Quick answers
- Does Dheeraj Mahajan accept Medicare assignment?
- Yes. Medicare's clinician data says Dheeraj Mahajan 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 Dheeraj Mahajan see?
- In 2024, CMS data shows 3,867 Original Medicare patients and 12,468 services for Dheeraj Mahajan. This counts Original Medicare only and measures volume, not quality.
- What is Dheeraj Mahajan's NPI number?
- 1831133693. 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 Dheeraj Mahajan, 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 | 3,867 |
|---|---|
| Services billed to Medicare | 12,468 |
| Different services or procedures | 13 |
| Participating Medicare provider | Yes |
| Average age of these patients | 79 |
Most frequent services
- Admn sarscov2 vacc 1 dose (90480)3,854 services
- Sarscv2 vac 30mcg trs-suc im (91320)2,477 services
- Administration of influenza virus vaccine (G0008)2,135 services
- Influenza vaccine, inactivated (90653)1,828 services
- Sarscov2 vac 50 mcg/0.5ml im (91322)1,376 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%
- Arthritis56%
- Depression55%
- Alzheimer's disease or dementia51%
- Anxiety48%
Hospitals where Dheeraj Mahajan works
Medicare's Facility Affiliation Data lists Dheeraj Mahajan 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.
- Loyola University Medical CenterMaywood, IL · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: listed by Medicare · CCN 140276
Practice locations
Addresses where Dheeraj Mahajan is enrolled with Medicare (CMS data updated October 2, 2026).
- 101 Madison St, Suite 300Oak Park, IL 60302 (708) 486‑2700
Group practices
Medicare enrollment lists Dheeraj Mahajan as a member of this group (CMS data updated October 2, 2026).
- Cimpar SC35 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Oak Park
Clinicians with the same Medicare primary specialty in Oak Park, IL — not a recommendation.
Other clinicians in Cimpar SC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1997 (29 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1831133693 |
| 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