Mark Ash, DDS
Mark Ash, DDS is a provider specialising in Oral and Maxillofacial Surgery (Dentist) in Duluth, MN, registered under NPI 1164045738. 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 3617 W ARROWHEAD RD, Duluth, MN 55811. 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 |
|---|---|---|
| D14360 | MN | Oral and Maxillofacial Surgery (Dentist) primary |
| 6001917-15 | WI | Oral and Maxillofacial Surgery (Dentist) |
Licences are recorded in 2 states: MN, WI. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Oral Surgery
- PAC ID
- 1951727981
Medicare enrolment is recorded as approved under the provider type Practitioner - Oral 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.
Licensed in 2 states
This provider holds licences in 2 states: Minnesota and Wisconsin. The practice address on file is in Duluth, MN, 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
- D14360
- Specialty
- Oral and Maxillofacial Surgery (Dentist)
- Licence
- 6001917-15
- Specialty
- Oral and Maxillofacial Surgery (Dentist)
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 Oral and Maxillofacial Surgery covers
The specialty of dentistry which includes the diagnosis, surgical and adjunctive treatment of diseases, injuries and defects involving both the functional and esthetic aspects of the hard and soft tissues of the oral and maxillofacial region. NUCC Health Care Provider Taxonomy, code 1223S0112X
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 | |
|---|---|---|---|---|
| 1223S0112X | Oral and Maxillofacial Surgery (Dentist) Oral and Maxillofacial Surgery | D14360 | MN | primary |
| 1223S0112X | Oral and Maxillofacial Surgery (Dentist) Oral and Maxillofacial Surgery | 6001917-15 | WI |
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 | 1164045738 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 18, 2020 |
| Last updated | Aug 22, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | DDS |
| Practice address |
3617 W ARROWHEAD RD Duluth, MN 55811 (218) 722-8377 |
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 | 6 | 4 | 0 | 4 | 5 | 7 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 3 | 4 | 0 | 4 | 1 | 7 | 6 |
Sum = 52 · next multiple of 10 = 60 · check digit = 8 · actual last digit = 8
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.