Quick answers
- Where does Gregory L. Chen see patients?
- Medicare's clinician data lists 1 practice location in Hayward, CA. Call before your visit to confirm the address.
- What is Gregory L. Chen's specialty?
- Medicare lists Urology as the primary specialty.
- Does Gregory L. Chen accept Medicare assignment?
- Yes. Medicare's clinician data says Gregory 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 Gregory L. Chen?
- (510) 784-4000, as listed in official Medicare / NPI Registry data.
- What is Gregory L. Chen's NPI number?
- 1699853457. 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 Gregory L. Chen is enrolled with Medicare (CMS data updated 2026-10-02).
- 27303 Sleepy Hollow S AveHayward, CA 94545 (510) 784‑4000
Group practices
Medicare enrollment lists Gregory L. Chen as a member of this group (CMS data updated 2026-10-02).
- Permanente Medical Group Inc10,996 clinicians in the group
Specialties
- Urologyprimary
Other urologists in Hayward
Clinicians with the same Medicare primary specialty in Hayward, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Rush Medical College Of Rush University |
| Graduation year | 1992 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1699853457 |
| 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