Quick answers
- Does Karen H. Ma accept Medicare assignment?
- Yes. Medicare's clinician data says Karen H. Ma 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 Karen H. Ma see?
- In 2024, CMS data shows 413 Original Medicare patients and 1,006 services for Karen H. Ma. This counts Original Medicare only and measures volume, not quality.
- What is Karen H. Ma's NPI number?
- 1124464789. 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 Karen H. Ma, 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 | 413 |
|---|---|
| Services billed to Medicare | 1,006 |
| Different services or procedures | 36 |
| Participating Medicare provider | Yes |
| Average age of these patients | 77 |
Most frequent services
- Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes (99233)385 services
- Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes (99223)327 services
- Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope (43239)48 services
- Diagnostic exam of esophagus, stomach, and/or upper small bowel using a flexible endoscope (43235)47 services
- Diagnostic exam of large bowel using a flexible endoscope (45378)28 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%
- Arthritis63%
- Diabetes49%
- Chronic kidney disease49%
- Ischemic heart disease48%
Hospitals where Karen H. Ma works
Medicare's Facility Affiliation Data lists Karen H. Ma 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.
- Elmhurst Memorial HospitalElmhurst, IL · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 140200
- Swedish HospitalChicago, IL · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 140114
Practice locations
Addresses where Karen H. Ma is enrolled with Medicare (CMS data updated October 2, 2026).
- 155 E Brush Hill RdElmhurst, IL 60126 (331) 221‑0096
Group practices
Medicare enrollment lists Karen H. Ma as a member of this group (CMS data updated October 2, 2026).
- Endeavor Health Medical Group3,350 clinicians in the group
Specialties
- Gastroenterologyprimary
- Internal Medicinealso
Other gastroenterologists in Elmhurst
Clinicians with the same Medicare primary specialty in Elmhurst, IL — not a recommendation.
Other clinicians in Endeavor Health Medical Group
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Graduation year | 2013 (13 years since medical school) |
|---|---|
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1124464789 |
| 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