Quick answers
- Where does Mark Den Hartog see patients?
- Medicare's clinician data lists 2 practice locations, including Olympia, WA and Roseburg, OR. Call before your visit to confirm the address.
- What is Mark Den Hartog's specialty?
- Medicare lists Chiropractic as the primary specialty.
- Does Mark Den Hartog accept Medicare assignment?
- Medicare's clinician data says Mark Den Hartog may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is Mark Den Hartog's NPI number?
- 1023081155. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where Mark Den Hartog is enrolled with Medicare (CMS data updated 2026-10-02).
Specialties
- Chiropracticprimary
Other chiropractors in Olympia
Clinicians with the same Medicare primary specialty in Olympia, WA — not a recommendation.
Clinician information
| Credential | DC |
|---|---|
| Medical school | Northwestern College Of Chiropractic |
| Graduation year | 1992 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1023081155 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians