Nickolas S Demark, DO
Nickolas S Demark, DO is an Internal Medicine in Oskaloosa, Iowa. Graduated from Des Moines University of Osteopathic Medicine and Health Sciences in 2011, 15 years ago. Practices with Mahaska County Hospital, a 124-clinician group, works from 7 locations and accepts Medicare assignment. Licensed in Iowa, Michigan and Wisconsin.
- Years since qualifying
- 15
- Trained at
- Des Moines University of Osteopathic Medicine and Health Sciences
- Licensed in
- IA, MI, WI
- In the registry since
- 2011
- Specialties on file
- 4
What do these letters mean?
- DO — Doctor of Osteopathic Medicine
- A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.
Practice location Address checks out
1229 C Ave EOskaloosa, IA 52577-4246
Phone: (641) 672-3100
Fax: (641) 672-3381
Show map & directions
Directions in Google Maps · Apple Maps · OpenStreetMap
Pin is approximate — placed at the ZIP-code centre, not the exact door.
Additional practice locations (6)
- 1818 N Meade St, Appleton, WI 54911-3454 — (920) 735-7645
- 1715 Dousman St, Green Bay, WI 54303-3211 — (920) 496-4700
- 1726 Shawano Ave, Green Bay, WI 54303-3216 — (920) 496-4700
- 130 2nd St, Neenah, WI 54956-2883 — (920) 729-2738
- 900 Illinois Ave, Stevens Point, WI 54481-3114 — (715) 346-5000
- 900 Illinois Ave, Stevens Point, WI 54481-3114 — (715) 346-5000
Specialties & licences
| Hospice and Palliative Medicine (Internal Medicine) Physician (primary) | Taxonomy 207RH0002X · Licence DO-06639 (IA) |
|---|---|
| Hospitalist Physician | Taxonomy 208M00000X · Licence 62482 (WI) |
| Internal Medicine Physician | Taxonomy 207R00000X · Licence 62482 (WI) |
| Internal Medicine Physician | Taxonomy 207R00000X · Licence 5101019580 (MI) |
Record details
| NPI number | 1114214004 |
|---|---|
| Entity type | Individual (Type 1) |
| Gender | Male |
| Credentials | DO |
| Sole proprietor | No |
| NPI enumerated | June 30, 2011 |
| Last updated in NPPES | July 1, 2026 |
| Certification date | July 1, 2026 |
| Mailing address | 1229 C Ave E, Oskaloosa, IA 52577-4298 |
Medicare enrollment
| Medicare specialty | INTERNAL MEDICINE |
|---|---|
| Also practises | HOSPICE/PALLIATIVE CARE |
| Medical school | DES MOINES UNIVERSITY OF OSTEOPATHIC MEDICINE AND HEALTH SCIENCES |
| Graduated | 2011 (15 years in practice) |
| Group practice | Mahaska County Hospital — 124 clinicians |
| Accepts Medicare assignment | Yes — accepts the Medicare-approved amount |