Quick answers
- Which hospitals does Mark A. Siemer work at?
- Medicare's official clinician data lists Mark A. Siemer at 1 hospital: St Anthony Summit Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark A. Siemer see patients?
- Medicare's clinician data lists 1 practice location in Silverthorne, CO. Call before your visit to confirm the address.
- What is Mark A. Siemer's specialty?
- Medicare lists Family Practice as the primary specialty.
- Does Mark A. Siemer accept Medicare assignment?
- Yes. Medicare's clinician data says Mark A. Siemer 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 Mark A. Siemer?
- (970) 468-1003, as listed in official Medicare / NPI Registry data.
- What is Mark A. Siemer's NPI number?
- 1871649368. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Mark A. Siemer works
Medicare's Facility Affiliation Data lists Mark A. Siemer at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- St Anthony Summit Medical CenterFrisco, CO · Acute Care Hospital · CCN 060118
Practice locations
Addresses where Mark A. Siemer is enrolled with Medicare (CMS data updated 2026-10-02).
- 265 Tanglewood Ln, 1 Prsv Pe SilverthorneSilverthorne, CO 80498 (970) 468‑1003
Group practices
Medicare enrollment lists Mark A. Siemer as a member of this group (CMS data updated 2026-10-02).
- Catholic Health Initiatives Colorado1,225 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Colorado
Clinicians with the same Medicare primary specialty in Colorado — not a recommendation.
Clinician information
| Credential | DO |
|---|---|
| Medical school | Nova Southeastern College Of Osteo Medicine |
| Graduation year | 1994 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1871649368 |
| 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