Quick answers
- Does Aileen G. Guillen accept Medicare assignment?
- Medicare's clinician data says Aileen G. Guillen may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
- What is Aileen G. Guillen's NPI number?
- 1427753946. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Aileen G. Guillen works
Medicare's Facility Affiliation Data lists Aileen G. Guillen at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Lac/Harbor-Ucla Medical CenterTorrance, CA · Acute Care Hospital · Medicare rating: 1 of 5 stars · Emergency services: listed by Medicare · CCN 050376
Practice locations
Addresses where Aileen G. Guillen is enrolled with Medicare (CMS data updated October 2, 2026).
- 12727 Brian CtCerritos, CA 90703
- 335 E Ave ILancaster, CA 93535
Specialties
- Emergency Medicineprimary
Other emergency medicine doctors in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2023 (3 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1427753946 |
| 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 October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- 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