Quick answers
- Does Mosen Istwani accept Medicare assignment?
- Yes. Medicare's clinician data says Mosen Istwani 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 Mosen Istwani see?
- In 2024, CMS data shows 147 Original Medicare patients and 1,325 services for Mosen Istwani. This counts Original Medicare only and measures volume, not quality.
- What is Mosen Istwani's NPI number?
- 1043229453. 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 Mosen Istwani, 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 | 147 |
|---|---|
| Services billed to Medicare | 1,325 |
| Different services or procedures | 13 |
| Participating Medicare provider | Yes |
| Average age of these patients | 72 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes (99232)1,042 services
- Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)118 services
- Hemodialysis procedure with physician evaluation (90935)69 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%
- Diabetes75%
- Chronic kidney disease75%
- Heart failure75%
- Ischemic heart disease64%
Hospitals where Mosen Istwani works
Medicare's Facility Affiliation Data lists Mosen Istwani 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.
- Corona Regional Medical CenterCorona, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050329
- Parkview Community Hospital Medical CenterRiverside, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050102
- Riverside Community HospitalRiverside, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 050022
Practice locations
Addresses where Mosen Istwani is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 6; the Medicare profile lists all.
- 2224 Medical Ctr DrPerris, CA 92571 (951) 436‑3535
- 3865 Jackson StRiverside, CA 92503 (951) 688‑2211
- 4445 Magnolia AveRiverside, CA 92501 (951) 788‑3000
- 613 S Howard StCorona, CA 92879 (951) 735‑1257
- 7275 Indiana Ave, Suite 200Riverside, CA 92504 (951) 343‑1978
Group practices
Medicare enrollment lists Mosen Istwani as a member of this group (CMS data updated October 2, 2026).
- Riverside Nephrology Physicians Inc3 clinicians in the group
Specialties
- Internal Medicineprimary
- Nephrologyalso
Other internal medicine doctors in Perris
Clinicians with the same Medicare primary specialty in Perris, CA — not a recommendation.
Other clinicians in Riverside Nephrology Physicians Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1990 (36 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1043229453 |
| 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