Simon Maltais, MD
Simon Maltais, MD is a Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician in Thousand Oaks, CA, registered under NPI 1457665911. 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 227 W JANSS RD STE 340, Thousand Oaks, CA 91360. 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 |
|---|---|---|
| 53401 | MN | Thoracic Surgery (Cardiothoracic Vascular… primary |
| MD47528 | TN | Vascular Surgery Physician |
| 65433 | WI | Thoracic Surgery (Cardiothoracic Vascular… |
| MD47528 | TN | Thoracic Surgery (Cardiothoracic Vascular… |
Licences are recorded in 3 states: MN, TN, WI. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Cardiac Surgery
- PAC ID
- 0840486510
Enrolled in Medicare 3 times, across 3 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Wisconsin | I20171117000009 | Practitioner - Cardiac Surgery |
| Montana | I20211104002666 | Practitioner - Thoracic Surgery |
| Colorado | I20250626000325 | Practitioner - Cardiac Surgery |
Medicare enrolment is recorded as approved under the provider type Practitioner - Cardiac Surgery. There are 3 separate enrolment records across 3 states (WI, MT, CO). Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. 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 3 states
This provider holds licences in 3 states: Minnesota, Tennessee and Wisconsin. 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 Thoracic Surgery (Cardiothoracic Vascular Surgery) covers
A thoracic surgeon provides the operative, perioperative and critical care of patients with pathologic conditions within the chest. Included is the surgical care of coronary artery disease, cancers of the lung, esophagus and chest wall, abnormalities of the trachea, abnormalities of the great vessels and heart valves, congenital anomalies, tumors of the mediastinum and diseases of the diaphragm. The management of the airway and injuries of the chest is within the scope of the specialty. NUCC Health Care Provider Taxonomy, code 208G00000X
All registered taxonomy codes
This provider registers 4 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 208G00000X | Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician | 53401 | MN | primary |
| 2086S0129X | Vascular Surgery Physician Vascular Surgery | MD47528 | TN | |
| 208G00000X | Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician | 65433 | WI | |
| 208G00000X | Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician | MD47528 | TN |
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 | 1457665911 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 27, 2010 |
| Last updated | May 20, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
227 W JANSS RD STE 340 Thousand Oaks, CA 91360 (805) 852-9100 Fax (805) 852-9101 |
| Other identifiers |
ENROLLED
· Medicaid (MN) |
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 | 4 | 5 | 7 | 6 | 6 | 5 | 9 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 1 | 7 | 3 | 6 | 1 | 9 | 2 |
Sum = 59 · next multiple of 10 = 60 · check digit = 1 · actual last digit = 1
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.