Quick answers
- Does Allison J. Hahr accept Medicare assignment?
- Yes. Medicare's clinician data says Allison J. Hahr 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 Allison J. Hahr see?
- In 2024, CMS data shows 1,355 Original Medicare patients and 44,830 services for Allison J. Hahr. This counts Original Medicare only and measures volume, not quality.
- What is Allison J. Hahr's NPI number?
- 1083774889. 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 Allison J. Hahr, 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 | 1,355 |
|---|---|
| Services billed to Medicare | 44,830 |
| Different services or procedures | 27 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Injection, romosozumab-aqqg, 1 mg (J3111)26,460 services
- Injection, denosumab, 1 mg (J0897)15,660 services
- Dxa bone density measurement of hip, pelvis, spine (77080)811 services
- Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)515 services
- Injection of drug or substance under skin or into muscle (96372)511 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 cholesterol72%
- Osteoporosis66%
- High blood pressure53%
- Arthritis43%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)25%
- Anxiety21%
Hospitals where Allison J. Hahr works
Medicare's Facility Affiliation Data lists Allison J. Hahr 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.
- Northwestern Lake Forest HospitalLake Forest, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140130
- Northwestern Medicine Central Dupage HospitalWinfield, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140242
- Northwestern Medicine Delnor Community HospitalGeneva, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140211
- Northwestern Memorial HospitalChicago, IL · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 140281
- Palos Community HospitalPalos Heights, IL · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 140062
Practice locations
Addresses where Allison J. Hahr is enrolled with Medicare (CMS data updated October 2, 2026). The first 5 of 23; the Medicare profile lists all.
- 1333 W Belmont AveChicago, IL 60657
- 1460 N Halsted St, Suite 504Chicago, IL 60642 (312) 926‑6146
- 1630 Sherman AveEvanston, IL 60201
- 233 S Gary AveBloomingdale, IL 60108 (630) 358‑4414
- 233 S Gary Ave, Suite 100Bloomingdale, IL 60108 (630) 225‑2663
Group practices
Medicare enrollment lists Allison J. Hahr as a member of this group (CMS data updated October 2, 2026).
- Northwestern Medical Faculty Foundation4,503 clinicians in the group
Specialties
- Endocrinologyprimary
- Internal Medicinealso
Other endocrinologists in Chicago
Clinicians with the same Medicare primary specialty in Chicago, IL — not a recommendation.
Other clinicians in Northwestern Medical Faculty Foundation
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Wisconsin School Of Medicine |
| Graduation year | 2002 (24 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) | 1083774889 |
| 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