Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Internal Medicine

Bryan C. Gieszl, MD

Works at hospitals in Aspen, CO · Glenwood Springs, CO · Colorado

Summary

Dr. Bryan C. Gieszl, MD is an internal medicine doctor at 401 Castle Creek Rd, Aspen, CO 81611. Phone: (970) 544-1120. Accepts Medicare assignment. In 2024, Bryan C. Gieszl had 479 Original Medicare patients and 2,169 services. NPI 1881644649. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

  • Specialty: Internal medicine doctor (Medicare lists Internal Medicine)
  • Address: 401 Castle Creek Rd, Aspen, CO 81611 · Directions
  • Phone: (970) 544‑1120
  • Medicare: Accepts Medicare assignment
  • Hospitals: Aspen Valley Hospital District, Valley View Hospital Association
  • Group practice: Aspen Valley Hospital Clinics, PLLC
  • Medical school: University Of California, Geffen School Of Medicine · graduated 2003 (23 years since medical school)
  • Gender (as listed): Male
  • Telehealth: offered

From official Medicare data

This page shows what Medicare's official clinician data says about Bryan C. Gieszl, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Bryan C. Gieszl accept Medicare assignment?
Yes. Medicare's clinician data says Bryan C. Gieszl accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
How many Medicare patients does Bryan C. Gieszl see?
In 2024, CMS data shows 479 Original Medicare patients and 2,169 services for Bryan C. Gieszl. This counts Original Medicare only and measures volume, not quality.
What is Bryan C. Gieszl's NPI number?
1881644649. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Medicare activity in 2024

Official CMS public-use data for Bryan C. Gieszl, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Original Medicare patients479
Services billed to Medicare2,169
Different services or procedures41
Participating Medicare providerYes
Average age of these patients75

Most frequent services

  1. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)616 services
  2. Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)425 services
  3. Annual alcohol misuse screening, 5 to 15 minutes (G0442)160 services
  4. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)125 services
  5. Annual depression screening, 5 to 15 minutes (G0444)123 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

  • High cholesterol61%
  • Arthritis46%
  • High blood pressure39%
  • Ischemic heart disease22%
  • Osteoporosis17%
  • Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)14%

Hospitals where Bryan C. Gieszl works

Medicare's Facility Affiliation Data lists Bryan C. Gieszl at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

Practice locations

Addresses where Bryan C. Gieszl is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Bryan C. Gieszl as a member of this group (CMS data updated October 2, 2026).

  • Aspen Valley Hospital Clinics, PLLC23 clinicians in the group

Specialties

Find other Internal Medicine doctors in Colorado →

Other internal medicine doctors in Aspen

Clinicians with the same Medicare primary specialty in Aspen, CO — not a recommendation.

All internal medicine doctors in Aspen →

Other clinicians in Aspen Valley Hospital Clinics, PLLC

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialMD
Medical schoolUniversity Of California, Geffen School Of Medicine
Graduation year2003 (23 years since medical school)
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
TelehealthOffers telehealth services
NPI (National Provider Identifier)1881644649
CorrectionsReport 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

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
  2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
  3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  6. Medicare Care Compare — official Medicare tool to look up clinicians