Tien-Chun Chen, MD

Medicare activity in 2024

Official CMS public-use data for Tien-Chun Chen, 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. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)187 services
2. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)155 services
3. Biopsy of large bowel using a flexible endoscope (45380)131 services
4. New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more (99204)113 services
5. Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope (43239)99 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%
• Diabetes49%
• Arthritis46%
• Chronic kidney disease42%
• Osteoporosis30%

Hospitals where Tien-Chun Chen works

Medicare's Facility Affiliation Data lists Tien-Chun Chen 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.

• USC Arcadia HospitalArcadia, CA · Acute Care Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 050238

Practice locations

Addresses where Tien-Chun Chen is enrolled with Medicare (CMS data updated October 2, 2026).

• 207 S Santa Anita St, Suite P15San Gabriel, CA 91776 (626) 898‑4560
• 709 N Hill St, Suite 18Los Angeles, CA 90012 (213) 328‑0819

Group practices

Medicare enrollment lists Tien-Chun Chen as a member of this group (CMS data updated October 2, 2026).

• Genesis Healthcare Partners PC228 clinicians in the group

Specialties

• Gastroenterologyprimary
• Internal Medicinealso

Find other Gastroenterology doctors in California →

Other gastroenterologists in California

Clinicians with the same Medicare primary specialty in California — not a recommendation.

• Ken D. Nguyen, MD
• Chester D. Zahn, MD
• Ellie Y. Chen, MD
• Mehrdad Vosoghi, MD
• David Limsui, MD
• Sunitha Musuku, MD
• Matthew E. Viernes, MD
• Yehia Naga, MD

All gastroenterologists in California →

Other clinicians in Genesis Healthcare Partners PC

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

• Dean La Barba, MD
• Adrianne Lajoie, MD
• Henry A. Fisher, MD
• Reena P. Vasquez, CNA
• Lloyd A. Ligayo, DC
• Galen Cortina, 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