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Emergency Medicine

Alison R. Stewart, MD

Works at hospitals in Whittier, CA · California

Summary

Dr. Alison R. Stewart, MD is an emergency medicine doctor at 1701 Santa Anita Ave, South El Monte, CA 91733. Phone: (626) 579-7777. Accepts Medicare assignment. In 2024, Alison R. Stewart had 277 Original Medicare patients and 565 services. NPI 1487735163. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

  • Specialty: Emergency medicine doctor (Medicare lists Emergency Medicine)
  • Address: 1701 Santa Anita Ave, South El Monte, CA 91733 · Directions (1 more location)
  • Phone: (626) 579‑7777
  • Medicare: Accepts Medicare assignment
  • Hospital: Whittier Hospital Medical Center
  • Group practice: Gem Medical Group Corporation
  • Medical school: graduated 2000 (26 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Alison R. Stewart, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Alison R. Stewart accept Medicare assignment?
Yes. Medicare's clinician data says Alison R. Stewart 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 Alison R. Stewart see?
In 2024, CMS data shows 277 Original Medicare patients and 565 services for Alison R. Stewart. This counts Original Medicare only and measures volume, not quality.
What is Alison R. Stewart's NPI number?
1487735163. 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 Alison R. Stewart, 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 patients277
Services billed to Medicare565
Different services or procedures13
Participating Medicare providerYes
Average age of these patients76

Most frequent services

  1. Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (93010)202 services
  2. Critical care, first 30-74 minutes (99291)183 services
  3. Emergency department visit with high level of medical decision making (99285)81 services
  4. Electrocardiogram (ecg) 1 to 3 leads with review by physician only (93042)46 services
  5. Emergency department visit with moderate level of medical decision making (99284)25 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%
  • Diabetes60%
  • Chronic kidney disease50%
  • Arthritis49%
  • Heart failure49%

Hospitals where Alison R. Stewart works

Medicare's Facility Affiliation Data lists Alison R. Stewart 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.

Practice locations

Addresses where Alison R. Stewart is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Alison R. Stewart as a member of this group (CMS data updated October 2, 2026).

  • Gem Medical Group Corporation57 clinicians in the group

Specialties

Find other Emergency Medicine doctors in California →

Other emergency medicine doctors in South El Monte

Clinicians with the same Medicare primary specialty in South El Monte, CA — not a recommendation.

All emergency medicine doctors in South El Monte →

Other clinicians in Gem Medical Group Corporation

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialMD
Graduation year2000 (26 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1487735163
CorrectionsReport 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

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
  2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
  3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  6. Medicare Care Compare — official Medicare tool to look up clinicians