Quick answers
- Where does Karen R. Simpson see patients?
- Medicare's clinician data lists 5 practice locations, including Fullerton, CA, Diamond Bar, CA and Brea, CA. Call before your visit to confirm the address.
- What is Karen R. Simpson's specialty?
- Medicare lists Dermatology as the primary specialty.
- Does Karen R. Simpson accept Medicare assignment?
- Yes. Medicare's clinician data says Karen R. Simpson 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 Karen R. Simpson?
- (714) 871-3006, as listed in official Medicare / NPI Registry data.
- What is Karen R. Simpson's NPI number?
- 1376544189. 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 Karen R. Simpson is enrolled with Medicare (CMS data updated 2026-10-02).
- 100 E Valencia Mesa Dr, Suite 105Fullerton, CA 92835 (714) 871‑3006
- 1514 Valley Vista DrDiamond Bar, CA 91765 (909) 860‑1144
- 1950 Sunny Crest Dr, Suite 2900Fullerton, CA 92835 (714) 992‑5350
- 955 W Imperial HwyBrea, CA 92821
- 955 W Imperial Hwy, Suite 110Brea, CA 92821 (714) 449‑6900
Group practices
Medicare enrollment lists Karen R. Simpson as a member of this group (CMS data updated 2026-10-02).
- Providence Medical Foundation1,466 clinicians in the group
Specialties
- Dermatologyprimary
Other dermatologists in Fullerton
Clinicians with the same Medicare primary specialty in Fullerton, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1991 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1376544189 |
| 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