Christopher R. Foss, MD

Medicare activity in 2024

Official CMS public-use data for Christopher R. Foss, 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. Injection, epoetin alfa, (for non-esrd use), 1000 units (J0885)1,900 services
2. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)199 services
3. Insertion of needle into vein for collection of blood sample (36415)167 services
4. Injection of drug or substance under skin or into muscle (96372)134 services
5. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)93 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%
• Diabetes57%
• Chronic kidney disease50%
• Arthritis47%
• Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)36%

Hospitals where Christopher R. Foss works

Medicare's Facility Affiliation Data lists Christopher R. Foss 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.

• Henry Mayo Newhall HospitalValencia, CA · Acute Care Hospital · Medicare rating: 2 of 5 stars · Emergency services: not listed by Medicare · CCN 050624

Practice locations

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

• 1520 San Pablo StLos Angeles, CA 90033 (800) 872‑2273
• 1520 San Pablo St, Fl 4Los Angeles, CA 90033 (800) 872‑2273
• 1520 San Pablo St 1st Floor NLos Angeles, CA 90033 (800) 872‑2273
• 25751 McBean PkwySanta Clarita, CA 91355

Group practices

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

• USC Care Medical Group Inc1,380 clinicians in the group

Specialties

• Hematology/Oncologyprimary
• Internal Medicinealso

Find other Hematology/Oncology doctors in California →

Other hematologist-oncologists in Los Angeles

Clinicians with the same Medicare primary specialty in Los Angeles, CA — not a recommendation.

• Jonathan W. Goldman, MD
• Araz Marachelian, MD
• Grant W. Jirka, MD
• Thomas C. Hofstra, MD
• Anas Raowas, MD
• Deborah J. Wong, MD
• Arash Naeim, MD
• Patricia Ganz, MD

All hematologist-oncologists in Los Angeles →

Other clinicians in USC Care Medical Group Inc

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

• George F. Hatch, MD
• Dominic Park, PT
• Aaron M. Yim, MD
• Monish Aron, MD
• Aaron Hewus
• Van Nguyen, 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