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Internal Medicine

Stacy D. Ly, MD

Works at hospitals in Concord, CA · Walnut Creek, CA · California

Summary

Stacy D. Ly, MD (Internal Medicine) is listed by Medicare at 2 hospitals in Concord, CA and Walnut Creek, CA. NPI 1649458795. Medicare data says the clinician accepts Medicare assignment. Source: CMS Facility Affiliation Data, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Stacy D. Ly, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

Internal MedicinePrimary specialty
YesAccepts Medicare assignment
20Years since medical school (graduated 2006)
George Washington University School Of MedicineMedical school
FemaleGender (as listed)
John Muir Physician NetworkGroup practice

Quick answers

Which hospitals does Stacy D. Ly work at?
Medicare's official clinician data lists Stacy D. Ly at 2 hospitals: John Muir Medical Center - Concord Campus and John Muir Medical Center - Walnut Creek Campus. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Stacy D. Ly see patients?
Medicare's clinician data lists 1 practice location in Concord, CA. Call before your visit to confirm the address.
What is Stacy D. Ly's specialty?
Medicare lists Internal Medicine as the primary specialty.
Does Stacy D. Ly accept Medicare assignment?
Yes. Medicare's clinician data says Stacy D. Ly 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 Stacy D. Ly?
(925) 674-0500, as listed in official Medicare / NPI Registry data.
What is Stacy D. Ly's NPI number?
1649458795. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Stacy D. Ly works

Medicare's Facility Affiliation Data lists Stacy D. Ly at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.

Practice locations

Addresses where Stacy D. Ly is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Stacy D. Ly as a member of this group (CMS data updated 2026-10-02).

  • John Muir Physician Network494 clinicians in the group

Specialties

Find other Internal Medicine doctors in California →

Other internal medicine doctors in Concord

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

All internal medicine doctors in Concord →

Clinician information

CredentialMD
Medical schoolGeorge Washington University School Of Medicine
Graduation year2006
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1649458795
CorrectionsReport 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

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
  2. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  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