Theodor Asgeirsson, MD
Theodor Asgeirsson, MD is a Colon & Rectal Surgery Physician in Greenville, MI, registered under NPI 1255480067. 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 421 S BALDWIN ST, Greenville, MI 48838. 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 |
|---|---|---|
| 217561 | MA | Surgery Physician |
| A112879 | CA | Colon & Rectal Surgery Physician primary |
Licences are recorded in 2 states: MA, CA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Colorectal Surgery (proctology)
- PAC ID
- 7416145511
- Enrollment ID
- I20101215001056
Medicare enrolment is recorded as approved under the provider type Practitioner - Colorectal Surgery (proctology). 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 Massachusetts. Multi-state licensure often means the provider works near a state border, covers more than one office, or delivers care 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 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 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 | |
|---|---|---|---|---|
| 208600000X | Surgery Physician | 217561 | MA | |
| 208C00000X | Colon & Rectal Surgery Physician | A112879 | CA | 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 | 1255480067 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jan 10, 2007 |
| Last updated | Sep 19, 2012 |
| Status | Active |
| Sole proprietor | No |
| Gender | Male |
| Credential | MD |
| Practice address |
421 S BALDWIN ST Greenville, MI 48838 (616) 225-8667 |
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 | 5 | 5 | 4 | 8 | 0 | 0 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 1 | 5 | 8 | 8 | 0 | 0 | 3 |
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.