Quick answers
- Where does Marianne K. Ryan see patients?
- Medicare's clinician data lists 2 practice locations, including Harbor City, CA. Call before your visit to confirm the address.
- What is Marianne K. Ryan's specialty?
- Medicare lists General Surgery as the primary specialty.
- Does Marianne K. Ryan accept Medicare assignment?
- Yes. Medicare's clinician data says Marianne K. Ryan 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 Marianne K. Ryan?
- (310) 325-5111, as listed in official Medicare / NPI Registry data.
- What is Marianne K. Ryan's NPI number?
- 1336216183. 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 Marianne K. Ryan is enrolled with Medicare (CMS data updated 2026-10-02).
- 25821 Vermont AveHarbor City, CA 90710 (310) 325‑5111
- 25825 Vermont AveHarbor City, CA 90710 (310) 325‑5111
Group practices
Medicare enrollment lists Marianne K. Ryan as a member of this group (CMS data updated 2026-10-02).
- Southern California Permanente Medical Group11,293 clinicians in the group
Specialties
- General Surgeryprimary
Other general surgeons in Harbor City
Clinicians with the same Medicare primary specialty in Harbor City, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Washington School Of Medicine |
| Graduation year | 1989 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1336216183 |
| 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