Quick answers
- Which hospitals does Mark D. Shields work at?
- Medicare's official clinician data lists Mark D. Shields at 2 hospitals: Hoag Memorial Hospital Presbyterian and Memorialcare Saddleback Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark D. Shields see patients?
- Medicare's clinician data lists 2 practice locations, including Laguna Hills, CA. Call before your visit to confirm the address.
- What is Mark D. Shields's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Mark D. Shields accept Medicare assignment?
- Yes. Medicare's clinician data says Mark D. Shields 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 Mark D. Shields?
- (949) 588-8700, as listed in official Medicare / NPI Registry data.
- What is Mark D. Shields's NPI number?
- 1366411555. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Mark D. Shields works
Medicare's Facility Affiliation Data lists Mark D. Shields 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 Saddleback Medical CenterLaguna Hills, CA · Acute Care Hospital · CCN 050603
Practice locations
Addresses where Mark D. Shields is enrolled with Medicare (CMS data updated 2026-10-02).
- 24221 Calle De La Louisa, Suite 200Laguna Hills, CA 92653 (949) 588‑8700
- 24411 Health Ctr Dr, Suite 460Laguna Hills, CA 92653 (949) 443‑4303
Group practices
Medicare enrollment lists Mark D. Shields as a member of these groups (CMS data updated 2026-10-02).
- Healthcare Partners Affiliates Medical Group754 clinicians in the group
- Paloma Medical Group Inc19 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Laguna Hills
Clinicians with the same Medicare primary specialty in Laguna Hills, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, Geffen School Of Medicine |
| Graduation year | 1992 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1366411555 |
| 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