Chung-Ying Chen, MD

Medicare activity in 2024

Official CMS public-use data for Chung-Ying 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)72 services
2. Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (G0439)48 services
3. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)38 services
4. Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)14 services
5. New patient office or other outpatient visit with straightforward medical decision making, if using time, 15 minutes or more (99202)12 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 pressure58%
• High cholesterol58%
• Arthritis34%
• Diabetes21%
• Osteoporosis20%
• Ischemic heart disease18%

Practice locations

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

• 15400 Los Gatos BlvdLos Gatos, CA 95032 (408) 739‑6000
• 301 Old San Francisco RdSunnyvale, CA 94086 (408) 739‑6000
• 370 Distel CirLos Altos, CA 94022 (650) 254‑5200

Group practices

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

• Sutter Bay Medical Foundation3,829 clinicians in the group

Specialties

• Family Practiceprimary
• Internal Medicinealso

Find other Family Practice doctors in California →

Other family doctors in Los Gatos

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

• Kevin M. Haggerty, MD
• Smitha Kumar, MD
• Mary D. Defigard, MD
• Maria Delie T. Jumagdao Sakai, MD
• Barry Slater, MD
• Saumya Pandey, DO
• Sruthi Damodara, DO
• George A. Whang, DO

All family doctors in Los Gatos →

Other clinicians in Sutter Bay Medical Foundation

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

• Sung H. Chun, MD
• Ariela Hazan, MD
• Robert R. Johnson, MD
• Scott P. Wachhorst, MD
• Daniel L. Ouyang, MD
• George K. Lee, 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. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
2. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
4. Medicare Care Compare — official Medicare tool to look up clinicians