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General Surgery

Sheryl J. Kwak, MD

Sees patients in Fontana, CA · California

Summary

Dr. Sheryl J. Kwak, MD is a general surgeon at 9961 Sierra Ave, Fontana, CA 92335. Phone: (909) 427-5000. Accepts Medicare assignment. NPI 1104065259. Source: CMS National Downloadable File, updated October 2, 2026.

  • Specialty: General surgeon (Medicare lists General Surgery)
  • Address: 9961 Sierra Ave, Fontana, CA 92335 · Directions
  • Phone: (909) 427‑5000
  • Medicare: Accepts Medicare assignment
  • Group practice: Southern California Permanente Medical Group
  • Medical school: University Of California, Davis School Of Medicine · graduated 2008 (18 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Sheryl J. Kwak, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Sheryl J. Kwak accept Medicare assignment?
Yes. Medicare's clinician data says Sheryl J. Kwak accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
What is Sheryl J. Kwak's NPI number?
1104065259. 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 Sheryl J. Kwak is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Sheryl J. Kwak as a member of this group (CMS data updated October 2, 2026).

  • Southern California Permanente Medical Group11,293 clinicians in the group

Specialties

Find other General Surgery doctors in California →

Other general surgeons in Fontana

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

All general surgeons in Fontana →

Other clinicians in Southern California Permanente Medical Group

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

Clinician information

CredentialMD
Medical schoolUniversity Of California, Davis School Of Medicine
Graduation year2008 (18 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1104065259
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. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  2. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  3. Medicare Care Compare — official Medicare tool to look up clinicians