Quick answers
- Where does Gregory K. Nielsen see patients?
- Medicare's clinician data lists 1 practice location in Highlands Ranch, CO. Call before your visit to confirm the address.
- What is Gregory K. Nielsen's specialty?
- Medicare lists Psychiatry as the primary specialty.
- Does Gregory K. Nielsen accept Medicare assignment?
- Yes. Medicare's clinician data says Gregory K. Nielsen 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 Gregory K. Nielsen?
- (303) 338-4545, as listed in official Medicare / NPI Registry data.
- What is Gregory K. Nielsen's NPI number?
- 1851910087. 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 Gregory K. Nielsen is enrolled with Medicare (CMS data updated 2026-10-02).
- 9285 Hepburn StHighlands Ranch, CO 80129 (303) 338‑4545
Group practices
Medicare enrollment lists Gregory K. Nielsen as a member of this group (CMS data updated 2026-10-02).
- Colorado Permanente Medical Group PC1,327 clinicians in the group
Specialties
- Psychiatryprimary
Other psychiatrists in Highlands Ranch
Clinicians with the same Medicare primary specialty in Highlands Ranch, CO — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | Michigan State University College Of Osteopathic Medicine |
| Graduation year | 2020 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1851910087 |
| 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