Quick answers
- Which hospitals does Nickolas S. Demark work at?
- Medicare's official clinician data lists Nickolas S. Demark at 1 hospital: Mahaska Health Partnership. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Nickolas S. Demark see patients?
- Medicare's clinician data lists 1 practice location in Oskaloosa, IA. Call before your visit to confirm the address.
- What is Nickolas S. Demark's specialty?
- Medicare lists Internal Medicine as the primary specialty, and also Hospice/Palliative Care.
- Does Nickolas S. Demark accept Medicare assignment?
- Yes. Medicare's clinician data says Nickolas S. Demark accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Nickolas S. Demark?
- (641) 672-3100, as listed in official Medicare / NPI Registry data.
- What is Nickolas S. Demark's NPI number?
- 1114214004. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Nickolas S. Demark works
Medicare's Facility Affiliation Data lists Nickolas S. Demark at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Mahaska Health PartnershipOskaloosa, IA · Critical Access Hospital · CCN 161379
Practice locations
Addresses where Nickolas S. Demark is enrolled with Medicare (CMS data updated 2026-10-02).
- 1229 C Ave E, Mahaska HealthOskaloosa, IA 52577 (641) 672‑3100
Group practices
Medicare enrollment lists Nickolas S. Demark as a member of this group (CMS data updated 2026-10-02).
- Mahaska County Hospital128 clinicians in the group
Specialties
- Internal Medicineprimary
- Hospice/Palliative Carealso
Other internal medicine doctors in Oskaloosa
Clinicians with the same Medicare primary specialty in Oskaloosa, IA — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | Des Moines University Of Osteopathic Medicine And Health Sciences |
| Graduation year | 2011 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1114214004 |
| 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- 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