Quick answers
- Which hospitals does William P. Klein work at?
- Medicare's official clinician data lists William P. Klein at 3 hospitals: Hoag Memorial Hospital Presbyterian, Memorialcare Orange Coast Medical Center and Memorialcare Saddleback Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does William P. Klein see patients?
- Medicare's clinician data lists 1 practice location in Newport Beach, CA. Call before your visit to confirm the address.
- What is William P. Klein's specialty?
- Medicare lists Internal Medicine as the primary specialty, and also Pulmonary Disease.
- Does William P. Klein accept Medicare assignment?
- Yes. Medicare's clinician data says William P. Klein 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 William P. Klein?
- (949) 274-8030, as listed in official Medicare / NPI Registry data.
- What is William P. Klein's NPI number?
- 1205834819. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where William P. Klein works
Medicare's Facility Affiliation Data lists William P. Klein at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Hoag Memorial Hospital PresbyterianNewport Beach, CA · Acute Care Hospital · CCN 050224
- Memorialcare Orange Coast Medical CenterFountain Valley, CA · Acute Care Hospital · CCN 050678
- Memorialcare Saddleback Medical CenterLaguna Hills, CA · Acute Care Hospital · CCN 050603
Practice locations
Addresses where William P. Klein is enrolled with Medicare (CMS data updated 2026-10-02).
- 1501 Superior Ave, Suite 111Newport Beach, CA 92663 (949) 274‑8030
Group practices
Medicare enrollment lists William P. Klein as a member of this group (CMS data updated 2026-10-02).
- Huntington Beach Internal Medicine Group Inc3 clinicians in the group
Specialties
- Internal Medicineprimary
- Pulmonary Diseasealso
Other internal medicine doctors in Newport Beach
Clinicians with the same Medicare primary specialty in Newport Beach, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of New York Downstate Medical Center |
| Graduation year | 1966 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1205834819 |
| 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