Quick answers
- Does Erik P. Gierahn accept Medicare assignment?
- Yes. Medicare's clinician data says Erik P. Gierahn 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 Erik P. Gierahn see?
- In 2024, CMS data shows 361 Original Medicare patients and 602 services for Erik P. Gierahn. This counts Original Medicare only and measures volume, not quality.
- What is Erik P. Gierahn's NPI number?
- 1255368189. 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 Erik P. Gierahn, 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 | 361 |
|---|---|
| Services billed to Medicare | 602 |
| Different services or procedures | 13 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (93010)252 services
- Emergency department visit with high level of medical decision making (99285)157 services
- Emergency department visit with moderate level of medical decision making (99284)117 services
- Critical care, first 30-74 minutes (99291)33 services
- Emergency department visit with low level of medical decision making (99283)23 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%
- Arthritis49%
- Chronic kidney disease40%
- Ischemic heart disease37%
- Anxiety35%
Hospitals where Erik P. Gierahn works
Medicare's Facility Affiliation Data lists Erik P. Gierahn 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.
- Froedtert Community HospitalNew Berlin, WI · Acute Care Hospital · Emergency services: listed by Medicare · CCN 520213
- St Josephs Community Hospital West BendWest Bend, WI · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 520063
Practice locations
Addresses where Erik P. Gierahn is enrolled with Medicare (CMS data updated October 2, 2026).
- 3200 Pleasant Valley RdWest Bend, WI 53095 (262) 836‑7300
- 3212 Pleasant Valley RdWest Bend, WI 53095 (262) 334‑6165
- 8701 W Watertown PlankMilwaukee, WI 53226 (414) 805‑3666
- 8701 Watertown Plank Rd, Room 4041 MfrcMilwaukee, WI 53226 (414) 805‑3666
Group practices
Medicare enrollment lists Erik P. Gierahn as a member of these groups (CMS data updated October 2, 2026).
- The Medical College of Wisconsin Inc2,115 clinicians in the group
- Froedtert Andthe Medical College of Wisconsin Community Physicians Inc1,285 clinicians in the group
Specialties
- Emergency Medicineprimary
Other emergency medicine doctors in West Bend
Clinicians with the same Medicare primary specialty in West Bend, WI — not a recommendation.
Other clinicians in The Medical College of Wisconsin Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Wisconsin School Of Medicine |
| Graduation year | 2003 (23 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1255368189 |
| 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