Quick answers
- Which hospitals does Sam S. Ahn work at?
- Medicare's official clinician data lists Sam S. Ahn at 3 hospitals: John Muir Medical Center - Walnut Creek Campus, Providence Queen of the Valley Medical Center and Sonoma Valley Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Sam S. Ahn see patients?
- Medicare's clinician data lists 1 practice location in Napa, CA. Call before your visit to confirm the address.
- What is Sam S. Ahn's specialty?
- Medicare lists Allergy/Immunology as the primary specialty, and also Internal Medicine.
- Does Sam S. Ahn accept Medicare assignment?
- Yes. Medicare's clinician data says Sam S. Ahn 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.
- Does Sam S. Ahn offer telehealth?
- Medicare's clinician data says Sam S. Ahn offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Sam S. Ahn?
- (707) 258-8100, as listed in official Medicare / NPI Registry data.
- What is Sam S. Ahn's NPI number?
- 1558423814. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Sam S. Ahn works
Medicare's Facility Affiliation Data lists Sam S. Ahn at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- John Muir Medical Center - Walnut Creek CampusWalnut Creek, CA · Acute Care Hospital · CCN 050180
- Providence Queen of the Valley Medical CenterNapa, CA · Acute Care Hospital · CCN 050009
- Sonoma Valley HospitalSonoma, CA · Acute Care Hospital · CCN 050090
Practice locations
Addresses where Sam S. Ahn is enrolled with Medicare (CMS data updated 2026-10-02).
- 1100 Pear Tree LnNapa, CA 94558 (707) 258‑8100
Group practices
Medicare enrollment lists Sam S. Ahn as a member of this group (CMS data updated 2026-10-02).
- North Bay Allergy and Asthma3 clinicians in the group
Specialties
- Allergy/Immunologyprimary
- Internal Medicinealso
Other allergist and immunologists in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Harvard Medical School |
| Graduation year | 2003 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1558423814 |
| 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- 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