Kathleen McMahon, DO

Medicare activity in 2024

Official CMS public-use data for Kathleen McMahon, 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.

Most frequent services

1. Emergency department visit with high level of medical decision making (99285)133 services
2. Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (93010)91 services
3. Emergency department visit with moderate level of medical decision making (99284)56 services
4. Critical care, first 30-74 minutes (99291)46 services
5. Emergency department visit with low level of medical decision making (99283)16 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 cholesterol73%
• Arthritis55%
• Diabetes43%
• Ischemic heart disease40%
• Chronic kidney disease39%

Hospitals where Kathleen McMahon works

Medicare's Facility Affiliation Data lists Kathleen McMahon 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.

• Cedar-Sinai Marina del Rey HospitalMarina del Rey, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050740
• NYU Langone HospitalsNew York, NY · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 330214

Practice locations

Addresses where Kathleen McMahon is enrolled with Medicare (CMS data updated October 2, 2026).

• 111 BroadwayNew York, NY 10006 (212) 263‑9700
• 4650 Lincoln BlvdMarina Del Rey, CA 90292 (310) 118‑5200

Group practices

Medicare enrollment lists Kathleen McMahon as a member of these groups (CMS data updated October 2, 2026).

• New York University6,134 clinicians in the group
• Mission Viejo Emergency Medical Associates, Inc.30 clinicians in the group

Specialties

• Emergency Medicineprimary

Find other Emergency Medicine doctors in New York →

Other emergency medicine doctors in New York

Clinicians with the same Medicare primary specialty in New York, NY — not a recommendation.

• Andrew P. Melnyk, DO
• Eli N. Cohen, DO
• Matthew A. Pius, MD
• Mateusz Ciejka, MD
• Marlis Gnirke, MD
• Oluchi I. King, MD
• Monisha Dilip, MD
• Elyse Lavine

All emergency medicine doctors in New York →

Other clinicians in New York University

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

• Inna I. Geyler, MD
• Nada G. Abou Fayssal, MD
• Nicole Kaloudis, PA
• Adam S. Jacobson, MD
• Claire M. Crossman
• Alexandra Dryer, MD

Clinician information

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