Quick answers
- Where does Mary L. Chen see patients?
- Medicare's clinician data lists 1 practice location in Walnut, CA. Call before your visit to confirm the address.
- What is Mary L. Chen's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Mary L. Chen accept Medicare assignment?
- Yes. Medicare's clinician data says Mary L. Chen accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Mary L. Chen?
- (626) 810-6777, as listed in official Medicare / NPI Registry data.
- What is Mary L. Chen's NPI number?
- 1568445229. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where Mary L. Chen is enrolled with Medicare (CMS data updated 2026-10-02).
- 18780 Amar Rd, Suite 107Walnut, CA 91789 (626) 810‑6777
Specialties
- Internal Medicineprimary
Other internal medicine doctors in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1985 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1568445229 |
| Corrections | Report 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
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians