090319000062
Medicare enrolment is recorded as approved under the provider type Practitioner - General Surgery. 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.
What Colon & Rectal Surgery covers
A colon and rectal surgeon is trained to diagnose and treat various diseases of the intestinal tract, colon, rectum, anal canal and perianal area by medical and surgical means. This specialist also deals with other organs and tissues (such as the liver, urinary and female reproductive system) involved with primary intestinal disease. NUCC Health Care Provider Taxonomy, code 208C00000X
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 | |
|---|---|---|---|---|
| 208C00000X | Colon & Rectal Surgery Physician | 166588 | NY | primary |
| 208600000X | Surgery Physician | 166588 | 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 | 1174618557 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Oct 3, 2006 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
310 EAST SHORE ROAD SUTE 203 Great Neck, NY 11023 (516) 482-8657 Fax (516) 829-0002 |
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 | 1 | 7 | 4 | 6 | 1 | 8 | 5 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 5 | 4 | 3 | 1 | 7 | 5 | 1 |
Sum = 53 · next multiple of 10 = 60 · 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.