Quick answers
- Does Mary J. Derse-Hayes accept Medicare assignment?
- Yes. Medicare's clinician data says Mary J. Derse-Hayes 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 Mary J. Derse-Hayes see?
- In 2024, CMS data shows 56 Original Medicare patients and 74 services for Mary J. Derse-Hayes. This counts Original Medicare only and measures volume, not quality.
- What is Mary J. Derse-Hayes's NPI number?
- 1679675557. 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 Mary J. Derse-Hayes, 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 | 56 |
|---|---|
| Services billed to Medicare | 74 |
| Different services or procedures | 8 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)33 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)16 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 pressure70%
- High cholesterol68%
- Arthritis52%
- Osteoporosis29%
- Chronic kidney disease23%
- Diabetes21%
Hospitals where Mary J. Derse-Hayes works
Medicare's Facility Affiliation Data lists Mary J. Derse-Hayes 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 Memorial Lutheran HospitalMilwaukee, WI · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 520177
Practice locations
Addresses where Mary J. Derse-Hayes is enrolled with Medicare (CMS data updated October 2, 2026).
- 1155 N Mayfair RdWauwatosa, WI 53226 (414) 955‑5990
- 1700 W Paradise DrWest Bend, WI 53095 (262) 334‑3451
- 4805 S Moorland RdNew Berlin, WI 53151 (262) 798‑7200
- W168n11237 Western AveGermantown, WI 53022 (262) 253‑5060
Group practices
Medicare enrollment lists Mary J. Derse-Hayes as a member of this group (CMS data updated October 2, 2026).
- Froedtert Andthe Medical College of Wisconsin Community Physicians Inc1,285 clinicians in the group
Specialties
- Physician Assistantprimary
Other physician assistants in Wauwatosa
Clinicians with the same Medicare primary specialty in Wauwatosa, WI — not a recommendation.
Other clinicians in Froedtert Andthe Medical College of Wisconsin Community Physicians Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Graduation year | 2006 |
|---|---|
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1679675557 |
| 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