Quick answers
- Does Frederick W. Penczak accept Medicare assignment?
- Yes. Medicare's clinician data says Frederick W. Penczak 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 Frederick W. Penczak see?
- In 2024, CMS data shows 358 Original Medicare patients and 463 services for Frederick W. Penczak. This counts Original Medicare only and measures volume, not quality.
- What is Frederick W. Penczak's NPI number?
- 1841379070. 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 Frederick W. Penczak, 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 | 358 |
|---|---|
| Services billed to Medicare | 463 |
| Different services or procedures | 77 |
| Participating Medicare provider | Yes |
| Average age of these patients | 76 |
Most frequent services
- Replacement of thigh bone and hip joint with prosthesis (27130)128 services
- Replacement of knee joint, both sides of knee (27447)99 services
- Treatment of upper end of broken thigh bone with placement of stabilizing device or prosthetic replacement (27236)30 services
- Treatment of broken neck of thigh bone with bone implant (27245)18 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 cholesterol75%
- Arthritis75%
- High blood pressure66%
- Depression28%
- Anxiety28%
- Ischemic heart disease27%
Hospitals where Frederick W. Penczak works
Medicare's Facility Affiliation Data lists Frederick W. Penczak 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.
- Marinhealth Medical CenterGreenbrae, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050360
- Novato Community HospitalNovato, CA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 050131
Practice locations
Addresses where Frederick W. Penczak is enrolled with Medicare (CMS data updated October 2, 2026).
- 180 Rowland WayNovato, CA 94945 (415) 209‑1300
- 250 Bon Air RdGreenbrae, CA 94904 (415) 925‑7000
Specialties
- General Surgeryprimary
- Neurosurgeryalso
- Orthopedic Surgeryalso
Other general surgeons in Novato
Clinicians with the same Medicare primary specialty in Novato, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Medical College Of Pennsylvania |
| Graduation year | 1999 (27 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1841379070 |
| 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