Quick answers
- Does Grace M. Niziolek accept Medicare assignment?
- Yes. Medicare's clinician data says Grace M. Niziolek 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 Grace M. Niziolek see?
- In 2024, CMS data shows 198 Original Medicare patients and 357 services for Grace M. Niziolek. This counts Original Medicare only and measures volume, not quality.
- What is Grace M. Niziolek's NPI number?
- 1528486339. 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 Grace M. Niziolek, 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 | 198 |
|---|---|
| Services billed to Medicare | 357 |
| Different services or procedures | 28 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes (99231)166 services
- Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes (99222)47 services
- Critical care, first 30-74 minutes (99291)41 services
- Initial hospital care with straightforward or low level of medical decision making, per day, if using time, at least 40 minutes (99221)29 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%
- Arthritis65%
- Chronic kidney disease53%
- Anxiety48%
- Diabetes46%
Hospitals where Grace M. Niziolek works
Medicare's Facility Affiliation Data lists Grace M. Niziolek 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.
- Alton Memorial HospitalAlton, IL · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 140002
- Barnes Jewish HospitalSaint Louis, MO · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 260032
- Christian Hospital NortheastSaint Louis, MO · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 260180
- Memorial HospitalBelleville, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140185
- Missouri Baptist Medical CenterSaint Louis, MO · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 260108
Practice locations
Addresses where Grace M. Niziolek is enrolled with Medicare (CMS data updated October 2, 2026).
- 1 Barnes Jew Hosp PlzSaint Louis, MO 63110 (314) 747‑3000
Group practices
Medicare enrollment lists Grace M. Niziolek as a member of this group (CMS data updated October 2, 2026).
- Washington University3,029 clinicians in the group
Specialties
- General Surgeryprimary
- Anesthesiologyalso
- Critical Care (Intensivists)also
Other general surgeons in Saint Louis
Clinicians with the same Medicare primary specialty in Saint Louis, MO — not a recommendation.
Other clinicians in Washington University
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2014 (12 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1528486339 |
| 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