Ryan D. Holzmacher, MD

Medicare activity in 2024

Official CMS public-use data for Ryan D. Holzmacher, 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.

Most frequent services

1. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)2,879 services
2. Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)383 services
3. Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)345 services
4. Subsequent nursing facility care with moderate level of medical decision making, per day, if using time, at least 30 minutes (99309)319 services
5. Initial nursing facility care with high level of medical decision making, per day, if using time, 50 minutes or more (99306)110 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%
• Arthritis61%
• Depression51%
• Chronic kidney disease49%
• Ischemic heart disease47%

Hospitals where Ryan D. Holzmacher works

Medicare's Facility Affiliation Data lists Ryan D. Holzmacher 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.

• Waukesha Memorial HospitalWaukesha, WI · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 520008

Practice locations

Addresses where Ryan D. Holzmacher is enrolled with Medicare (CMS data updated October 2, 2026).

• 18740 W Bluemound RdBrookfield, WI 53045 (262) 782‑0230

Group practices

Medicare enrollment lists Ryan D. Holzmacher as a member of this group (CMS data updated October 2, 2026).

• Oak Medical SC123 clinicians in the group

Specialties

• Internal Medicineprimary
• Nephrologyalso

Find other Internal Medicine doctors in Wisconsin →

Other internal medicine doctors in Brookfield

Clinicians with the same Medicare primary specialty in Brookfield, WI — not a recommendation.

• Jyoti Saluja, MD
• Stephanie M. Strohbeen, MD
• Jeffery S. Postles, MD
• Sarah Mann, MD
• Leo Taiberg, MD
• Christopher R. Lieb, MD
• Gregory P. Spielbauer, MD
• Timothy C. Cooper, MD

All internal medicine doctors in Brookfield →

Other clinicians in Oak Medical SC

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

• Stephanie Antes
• Sheri Erickson, NP
• Megan M. Buboltz, PA
• Whitney Hoffmann, DO
• Kaitlyn M. Handel
• Sara M. Peters

Clinician information

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