Quick answers
- Does Karl P. Undesser accept Medicare assignment?
- Yes. Medicare's clinician data says Karl P. Undesser 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 Karl P. Undesser see?
- In 2024, CMS data shows 764 Original Medicare patients and 2,463 services for Karl P. Undesser. This counts Original Medicare only and measures volume, not quality.
- What is Karl P. Undesser's NPI number?
- 1013961242. 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 Karl P. Undesser, 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 patients | 764 |
|---|---|
| Services billed to Medicare | 2,463 |
| Different services or procedures | 54 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)733 services
- Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report (93000)251 services
- Programming of dual lead pacemaker system (93280)173 services
- Ultrasound of heart with color-depicted blood flow, rate, direction and valve function (93306)168 services
- Evaluation of single, dual, multiple lead or leadless pacemaker system or implantable defibrillator system, remote up to 90 days (93296)156 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 blood pressure75%
- High cholesterol75%
- Atrial fibrillation51%
- Arthritis50%
- Heart failure30%
- Ischemic heart disease28%
Hospitals where Karl P. Undesser works
Medicare's Facility Affiliation Data lists Karl P. Undesser 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.
- St Luke's Nampa Medical CenterNampa, ID · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 130071
- St Luke's Regional Medical CenterBoise, ID · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 130006
- Weiser Memorial HospitalWeiser, ID · Critical Access Hospital · Emergency services: listed by Medicare · CCN 131307
- West Valley Medical CenterCaldwell, ID · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 130014
Practice locations
Addresses where Karl P. Undesser is enrolled with Medicare (CMS data updated October 2, 2026).
- 1906 Fairview Ave, Suite 230Caldwell, ID 83605 (208) 459‑0028
Group practices
Medicare enrollment lists Karl P. Undesser as a member of this group (CMS data updated October 2, 2026).
- West Valley Medical Group Specialty Services LLC5 clinicians in the group
Specialties
Other cardiac electrophysiologists in Idaho
Clinicians with the same Medicare primary specialty in Idaho — not a recommendation.
Other clinicians in West Valley Medical Group Specialty Services LLC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Texas Medical School At San Antonio |
| Graduation year | 1989 (37 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1013961242 |
| 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 October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- 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