Cristin Opreanu, MD
Cristin Opreanu, MD is a Colon & Rectal Surgery Physician in Lansing, MI, registered under NPI 1235375585. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty. 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 1627 LAKE LANSING RD STE 100, Lansing, MI 48912. 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 |
|---|---|---|
| 4301093541 | MI | Colon & Rectal Surgery Physician primary |
| 4301093541 | MI | Surgery Physician |
This provider holds licence 4301093541 issued in MI. 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
- 0840598553
Medicare enrolment is recorded as approved under the provider type Practitioner - General Surgery. This means the provider is enrolled to bill Medicare, though 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 | 4301093541 | MI | primary |
| 208600000X | Surgery Physician | 4301093541 | MI |
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 | 1235375585 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Dec 16, 2008 |
| Last updated | May 28, 2026 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
1627 LAKE LANSING RD STE 100 Lansing, MI 48912 (517) 372-0500 Fax (517) 482-3220 |
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 | 2 | 3 | 5 | 3 | 7 | 5 | 5 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 6 | 5 | 6 | 7 | 1 | 5 | 7 |
Sum = 65 · next multiple of 10 = 70 · check digit = 5 · actual last digit = 5
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.