Quick answers
- Does William S. Zillweger accept Medicare assignment?
- Yes. Medicare's clinician data says William S. Zillweger 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 William S. Zillweger see?
- In 2024, CMS data shows 132 Original Medicare patients and 444 services for William S. Zillweger. This counts Original Medicare only and measures volume, not quality.
- What is William S. Zillweger's NPI number?
- 1285607002. 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 William S. Zillweger, 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 | 132 |
|---|---|
| Services billed to Medicare | 444 |
| Different services or procedures | 28 |
| Participating Medicare provider | Yes |
| Average age of these patients | 85 |
Most frequent services
- Subsequent nursing facility care with high level of medical decision making, per day, if using time, at least 45 minutes (99310)103 services
- Subsequent nursing facility care with moderate level of medical decision making, per day, if using time, at least 30 minutes (99309)81 services
- Initial nursing facility care with high level of medical decision making, per day, if using time, 50 minutes or more (99306)57 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)56 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)45 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 cholesterol66%
- Arthritis57%
- Anxiety39%
- Depression38%
- Atrial fibrillation36%
Hospitals where William S. Zillweger works
Medicare's Facility Affiliation Data lists William S. Zillweger 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.
- Independence Health System Butler Memorial HospitaButler, PA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 390168
- UPMC PassavantPittsburgh, PA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 390107
Practice locations
Addresses where William S. Zillweger is enrolled with Medicare (CMS data updated October 2, 2026).
- 9104 Babcock Blvd, Suite 3111Pittsburgh, PA 15237 (412) 366‑2960
Group practices
Medicare enrollment lists William S. Zillweger as a member of this group (CMS data updated October 2, 2026).
- Genesis Medical Associates, Inc.100 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Pittsburgh
Clinicians with the same Medicare primary specialty in Pittsburgh, PA — not a recommendation.
Other clinicians in Genesis Medical Associates, Inc.
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1982 (44 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1285607002 |
| 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