Quick answers
- Does Mariusz Niedzwiecki accept Medicare assignment?
- Yes. Medicare's clinician data says Mariusz Niedzwiecki 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 Mariusz Niedzwiecki see?
- In 2024, CMS data shows 158 Original Medicare patients and 329 services for Mariusz Niedzwiecki. This counts Original Medicare only and measures volume, not quality.
- What is Mariusz Niedzwiecki's NPI number?
- 1083281679. 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 Mariusz Niedzwiecki, 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 | 158 |
|---|---|
| Services billed to Medicare | 329 |
| Different services or procedures | 42 |
| Participating Medicare provider | Yes |
| Average age of these patients | 74 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)60 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)30 services
- New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)26 services
- Insertion of needle into vein for collection of blood sample (36415)23 services
- Detection test by immunoassay with direct visual observation for influenza virus (87804)22 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 cholesterol63%
- Arthritis48%
- Diabetes33%
- Chronic kidney disease23%
- Ischemic heart disease20%
Hospitals where Mariusz Niedzwiecki works
Medicare's Facility Affiliation Data lists Mariusz Niedzwiecki 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.
- Grossmont HospitalLa Mesa, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050026
Practice locations
Addresses where Mariusz Niedzwiecki is enrolled with Medicare (CMS data updated October 2, 2026).
- 10243 Genetic Ctr DrSan Diego, CA 92121 (858) 499‑2600
- 5555 Grossmont Ctr DrLa Mesa, CA 91942 (619) 465‑0711
- 8851 Ctr Dr, Suite 600La Mesa, CA 91942 (619) 740‑5724
Group practices
Medicare enrollment lists Mariusz Niedzwiecki as a member of these groups (CMS data updated October 2, 2026).
- Sharp Rees-Stealy Medical Group Inc884 clinicians in the group
- Team Physicians of Northern California Medical Group Inc85 clinicians in the group
- Clinic Services of California Medical Group Inc61 clinicians in the group
Specialties
- Nurse Practitionerprimary
Other nurse practitioners in San Diego
Clinicians with the same Medicare primary specialty in San Diego, CA — not a recommendation.
Other clinicians in Sharp Rees-Stealy Medical Group Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | NP |
|---|---|
| Graduation year | 2020 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1083281679 |
| 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